Notation by work

Paper VII: Quantum Seed Calculus

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1144 symbol spellings in 2761 mathematical passages across 53 selected source files. Subscripts and superscripts have their own entries alongside their base symbols.

The same symbol can have several meanings here. A passage classified as a definition may define another part of its expression. Read the linked context before assigning a meaning.

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*Definition passage · 272 passages

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  • Definition passage: Finite quantum seed system · Read passage · 01_finite_core.tex, line 54

    inition:001 A finite quantum seed system is a tuple Q= ( H, ψ_0, O, R, {P_ℓ,α}, H, τ ), where H is a finite-dimensional Hilbert space, ψ_0∈ H is a nonzero seed, O is the declared operator grammar, R is a collection of algebraic or physical constraints, {P_ℓ,α} is an exact packet system at each refinement level, H=H^* is a Hamiltonian when dynamics are present, and τ specifies the topology used in a later completion.

    Exact mathematical passage
    H=H^*
+Definition passage · 164 passages

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  • Definition passage: Finite quantum refinement tower · Read passage · 02_strengthened.tex, line 2345

    [Finite quantum refinement tower] A finite quantum refinement tower consists of Hilbert spaces H_ℓ, isometries R_ℓ: H_ℓ⟶ H_ℓ+1, self adjoint Hamiltonians H_ℓ, packet projectors P_ℓ,a, constraints C_ℓ,r, and positive transfer operators T_ℓ. Exact compatibility means that every declared object intertwines with R_ℓ. Approximate compatibility is recorded by the corresponding operator norm defects.

    Exact mathematical passage
    
    R_\ell:\Hcal_\ell\longrightarrow\Hcal_{\ell+1},
    
=Definition passage · 1076 passages

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  • Definition passage: Finite quantum seed system · Read passage · 01_finite_core.tex, line 42

    [Finite quantum seed system] A finite quantum seed system is a tuple Q= ( H, ψ_0, O, R, {P_ℓ,α}, H, τ ), where H is a finite-dimensional Hilbert space, ψ_0∈ H is a nonzero seed, O is the declared operator grammar, R is a collection of algebraic or physical constraints, {P_ℓ,α} is an exact packet system at each refinement level, H=H^* is a Hamiltonian when dynamics are present, and τ specifies the topology used in a later completion.

    Exact mathematical passage
    
    \mathfrak Q=
    \left(
    \cH,
    \psi_0,
    \cO,
    \cR,
    \{P_{\ell,\alpha}\},
    H,
    \tau
    \right),
    
ADefinition passage · 133 passages

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  • Definition passage: Finite quantum seed system · Read passage · 02_strengthened.tex, line 93

    [Finite quantum seed system] A finite quantum seed system is a triple ( H, A,S), where H is a finite dimensional Hilbert space, A⊆End( H) is a unital star subalgebra, and S⊆ H is a finite set. Its generated hull is A S = span{Aψ:A∈ A, ψ∈ S}. The seed set is cyclic when A S= H. The quantum seed rank is the least cardinality of a cyclic seed set.

    Exact mathematical passage
    
    \Acal S
    =
    \operatorname{span}\{A\psi:A\in\Acal,\ \psi\in S\}.
    
aDefinition passage · 379 passages

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  • Definition passage: Two sided operator packet · Read passage · 02_strengthened.tex, line 944

    [Two sided operator packet] For a complete orthogonal family (P_a), define P_ab(X)=P_aXP_b. The range B_ab=P_aEnd( H)P_b is the operator packet with output address a and input address b.

    Exact mathematical passage
    (P_a)
\absDefinition passage · 26 passages

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  • Definition passage: Einstein infrared criterion · Read passage · 02_strengthened.tex, line 2558

    [Einstein infrared criterion] A quantum geometric tower meets an Einstein infrared criterion only if an effective action is controlled at long wavelengths and has an expansion whose leading geometric terms take the form Γ_rm eff[g] = ∫ sqrtabs g ( Λ + frac116π GR + controlled higher order terms ) d^dx. Here the volume coefficient includes the sign and normalization written explicitly in the cosmological term in Part I. The expansion must respect the limiting gauge identities and must include an …

    Exact mathematical passage
    
    \Gamma_{\rm eff}[g]
    =
    \int
    \sqrt{\abs g}
    \left(
    \Lambda
    +
    \frac{1}{16\pi G}R
    +
    \text{controlled higher order terms}
    \right)
    \dd^dx.
    
\AcalDefinition passage · 12 passages

Search aliases: Acal A mathcal

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  • Definition passage: Finite quantum seed system · Read passage · 02_strengthened.tex, line 89

    [Finite quantum seed system] A finite quantum seed system is a triple ( H, A,S), where H is a finite dimensional Hilbert space, A⊆End( H) is a unital star subalgebra, and S⊆ H is a finite set. Its generated hull is A S = span{Aψ:A∈ A, ψ∈ S}. The seed set is cyclic when A S= H. The quantum seed rank is the least cardinality of a cyclic seed set.

    Exact mathematical passage
    
    (\Hcal,\Acal,S),
    
BDefinition passage · 85 passages

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  • Definition passage: Feshbach map and self energy · Read passage · 02_strengthened.tex, line 1502

    [Feshbach map and self energy] For z∉Spec D, define Σ(z)=B(z-D)^-1B^* and F_P(z)=z-A-Σ(z).

    Exact mathematical passage
    
    \Sigma(z)=B(z-D)^{-1}B^*
    
bDefinition passage · 133 passages

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  • Definition passage: Two sided operator packet · Read passage · 02_strengthened.tex, line 945

    [Two sided operator packet] For a complete orthogonal family (P_a), define P_ab(X)=P_aXP_b. The range B_ab=P_aEnd( H)P_b is the operator packet with output address a and input address b.

    Exact mathematical passage
    
    \Pcal_{ab}(X)=P_aXP_b.
    
B^*Definition passage · 27 passages

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  • Definition passage: Feshbach map and self energy · Read passage · 02_strengthened.tex, line 1502

    [Feshbach map and self energy] For z∉Spec D, define Σ(z)=B(z-D)^-1B^* and F_P(z)=z-A-Σ(z).

    Exact mathematical passage
    
    \Sigma(z)=B(z-D)^{-1}B^*
    
\BcalDefinition passage · 1 passage

Search aliases: Bcal B mathcal

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  • Definition passage: Two sided operator packet · Read passage · 02_strengthened.tex, line 949

    [Two sided operator packet] For a complete orthogonal family (P_a), define P_ab(X)=P_aXP_b. The range B_ab=P_aEnd( H)P_b is the operator packet with output address a and input address b.

    Exact mathematical passage
    
    \Bcal_{ab}=P_a\End(\Hcal)P_b
    
\Bcal_{ab}Definition passage · 1 passage

Search aliases: Bcal_ab B_ab Bcal mathcal

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  • Definition passage: Two sided operator packet · Read passage · 02_strengthened.tex, line 949

    [Two sided operator packet] For a complete orthogonal family (P_a), define P_ab(X)=P_aXP_b. The range B_ab=P_aEnd( H)P_b is the operator packet with output address a and input address b.

    Exact mathematical passage
    
    \Bcal_{ab}=P_a\End(\Hcal)P_b
    
CDefinition passage · 182 passages

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  • Definition passage: Universal closure obstruction · Read passage · 02_strengthened.tex, line 2186

    [Universal closure obstruction] Let q_ c:End( H)⟶End( H)/ c be the quotient map. Define Ob_ab^rm cl = q_ c([C_a,C_b]).

    Exact mathematical passage
    
    \Ob_{ab}^{\rm cl}
    =
    q_{\mathfrak c}([C_a,C_b]).
    
\mathfrak cDefinition passage · 6 passages

Search aliases: c mathfrak

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  • Definition passage: Universal closure obstruction · Read passage · 02_strengthened.tex, line 2182

    [Universal closure obstruction] Let q_ c:End( H)⟶End( H)/ c be the quotient map. Define Ob_ab^rm cl = q_ c([C_a,C_b]).

    Exact mathematical passage
    
    q_{\mathfrak c}:\End(\Hcal)\longrightarrow\End(\Hcal)/\mathfrak c
    
cDefinition passage · 65 passages

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  • Definition passage: Approximate Knill Laflamme defect · Read passage · 02_strengthened.tex, line 1423

    [Approximate Knill Laflamme defect] For a finite error family, define the following defect. When the family is empty, assign the maximum the value zero. ε_rm KL = max_a,b inf_c∈ C normPE_a^*E_bP-cP.

    Exact mathematical passage
    
    \varepsilon_{\rm KL}
    =
    \max_{a,b}
    \inf_{c\in\CC}
    \norm{PE_a^*E_bP-cP}.
    
C_aDefinition passage · 25 passages

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  • Definition passage: Universal closure obstruction · Read passage · 02_strengthened.tex, line 2186

    [Universal closure obstruction] Let q_ c:End( H)⟶End( H)/ c be the quotient map. Define Ob_ab^rm cl = q_ c([C_a,C_b]).

    Exact mathematical passage
    
    \Ob_{ab}^{\rm cl}
    =
    q_{\mathfrak c}([C_a,C_b]).
    
C_bDefinition passage · 11 passages

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  • Definition passage: Universal closure obstruction · Read passage · 02_strengthened.tex, line 2186

    [Universal closure obstruction] Let q_ c:End( H)⟶End( H)/ c be the quotient map. Define Ob_ab^rm cl = q_ c([C_a,C_b]).

    Exact mathematical passage
    
    \Ob_{ab}^{\rm cl}
    =
    q_{\mathfrak c}([C_a,C_b]).
    
C_cDefinition passage · 7 passages

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  • Definition passage: Anomaly free continuum constraint system · Read passage · 02_strengthened.tex, line 2540

    [Anomaly free continuum constraint system] A continuum constraint system consists of a Hilbert space, a common invariant dense domain D, and operators C_a on D. It is anomaly free for prescribed structure coefficients when [C_a,C_b]ψ = i∑_cf_ab^phantomabcC_cψ for every ψ∈ D, and when the associated gauge evolution is defined on the physical quotient or physical subspace.

    Exact mathematical passage
    
    [C_a,C_b]\psi
    =
    \ii\sum_cf_{ab}^{\phantom{ab}c}C_c\psi
    
C_{\ell,r}Definition passage · 1 passage

Search aliases: C_ℓ,r ell

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  • Definition passage: Finite quantum refinement tower · Read passage · 02_strengthened.tex, line 2348

    [Finite quantum refinement tower] A finite quantum refinement tower consists of Hilbert spaces H_ℓ, isometries R_ℓ: H_ℓ⟶ H_ℓ+1, self adjoint Hamiltonians H_ℓ, packet projectors P_ℓ,a, constraints C_ℓ,r, and positive transfer operators T_ℓ. Exact compatibility means that every declared object intertwines with R_ℓ. Approximate compatibility is recorded by the corresponding operator norm defects.

    Exact mathematical passage
    C_{\ell,r}
\CCDefinition passage · 41 passages

Search aliases: CC C mathbb

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  • Definition passage: Code compression obstruction · Read passage · 02_strengthened.tex, line 1277

    [Code compression obstruction] Let q_P:End( C)⟶End( C)/( C I_ C) be the quotient map. Define Ob_P(A)=q_P(PAP). Equivalently, one may use the traceless representative o_P(A) = PAP- fracTr(PAP)kP.

    Exact mathematical passage
    
    q_P:\End(\Ccal)\longrightarrow\End(\Ccal)/(\CC I_{\Ccal})
    
\CcalDefinition passage · 4 passages

Search aliases: Ccal C mathcal

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  • Definition passage: Code compression obstruction · Read passage · 02_strengthened.tex, line 1277

    [Code compression obstruction] Let q_P:End( C)⟶End( C)/( C I_ C) be the quotient map. Define Ob_P(A)=q_P(PAP). Equivalently, one may use the traceless representative o_P(A) = PAP- fracTr(PAP)kP.

    Exact mathematical passage
    
    q_P:\End(\Ccal)\longrightarrow\End(\Ccal)/(\CC I_{\Ccal})
    
\cHDefinition passage · 18 passages

Search aliases: cH H mathcal

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  • Definition passage: Finite quantum seed system · Read passage · 01_finite_core.tex, line 42

    [Finite quantum seed system] A finite quantum seed system is a tuple Q= ( H, ψ_0, O, R, {P_ℓ,α}, H, τ ), where H is a finite-dimensional Hilbert space, ψ_0∈ H is a nonzero seed, O is the declared operator grammar, R is a collection of algebraic or physical constraints, {P_ℓ,α} is an exact packet system at each refinement level, H=H^* is a Hamiltonian when dynamics are present, and τ specifies the topology used in a later completion.

    Exact mathematical passage
    
    \mathfrak Q=
    \left(
    \cH,
    \psi_0,
    \cO,
    \cR,
    \{P_{\ell,\alpha}\},
    H,
    \tau
    \right),
    
\cODefinition passage · 5 passages

Search aliases: cO O mathcal

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  • Definition passage: Finite quantum seed system · Read passage · 01_finite_core.tex, line 42

    [Finite quantum seed system] A finite quantum seed system is a tuple Q= ( H, ψ_0, O, R, {P_ℓ,α}, H, τ ), where H is a finite-dimensional Hilbert space, ψ_0∈ H is a nonzero seed, O is the declared operator grammar, R is a collection of algebraic or physical constraints, {P_ℓ,α} is an exact packet system at each refinement level, H=H^* is a Hamiltonian when dynamics are present, and τ specifies the topology used in a later completion.

    Exact mathematical passage
    
    \mathfrak Q=
    \left(
    \cH,
    \psi_0,
    \cO,
    \cR,
    \{P_{\ell,\alpha}\},
    H,
    \tau
    \right),
    
\cRDefinition passage · 6 passages

Search aliases: cR R mathcal

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  • Definition passage: Finite quantum seed system · Read passage · 01_finite_core.tex, line 42

    [Finite quantum seed system] A finite quantum seed system is a tuple Q= ( H, ψ_0, O, R, {P_ℓ,α}, H, τ ), where H is a finite-dimensional Hilbert space, ψ_0∈ H is a nonzero seed, O is the declared operator grammar, R is a collection of algebraic or physical constraints, {P_ℓ,α} is an exact packet system at each refinement level, H=H^* is a Hamiltonian when dynamics are present, and τ specifies the topology used in a later completion.

    Exact mathematical passage
    
    \mathfrak Q=
    \left(
    \cH,
    \psi_0,
    \cO,
    \cR,
    \{P_{\ell,\alpha}\},
    H,
    \tau
    \right),
    
DDefinition passage · 90 passages

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  • Definition passage: Feshbach map and self energy · Read passage · 02_strengthened.tex, line 1501

    [Feshbach map and self energy] For z∉Spec D, define Σ(z)=B(z-D)^-1B^* and F_P(z)=z-A-Σ(z).

    Exact mathematical passage
    z\notin\Spec D
dDefinition passage · 147 passages

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  • Definition passage: Heat trace and spectral dimension · Read passage · 02_strengthened.tex, line 1961

    [Heat trace and spectral dimension] Let the eigenvalues of L be λ_1,…,λ_N, with at least one zero eigenvalue. Define Z_L(t)=Tr( e^-tL) and d_L(t) =-2frac dlog Z_L(t) dlog t = 2t fracTr(L e^-tL)Tr( e^-tL).

    Exact mathematical passage
    
    d_L(t)
    =-2\frac{\dd\log Z_L(t)}{\dd\log t}
    =
    2t
    \frac{\Tr(L\e^{-tL})}{\Tr(\e^{-tL})}.
    
d_LDefinition passage · 5 passages

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  • Definition passage: Heat trace and spectral dimension · Read passage · 02_strengthened.tex, line 1961

    [Heat trace and spectral dimension] Let the eigenvalues of L be λ_1,…,λ_N, with at least one zero eigenvalue. Define Z_L(t)=Tr( e^-tL) and d_L(t) =-2frac dlog Z_L(t) dlog t = 2t fracTr(L e^-tL)Tr( e^-tL).

    Exact mathematical passage
    
    d_L(t)
    =-2\frac{\dd\log Z_L(t)}{\dd\log t}
    =
    2t
    \frac{\Tr(L\e^{-tL})}{\Tr(\e^{-tL})}.
    
\DcalDefinition passage · 10 passages

Search aliases: Dcal D mathcal

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  • Definition passage: Packet dephasing · Read passage · 02_strengthened.tex, line 992

    [Packet dephasing] The packet dephasing map is D_ P(X)=∑_aP_aXP_a.

    Exact mathematical passage
    
    \Dcal_{\Pcal}(X)=\sum_aP_aXP_a.
    
\Dcal_{\Pcal}Definition passage · 7 passages

Search aliases: Dcal_Pcal D_ P Dcal Pcal mathcal mathcal

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  • Definition passage: Packet dephasing · Read passage · 02_strengthened.tex, line 992

    [Packet dephasing] The packet dephasing map is D_ P(X)=∑_aP_aXP_a.

    Exact mathematical passage
    
    \Dcal_{\Pcal}(X)=\sum_aP_aXP_a.
    
\ddDefinition passage · 30 passages

Search aliases: dd d mathrm

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  • Definition passage: Heat trace and spectral dimension · Read passage · 02_strengthened.tex, line 1961

    [Heat trace and spectral dimension] Let the eigenvalues of L be λ_1,…,λ_N, with at least one zero eigenvalue. Define Z_L(t)=Tr( e^-tL) and d_L(t) =-2frac dlog Z_L(t) dlog t = 2t fracTr(L e^-tL)Tr( e^-tL).

    Exact mathematical passage
    
    d_L(t)
    =-2\frac{\dd\log Z_L(t)}{\dd\log t}
    =
    2t
    \frac{\Tr(L\e^{-tL})}{\Tr(\e^{-tL})}.
    
\dd^dDefinition passage · 1 passage

Search aliases: dd^d d^d dd mathrm

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  • Definition passage: Einstein infrared criterion · Read passage · 02_strengthened.tex, line 2558

    [Einstein infrared criterion] A quantum geometric tower meets an Einstein infrared criterion only if an effective action is controlled at long wavelengths and has an expansion whose leading geometric terms take the form Γ_rm eff[g] = ∫ sqrtabs g ( Λ + frac116π GR + controlled higher order terms ) d^dx. Here the volume coefficient includes the sign and normalization written explicitly in the cosmological term in Part I. The expansion must respect the limiting gauge identities and must include an …

    Exact mathematical passage
    
    \Gamma_{\rm eff}[g]
    =
    \int
    \sqrt{\abs g}
    \left(
    \Lambda
    +
    \frac{1}{16\pi G}R
    +
    \text{controlled higher order terms}
    \right)
    \dd^dx.
    
EDefinition passage · 129 passages

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  • Definition passage: Approximate Knill Laflamme defect · Read passage · 02_strengthened.tex, line 1423

    [Approximate Knill Laflamme defect] For a finite error family, define the following defect. When the family is empty, assign the maximum the value zero. ε_rm KL = max_a,b inf_c∈ C normPE_a^*E_bP-cP.

    Exact mathematical passage
    
    \varepsilon_{\rm KL}
    =
    \max_{a,b}
    \inf_{c\in\CC}
    \norm{PE_a^*E_bP-cP}.
    
\eDefinition passage · 48 passages

Search aliases: e mathrm

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  • Definition passage: Heat trace and spectral dimension · Read passage · 02_strengthened.tex, line 1957

    [Heat trace and spectral dimension] Let the eigenvalues of L be λ_1,…,λ_N, with at least one zero eigenvalue. Define Z_L(t)=Tr( e^-tL) and d_L(t) =-2frac dlog Z_L(t) dlog t = 2t fracTr(L e^-tL)Tr( e^-tL).

    Exact mathematical passage
    
    Z_L(t)=\Tr(\e^{-tL})
    
eDefinition passage · 65 passages

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  • Definition passage: Einstein infrared criterion · Read passage · 02_strengthened.tex, line 2558

    [Einstein infrared criterion] A quantum geometric tower meets an Einstein infrared criterion only if an effective action is controlled at long wavelengths and has an expansion whose leading geometric terms take the form Γ_rm eff[g] = ∫ sqrtabs g ( Λ + frac116π GR + controlled higher order terms ) d^dx. Here the volume coefficient includes the sign and normalization written explicitly in the cosmological term in Part I. The expansion must respect the limiting gauge identities and must include an …

    Exact mathematical passage
    
    \Gamma_{\rm eff}[g]
    =
    \int
    \sqrt{\abs g}
    \left(
    \Lambda
    +
    \frac{1}{16\pi G}R
    +
    \text{controlled higher order terms}
    \right)
    \dd^dx.
    
\e^{-tL}Definition passage · 7 passages

Search aliases: e^-tL e mathrm

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  • Definition passage: Heat trace and spectral dimension · Read passage · 02_strengthened.tex, line 1957

    [Heat trace and spectral dimension] Let the eigenvalues of L be λ_1,…,λ_N, with at least one zero eigenvalue. Define Z_L(t)=Tr( e^-tL) and d_L(t) =-2frac dlog Z_L(t) dlog t = 2t fracTr(L e^-tL)Tr( e^-tL).

    Exact mathematical passage
    
    Z_L(t)=\Tr(\e^{-tL})
    
E_a^*Definition passage · 25 passages

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  • Definition passage: Approximate Knill Laflamme defect · Read passage · 02_strengthened.tex, line 1423

    [Approximate Knill Laflamme defect] For a finite error family, define the following defect. When the family is empty, assign the maximum the value zero. ε_rm KL = max_a,b inf_c∈ C normPE_a^*E_bP-cP.

    Exact mathematical passage
    
    \varepsilon_{\rm KL}
    =
    \max_{a,b}
    \inf_{c\in\CC}
    \norm{PE_a^*E_bP-cP}.
    
E_bDefinition passage · 20 passages

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  • Definition passage: Approximate Knill Laflamme defect · Read passage · 02_strengthened.tex, line 1423

    [Approximate Knill Laflamme defect] For a finite error family, define the following defect. When the family is empty, assign the maximum the value zero. ε_rm KL = max_a,b inf_c∈ C normPE_a^*E_bP-cP.

    Exact mathematical passage
    
    \varepsilon_{\rm KL}
    =
    \max_{a,b}
    \inf_{c\in\CC}
    \norm{PE_a^*E_bP-cP}.
    
\EndDefinition passage · 19 passages

Search aliases: End operatorname

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  • Definition passage: Finite quantum seed system · Read passage · 02_strengthened.tex, line 92

    [Finite quantum seed system] A finite quantum seed system is a triple ( H, A,S), where H is a finite dimensional Hilbert space, A⊆End( H) is a unital star subalgebra, and S⊆ H is a finite set. Its generated hull is A S = span{Aψ:A∈ A, ψ∈ S}. The seed set is cyclic when A S= H. The quantum seed rank is the least cardinality of a cyclic seed set.

    Exact mathematical passage
    \Acal\subseteq\End(\Hcal)
FDefinition passage · 57 passages

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  • Definition passage: Feshbach map and self energy · Read passage · 02_strengthened.tex, line 1506

    [Feshbach map and self energy] For z∉Spec D, define Σ(z)=B(z-D)^-1B^* and F_P(z)=z-A-Σ(z).

    Exact mathematical passage
    
    F_P(z)=z-A-\Sigma(z).
    
fDefinition passage · 21 passages

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  • Definition passage: Anomaly free continuum constraint system · Read passage · 02_strengthened.tex, line 2540

    [Anomaly free continuum constraint system] A continuum constraint system consists of a Hilbert space, a common invariant dense domain D, and operators C_a on D. It is anomaly free for prescribed structure coefficients when [C_a,C_b]ψ = i∑_cf_ab^phantomabcC_cψ for every ψ∈ D, and when the associated gauge evolution is defined on the physical quotient or physical subspace.

    Exact mathematical passage
    
    [C_a,C_b]\psi
    =
    \ii\sum_cf_{ab}^{\phantom{ab}c}C_c\psi
    
f_{ab}^{\phantom{ab}c}Definition passage · 6 passages

Search aliases: f_ab^phantomabc phantom

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  • Definition passage: Anomaly free continuum constraint system · Read passage · 02_strengthened.tex, line 2540

    [Anomaly free continuum constraint system] A continuum constraint system consists of a Hilbert space, a common invariant dense domain D, and operators C_a on D. It is anomaly free for prescribed structure coefficients when [C_a,C_b]ψ = i∑_cf_ab^phantomabcC_cψ for every ψ∈ D, and when the associated gauge evolution is defined on the physical quotient or physical subspace.

    Exact mathematical passage
    
    [C_a,C_b]\psi
    =
    \ii\sum_cf_{ab}^{\phantom{ab}c}C_c\psi
    
F_PDefinition passage · 12 passages

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  • Definition passage: Feshbach map and self energy · Read passage · 02_strengthened.tex, line 1506

    [Feshbach map and self energy] For z∉Spec D, define Σ(z)=B(z-D)^-1B^* and F_P(z)=z-A-Σ(z).

    Exact mathematical passage
    
    F_P(z)=z-A-\Sigma(z).
    
GDefinition passage · 22 passages

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  • Definition passage: Einstein infrared criterion · Read passage · 02_strengthened.tex, line 2558

    [Einstein infrared criterion] A quantum geometric tower meets an Einstein infrared criterion only if an effective action is controlled at long wavelengths and has an expansion whose leading geometric terms take the form Γ_rm eff[g] = ∫ sqrtabs g ( Λ + frac116π GR + controlled higher order terms ) d^dx. Here the volume coefficient includes the sign and normalization written explicitly in the cosmological term in Part I. The expansion must respect the limiting gauge identities and must include an …

    Exact mathematical passage
    
    \Gamma_{\rm eff}[g]
    =
    \int
    \sqrt{\abs g}
    \left(
    \Lambda
    +
    \frac{1}{16\pi G}R
    +
    \text{controlled higher order terms}
    \right)
    \dd^dx.
    
gDefinition passage · 28 passages

Search aliases: g

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  • Definition passage: Einstein infrared criterion · Read passage · 02_strengthened.tex, line 2558

    [Einstein infrared criterion] A quantum geometric tower meets an Einstein infrared criterion only if an effective action is controlled at long wavelengths and has an expansion whose leading geometric terms take the form Γ_rm eff[g] = ∫ sqrtabs g ( Λ + frac116π GR + controlled higher order terms ) d^dx. Here the volume coefficient includes the sign and normalization written explicitly in the cosmological term in Part I. The expansion must respect the limiting gauge identities and must include an …

    Exact mathematical passage
    
    \Gamma_{\rm eff}[g]
    =
    \int
    \sqrt{\abs g}
    \left(
    \Lambda
    +
    \frac{1}{16\pi G}R
    +
    \text{controlled higher order terms}
    \right)
    \dd^dx.
    
HDefinition passage · 229 passages

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  • Definition passage: Finite quantum seed system · Read passage · 01_finite_core.tex, line 42

    [Finite quantum seed system] A finite quantum seed system is a tuple Q= ( H, ψ_0, O, R, {P_ℓ,α}, H, τ ), where H is a finite-dimensional Hilbert space, ψ_0∈ H is a nonzero seed, O is the declared operator grammar, R is a collection of algebraic or physical constraints, {P_ℓ,α} is an exact packet system at each refinement level, H=H^* is a Hamiltonian when dynamics are present, and τ specifies the topology used in a later completion.

    Exact mathematical passage
    
    \mathfrak Q=
    \left(
    \cH,
    \psi_0,
    \cO,
    \cR,
    \{P_{\ell,\alpha}\},
    H,
    \tau
    \right),
    
H^*Definition passage · 9 passages

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  • Definition passage: Finite quantum seed system · Read passage · 01_finite_core.tex, line 54

    inition:001 A finite quantum seed system is a tuple Q= ( H, ψ_0, O, R, {P_ℓ,α}, H, τ ), where H is a finite-dimensional Hilbert space, ψ_0∈ H is a nonzero seed, O is the declared operator grammar, R is a collection of algebraic or physical constraints, {P_ℓ,α} is an exact packet system at each refinement level, H=H^* is a Hamiltonian when dynamics are present, and τ specifies the topology used in a later completion.

    Exact mathematical passage
    H=H^*
H_\ellDefinition passage · 8 passages

Search aliases: H_ℓ ell

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  • Definition passage: Finite quantum refinement tower · Read passage · 02_strengthened.tex, line 2348

    [Finite quantum refinement tower] A finite quantum refinement tower consists of Hilbert spaces H_ℓ, isometries R_ℓ: H_ℓ⟶ H_ℓ+1, self adjoint Hamiltonians H_ℓ, packet projectors P_ℓ,a, constraints C_ℓ,r, and positive transfer operators T_ℓ. Exact compatibility means that every declared object intertwines with R_ℓ. Approximate compatibility is recorded by the corresponding operator norm defects.

    Exact mathematical passage
    H_\ell
\HcalDefinition passage · 62 passages

Search aliases: Hcal H mathcal

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  • Definition passage: Finite quantum seed system · Read passage · 02_strengthened.tex, line 89

    [Finite quantum seed system] A finite quantum seed system is a triple ( H, A,S), where H is a finite dimensional Hilbert space, A⊆End( H) is a unital star subalgebra, and S⊆ H is a finite set. Its generated hull is A S = span{Aψ:A∈ A, ψ∈ S}. The seed set is cyclic when A S= H. The quantum seed rank is the least cardinality of a cyclic seed set.

    Exact mathematical passage
    
    (\Hcal,\Acal,S),
    
\Hcal_\ellDefinition passage · 5 passages

Search aliases: Hcal_ℓ H_ℓ Hcal ell mathcal ell

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  • Definition passage: Finite quantum refinement tower · Read passage · 02_strengthened.tex, line 2344

    [Finite quantum refinement tower] A finite quantum refinement tower consists of Hilbert spaces H_ℓ, isometries R_ℓ: H_ℓ⟶ H_ℓ+1, self adjoint Hamiltonians H_ℓ, packet projectors P_ℓ,a, constraints C_ℓ,r, and positive transfer operators T_ℓ. Exact compatibility means that every declared object intertwines with R_ℓ. Approximate compatibility is recorded by the corresponding operator norm defects.

    Exact mathematical passage
    \Hcal_\ell
\Hcal_{\ell+1}Definition passage · 3 passages

Search aliases: Hcal_ℓ+1 H_ℓ+1 Hcal ell mathcal ell

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  • Definition passage: Finite quantum refinement tower · Read passage · 02_strengthened.tex, line 2345

    [Finite quantum refinement tower] A finite quantum refinement tower consists of Hilbert spaces H_ℓ, isometries R_ℓ: H_ℓ⟶ H_ℓ+1, self adjoint Hamiltonians H_ℓ, packet projectors P_ℓ,a, constraints C_ℓ,r, and positive transfer operators T_ℓ. Exact compatibility means that every declared object intertwines with R_ℓ. Approximate compatibility is recorded by the corresponding operator norm defects.

    Exact mathematical passage
    
    R_\ell:\Hcal_\ell\longrightarrow\Hcal_{\ell+1},
    
IDefinition passage · 187 passages

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  • Definition passage: Code compression obstruction · Read passage · 02_strengthened.tex, line 1277

    [Code compression obstruction] Let q_P:End( C)⟶End( C)/( C I_ C) be the quotient map. Define Ob_P(A)=q_P(PAP). Equivalently, one may use the traceless representative o_P(A) = PAP- fracTr(PAP)kP.

    Exact mathematical passage
    
    q_P:\End(\Ccal)\longrightarrow\End(\Ccal)/(\CC I_{\Ccal})
    
I_{\Ccal}Definition passage · 1 passage

Search aliases: I_Ccal I_ C Ccal mathcal

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  • Definition passage: Code compression obstruction · Read passage · 02_strengthened.tex, line 1277

    [Code compression obstruction] Let q_P:End( C)⟶End( C)/( C I_ C) be the quotient map. Define Ob_P(A)=q_P(PAP). Equivalently, one may use the traceless representative o_P(A) = PAP- fracTr(PAP)kP.

    Exact mathematical passage
    
    q_P:\End(\Ccal)\longrightarrow\End(\Ccal)/(\CC I_{\Ccal})
    
\iiDefinition passage · 69 passages

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  • Definition passage: Anomaly free continuum constraint system · Read passage · 02_strengthened.tex, line 2540

    [Anomaly free continuum constraint system] A continuum constraint system consists of a Hilbert space, a common invariant dense domain D, and operators C_a on D. It is anomaly free for prescribed structure coefficients when [C_a,C_b]ψ = i∑_cf_ab^phantomabcC_cψ for every ψ∈ D, and when the associated gauge evolution is defined on the physical quotient or physical subspace.

    Exact mathematical passage
    
    [C_a,C_b]\psi
    =
    \ii\sum_cf_{ab}^{\phantom{ab}c}C_c\psi
    
\infDefinition passage · 2 passages

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  • Definition passage: Approximate Knill Laflamme defect · Read passage · 02_strengthened.tex, line 1423

    [Approximate Knill Laflamme defect] For a finite error family, define the following defect. When the family is empty, assign the maximum the value zero. ε_rm KL = max_a,b inf_c∈ C normPE_a^*E_bP-cP.

    Exact mathematical passage
    
    \varepsilon_{\rm KL}
    =
    \max_{a,b}
    \inf_{c\in\CC}
    \norm{PE_a^*E_bP-cP}.
    
\inf_{c\in\CC}Definition passage · 2 passages

Search aliases: inf_c∈CC inf_c∈ C inf in CC inf in mathbb

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  • Definition passage: Approximate Knill Laflamme defect · Read passage · 02_strengthened.tex, line 1423

    [Approximate Knill Laflamme defect] For a finite error family, define the following defect. When the family is empty, assign the maximum the value zero. ε_rm KL = max_a,b inf_c∈ C normPE_a^*E_bP-cP.

    Exact mathematical passage
    
    \varepsilon_{\rm KL}
    =
    \max_{a,b}
    \inf_{c\in\CC}
    \norm{PE_a^*E_bP-cP}.
    
KDefinition passage · 72 passages

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  • Definition passage: Approximate Knill Laflamme defect · Read passage · 02_strengthened.tex, line 1423

    [Approximate Knill Laflamme defect] For a finite error family, define the following defect. When the family is empty, assign the maximum the value zero. ε_rm KL = max_a,b inf_c∈ C normPE_a^*E_bP-cP.

    Exact mathematical passage
    
    \varepsilon_{\rm KL}
    =
    \max_{a,b}
    \inf_{c\in\CC}
    \norm{PE_a^*E_bP-cP}.
    
kDefinition passage · 105 passages

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  • Definition passage: Code compression obstruction · Read passage · 02_strengthened.tex, line 1285

    [Code compression obstruction] Let q_P:End( C)⟶End( C)/( C I_ C) be the quotient map. Define Ob_P(A)=q_P(PAP). Equivalently, one may use the traceless representative o_P(A) = PAP- fracTr(PAP)kP.

    Exact mathematical passage
    
    \ob_P(A)
    =
    PAP-
    \frac{\Tr(PAP)}{k}P.
    
LDefinition passage · 44 passages

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  • Definition passage: Approximate Knill Laflamme defect · Read passage · 02_strengthened.tex, line 1423

    [Approximate Knill Laflamme defect] For a finite error family, define the following defect. When the family is empty, assign the maximum the value zero. ε_rm KL = max_a,b inf_c∈ C normPE_a^*E_bP-cP.

    Exact mathematical passage
    
    \varepsilon_{\rm KL}
    =
    \max_{a,b}
    \inf_{c\in\CC}
    \norm{PE_a^*E_bP-cP}.
    
lDefinition passage · 9 passages

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  • Definition passage: Universal closure obstruction · Read passage · 02_strengthened.tex, line 2186

    [Universal closure obstruction] Let q_ c:End( H)⟶End( H)/ c be the quotient map. Define Ob_ab^rm cl = q_ c([C_a,C_b]).

    Exact mathematical passage
    
    \Ob_{ab}^{\rm cl}
    =
    q_{\mathfrak c}([C_a,C_b]).
    
\logDefinition passage · 12 passages

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  • Definition passage: Heat trace and spectral dimension · Read passage · 02_strengthened.tex, line 1961

    [Heat trace and spectral dimension] Let the eigenvalues of L be λ_1,…,λ_N, with at least one zero eigenvalue. Define Z_L(t)=Tr( e^-tL) and d_L(t) =-2frac dlog Z_L(t) dlog t = 2t fracTr(L e^-tL)Tr( e^-tL).

    Exact mathematical passage
    
    d_L(t)
    =-2\frac{\dd\log Z_L(t)}{\dd\log t}
    =
    2t
    \frac{\Tr(L\e^{-tL})}{\Tr(\e^{-tL})}.
    
\maxDefinition passage · 7 passages

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  • Definition passage: Approximate Knill Laflamme defect · Read passage · 02_strengthened.tex, line 1423

    [Approximate Knill Laflamme defect] For a finite error family, define the following defect. When the family is empty, assign the maximum the value zero. ε_rm KL = max_a,b inf_c∈ C normPE_a^*E_bP-cP.

    Exact mathematical passage
    
    \varepsilon_{\rm KL}
    =
    \max_{a,b}
    \inf_{c\in\CC}
    \norm{PE_a^*E_bP-cP}.
    
\max_{a,b}Definition passage · 1 passage

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  • Definition passage: Approximate Knill Laflamme defect · Read passage · 02_strengthened.tex, line 1423

    [Approximate Knill Laflamme defect] For a finite error family, define the following defect. When the family is empty, assign the maximum the value zero. ε_rm KL = max_a,b inf_c∈ C normPE_a^*E_bP-cP.

    Exact mathematical passage
    
    \varepsilon_{\rm KL}
    =
    \max_{a,b}
    \inf_{c\in\CC}
    \norm{PE_a^*E_bP-cP}.
    
NDefinition passage · 85 passages

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  • Definition passage: Operator charge · Read passage · 02_strengthened.tex, line 294

    [Operator charge] An operator A∈End( H) has cyclic charge q∈ Z/N Z when SAS^*=ω^qA.

    Exact mathematical passage
    q\in\ZZ/N\ZZ
\normDefinition passage · 45 passages

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  • Definition passage: Approximate Knill Laflamme defect · Read passage · 02_strengthened.tex, line 1423

    [Approximate Knill Laflamme defect] For a finite error family, define the following defect. When the family is empty, assign the maximum the value zero. ε_rm KL = max_a,b inf_c∈ C normPE_a^*E_bP-cP.

    Exact mathematical passage
    
    \varepsilon_{\rm KL}
    =
    \max_{a,b}
    \inf_{c\in\CC}
    \norm{PE_a^*E_bP-cP}.
    
\ObDefinition passage · 4 passages

Search aliases: Ob operatorname

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  • Definition passage: Code compression obstruction · Read passage · 02_strengthened.tex, line 1281

    [Code compression obstruction] Let q_P:End( C)⟶End( C)/( C I_ C) be the quotient map. Define Ob_P(A)=q_P(PAP). Equivalently, one may use the traceless representative o_P(A) = PAP- fracTr(PAP)kP.

    Exact mathematical passage
    
    \Ob_P(A)=q_P(PAP).
    
\obDefinition passage · 1 passage

Search aliases: ob o mathfrak

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  • Definition passage: Code compression obstruction · Read passage · 02_strengthened.tex, line 1285

    [Code compression obstruction] Let q_P:End( C)⟶End( C)/( C I_ C) be the quotient map. Define Ob_P(A)=q_P(PAP). Equivalently, one may use the traceless representative o_P(A) = PAP- fracTr(PAP)kP.

    Exact mathematical passage
    
    \ob_P(A)
    =
    PAP-
    \frac{\Tr(PAP)}{k}P.
    
\Ob_{ab}^{\rm cl}Definition passage · 2 passages

Search aliases: Ob_ab^rm cl Ob rm operatorname rm

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  • Definition passage: Universal closure obstruction · Read passage · 02_strengthened.tex, line 2186

    [Universal closure obstruction] Let q_ c:End( H)⟶End( H)/ c be the quotient map. Define Ob_ab^rm cl = q_ c([C_a,C_b]).

    Exact mathematical passage
    
    \Ob_{ab}^{\rm cl}
    =
    q_{\mathfrak c}([C_a,C_b]).
    
\Ob_PDefinition passage · 2 passages

Search aliases: Ob_P Ob operatorname

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  • Definition passage: Code compression obstruction · Read passage · 02_strengthened.tex, line 1281

    [Code compression obstruction] Let q_P:End( C)⟶End( C)/( C I_ C) be the quotient map. Define Ob_P(A)=q_P(PAP). Equivalently, one may use the traceless representative o_P(A) = PAP- fracTr(PAP)kP.

    Exact mathematical passage
    
    \Ob_P(A)=q_P(PAP).
    
\ob_PDefinition passage · 1 passage

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  • Definition passage: Code compression obstruction · Read passage · 02_strengthened.tex, line 1285

    [Code compression obstruction] Let q_P:End( C)⟶End( C)/( C I_ C) be the quotient map. Define Ob_P(A)=q_P(PAP). Equivalently, one may use the traceless representative o_P(A) = PAP- fracTr(PAP)kP.

    Exact mathematical passage
    
    \ob_P(A)
    =
    PAP-
    \frac{\Tr(PAP)}{k}P.
    
PDefinition passage · 512 passages

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  • Definition passage: Finite quantum seed system · Read passage · 01_finite_core.tex, line 42

    [Finite quantum seed system] A finite quantum seed system is a tuple Q= ( H, ψ_0, O, R, {P_ℓ,α}, H, τ ), where H is a finite-dimensional Hilbert space, ψ_0∈ H is a nonzero seed, O is the declared operator grammar, R is a collection of algebraic or physical constraints, {P_ℓ,α} is an exact packet system at each refinement level, H=H^* is a Hamiltonian when dynamics are present, and τ specifies the topology used in a later completion.

    Exact mathematical passage
    
    \mathfrak Q=
    \left(
    \cH,
    \psi_0,
    \cO,
    \cR,
    \{P_{\ell,\alpha}\},
    H,
    \tau
    \right),
    
P_aDefinition passage · 97 passages

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  • Definition passage: Two sided operator packet · Read passage · 02_strengthened.tex, line 944

    [Two sided operator packet] For a complete orthogonal family (P_a), define P_ab(X)=P_aXP_b. The range B_ab=P_aEnd( H)P_b is the operator packet with output address a and input address b.

    Exact mathematical passage
    (P_a)
P_bDefinition passage · 47 passages

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  • Definition passage: Two sided operator packet · Read passage · 02_strengthened.tex, line 945

    [Two sided operator packet] For a complete orthogonal family (P_a), define P_ab(X)=P_aXP_b. The range B_ab=P_aEnd( H)P_b is the operator packet with output address a and input address b.

    Exact mathematical passage
    
    \Pcal_{ab}(X)=P_aXP_b.
    
P_{\ell,a}Definition passage · 3 passages

Search aliases: P_ℓ,a ell

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  • Definition passage: Finite quantum refinement tower · Read passage · 02_strengthened.tex, line 2348

    [Finite quantum refinement tower] A finite quantum refinement tower consists of Hilbert spaces H_ℓ, isometries R_ℓ: H_ℓ⟶ H_ℓ+1, self adjoint Hamiltonians H_ℓ, packet projectors P_ℓ,a, constraints C_ℓ,r, and positive transfer operators T_ℓ. Exact compatibility means that every declared object intertwines with R_ℓ. Approximate compatibility is recorded by the corresponding operator norm defects.

    Exact mathematical passage
    P_{\ell,a}
P_{\ell,\alpha}Definition passage · 4 passages

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  • Definition passage: Finite quantum seed system · Read passage · 01_finite_core.tex, line 42

    [Finite quantum seed system] A finite quantum seed system is a tuple Q= ( H, ψ_0, O, R, {P_ℓ,α}, H, τ ), where H is a finite-dimensional Hilbert space, ψ_0∈ H is a nonzero seed, O is the declared operator grammar, R is a collection of algebraic or physical constraints, {P_ℓ,α} is an exact packet system at each refinement level, H=H^* is a Hamiltonian when dynamics are present, and τ specifies the topology used in a later completion.

    Exact mathematical passage
    
    \mathfrak Q=
    \left(
    \cH,
    \psi_0,
    \cO,
    \cR,
    \{P_{\ell,\alpha}\},
    H,
    \tau
    \right),
    
\PcalDefinition passage · 20 passages

Search aliases: Pcal P mathcal

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  • Definition passage: Two sided operator packet · Read passage · 02_strengthened.tex, line 945

    [Two sided operator packet] For a complete orthogonal family (P_a), define P_ab(X)=P_aXP_b. The range B_ab=P_aEnd( H)P_b is the operator packet with output address a and input address b.

    Exact mathematical passage
    
    \Pcal_{ab}(X)=P_aXP_b.
    
\Pcal_{ab}Definition passage · 4 passages

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  • Definition passage: Two sided operator packet · Read passage · 02_strengthened.tex, line 945

    [Two sided operator packet] For a complete orthogonal family (P_a), define P_ab(X)=P_aXP_b. The range B_ab=P_aEnd( H)P_b is the operator packet with output address a and input address b.

    Exact mathematical passage
    
    \Pcal_{ab}(X)=P_aXP_b.
    
\mathfrak QDefinition passage · 2 passages

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  • Definition passage: Finite quantum seed system · Read passage · 01_finite_core.tex, line 42

    [Finite quantum seed system] A finite quantum seed system is a tuple Q= ( H, ψ_0, O, R, {P_ℓ,α}, H, τ ), where H is a finite-dimensional Hilbert space, ψ_0∈ H is a nonzero seed, O is the declared operator grammar, R is a collection of algebraic or physical constraints, {P_ℓ,α} is an exact packet system at each refinement level, H=H^* is a Hamiltonian when dynamics are present, and τ specifies the topology used in a later completion.

    Exact mathematical passage
    
    \mathfrak Q=
    \left(
    \cH,
    \psi_0,
    \cO,
    \cR,
    \{P_{\ell,\alpha}\},
    H,
    \tau
    \right),
    
qDefinition passage · 52 passages

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  • Definition passage: Operator charge · Read passage · 02_strengthened.tex, line 294

    [Operator charge] An operator A∈End( H) has cyclic charge q∈ Z/N Z when SAS^*=ω^qA.

    Exact mathematical passage
    q\in\ZZ/N\ZZ
q_{\mathfrak c}Definition passage · 2 passages

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  • Definition passage: Universal closure obstruction · Read passage · 02_strengthened.tex, line 2182

    [Universal closure obstruction] Let q_ c:End( H)⟶End( H)/ c be the quotient map. Define Ob_ab^rm cl = q_ c([C_a,C_b]).

    Exact mathematical passage
    
    q_{\mathfrak c}:\End(\Hcal)\longrightarrow\End(\Hcal)/\mathfrak c
    
q_PDefinition passage · 2 passages

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  • Definition passage: Code compression obstruction · Read passage · 02_strengthened.tex, line 1277

    [Code compression obstruction] Let q_P:End( C)⟶End( C)/( C I_ C) be the quotient map. Define Ob_P(A)=q_P(PAP). Equivalently, one may use the traceless representative o_P(A) = PAP- fracTr(PAP)kP.

    Exact mathematical passage
    
    q_P:\End(\Ccal)\longrightarrow\End(\Ccal)/(\CC I_{\Ccal})
    
RDefinition passage · 57 passages

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  • Definition passage: Finite quantum refinement tower · Read passage · 02_strengthened.tex, line 2345

    [Finite quantum refinement tower] A finite quantum refinement tower consists of Hilbert spaces H_ℓ, isometries R_ℓ: H_ℓ⟶ H_ℓ+1, self adjoint Hamiltonians H_ℓ, packet projectors P_ℓ,a, constraints C_ℓ,r, and positive transfer operators T_ℓ. Exact compatibility means that every declared object intertwines with R_ℓ. Approximate compatibility is recorded by the corresponding operator norm defects.

    Exact mathematical passage
    
    R_\ell:\Hcal_\ell\longrightarrow\Hcal_{\ell+1},
    
rDefinition passage · 127 passages

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  • Definition passage: Finite quantum refinement tower · Read passage · 02_strengthened.tex, line 2348

    [Finite quantum refinement tower] A finite quantum refinement tower consists of Hilbert spaces H_ℓ, isometries R_ℓ: H_ℓ⟶ H_ℓ+1, self adjoint Hamiltonians H_ℓ, packet projectors P_ℓ,a, constraints C_ℓ,r, and positive transfer operators T_ℓ. Exact compatibility means that every declared object intertwines with R_ℓ. Approximate compatibility is recorded by the corresponding operator norm defects.

    Exact mathematical passage
    C_{\ell,r}
R_\ellDefinition passage · 13 passages

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  • Definition passage: Finite quantum refinement tower · Read passage · 02_strengthened.tex, line 2345

    [Finite quantum refinement tower] A finite quantum refinement tower consists of Hilbert spaces H_ℓ, isometries R_ℓ: H_ℓ⟶ H_ℓ+1, self adjoint Hamiltonians H_ℓ, packet projectors P_ℓ,a, constraints C_ℓ,r, and positive transfer operators T_ℓ. Exact compatibility means that every declared object intertwines with R_ℓ. Approximate compatibility is recorded by the corresponding operator norm defects.

    Exact mathematical passage
    
    R_\ell:\Hcal_\ell\longrightarrow\Hcal_{\ell+1},
    
\rmDefinition passage · 39 passages

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  • Definition passage: Approximate Knill Laflamme defect · Read passage · 02_strengthened.tex, line 1423

    [Approximate Knill Laflamme defect] For a finite error family, define the following defect. When the family is empty, assign the maximum the value zero. ε_rm KL = max_a,b inf_c∈ C normPE_a^*E_bP-cP.

    Exact mathematical passage
    
    \varepsilon_{\rm KL}
    =
    \max_{a,b}
    \inf_{c\in\CC}
    \norm{PE_a^*E_bP-cP}.
    
SDefinition passage · 88 passages

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  • Definition passage: Finite quantum seed system · Read passage · 02_strengthened.tex, line 89

    [Finite quantum seed system] A finite quantum seed system is a triple ( H, A,S), where H is a finite dimensional Hilbert space, A⊆End( H) is a unital star subalgebra, and S⊆ H is a finite set. Its generated hull is A S = span{Aψ:A∈ A, ψ∈ S}. The seed set is cyclic when A S= H. The quantum seed rank is the least cardinality of a cyclic seed set.

    Exact mathematical passage
    
    (\Hcal,\Acal,S),
    
S^*Definition passage · 19 passages

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  • Definition passage: Operator charge · Read passage · 02_strengthened.tex, line 295

    [Operator charge] An operator A∈End( H) has cyclic charge q∈ Z/N Z when SAS^*=ω^qA.

    Exact mathematical passage
    
    SAS^*=\omega^qA.
    
\operatorname{span}Definition passage · 7 passages

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  • Definition passage: Finite quantum seed system · Read passage · 02_strengthened.tex, line 93

    [Finite quantum seed system] A finite quantum seed system is a triple ( H, A,S), where H is a finite dimensional Hilbert space, A⊆End( H) is a unital star subalgebra, and S⊆ H is a finite set. Its generated hull is A S = span{Aψ:A∈ A, ψ∈ S}. The seed set is cyclic when A S= H. The quantum seed rank is the least cardinality of a cyclic seed set.

    Exact mathematical passage
    
    \Acal S
    =
    \operatorname{span}\{A\psi:A\in\Acal,\ \psi\in S\}.
    
\SpecDefinition passage · 14 passages

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  • Definition passage: Feshbach map and self energy · Read passage · 02_strengthened.tex, line 1501

    [Feshbach map and self energy] For z∉Spec D, define Σ(z)=B(z-D)^-1B^* and F_P(z)=z-A-Σ(z).

    Exact mathematical passage
    z\notin\Spec D
TDefinition passage · 92 passages

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  • Definition passage: Finite quantum refinement tower · Read passage · 02_strengthened.tex, line 2348

    [Finite quantum refinement tower] A finite quantum refinement tower consists of Hilbert spaces H_ℓ, isometries R_ℓ: H_ℓ⟶ H_ℓ+1, self adjoint Hamiltonians H_ℓ, packet projectors P_ℓ,a, constraints C_ℓ,r, and positive transfer operators T_ℓ. Exact compatibility means that every declared object intertwines with R_ℓ. Approximate compatibility is recorded by the corresponding operator norm defects.

    Exact mathematical passage
    T_\ell
tDefinition passage · 229 passages

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  • Definition passage: Heat trace and spectral dimension · Read passage · 02_strengthened.tex, line 1957

    [Heat trace and spectral dimension] Let the eigenvalues of L be λ_1,…,λ_N, with at least one zero eigenvalue. Define Z_L(t)=Tr( e^-tL) and d_L(t) =-2frac dlog Z_L(t) dlog t = 2t fracTr(L e^-tL)Tr( e^-tL).

    Exact mathematical passage
    
    Z_L(t)=\Tr(\e^{-tL})
    
T_\ellDefinition passage · 2 passages

Search aliases: T_ℓ ell

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  • Definition passage: Finite quantum refinement tower · Read passage · 02_strengthened.tex, line 2348

    [Finite quantum refinement tower] A finite quantum refinement tower consists of Hilbert spaces H_ℓ, isometries R_ℓ: H_ℓ⟶ H_ℓ+1, self adjoint Hamiltonians H_ℓ, packet projectors P_ℓ,a, constraints C_ℓ,r, and positive transfer operators T_ℓ. Exact compatibility means that every declared object intertwines with R_ℓ. Approximate compatibility is recorded by the corresponding operator norm defects.

    Exact mathematical passage
    T_\ell
\TrDefinition passage · 37 passages

Search aliases: Tr operatorname

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  • Definition passage: Code compression obstruction · Read passage · 02_strengthened.tex, line 1285

    [Code compression obstruction] Let q_P:End( C)⟶End( C)/( C I_ C) be the quotient map. Define Ob_P(A)=q_P(PAP). Equivalently, one may use the traceless representative o_P(A) = PAP- fracTr(PAP)kP.

    Exact mathematical passage
    
    \ob_P(A)
    =
    PAP-
    \frac{\Tr(PAP)}{k}P.
    
XDefinition passage · 125 passages

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  • Definition passage: Two sided operator packet · Read passage · 02_strengthened.tex, line 945

    [Two sided operator packet] For a complete orthogonal family (P_a), define P_ab(X)=P_aXP_b. The range B_ab=P_aEnd( H)P_b is the operator packet with output address a and input address b.

    Exact mathematical passage
    
    \Pcal_{ab}(X)=P_aXP_b.
    
xDefinition passage · 106 passages

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  • Definition passage: Einstein infrared criterion · Read passage · 02_strengthened.tex, line 2558

    [Einstein infrared criterion] A quantum geometric tower meets an Einstein infrared criterion only if an effective action is controlled at long wavelengths and has an expansion whose leading geometric terms take the form Γ_rm eff[g] = ∫ sqrtabs g ( Λ + frac116π GR + controlled higher order terms ) d^dx. Here the volume coefficient includes the sign and normalization written explicitly in the cosmological term in Part I. The expansion must respect the limiting gauge identities and must include an …

    Exact mathematical passage
    
    \Gamma_{\rm eff}[g]
    =
    \int
    \sqrt{\abs g}
    \left(
    \Lambda
    +
    \frac{1}{16\pi G}R
    +
    \text{controlled higher order terms}
    \right)
    \dd^dx.
    
ZDefinition passage · 41 passages

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  • Definition passage: Heat trace and spectral dimension · Read passage · 02_strengthened.tex, line 1957

    [Heat trace and spectral dimension] Let the eigenvalues of L be λ_1,…,λ_N, with at least one zero eigenvalue. Define Z_L(t)=Tr( e^-tL) and d_L(t) =-2frac dlog Z_L(t) dlog t = 2t fracTr(L e^-tL)Tr( e^-tL).

    Exact mathematical passage
    
    Z_L(t)=\Tr(\e^{-tL})
    
zDefinition passage · 100 passages

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  • Definition passage: Feshbach map and self energy · Read passage · 02_strengthened.tex, line 1501

    [Feshbach map and self energy] For z∉Spec D, define Σ(z)=B(z-D)^-1B^* and F_P(z)=z-A-Σ(z).

    Exact mathematical passage
    z\notin\Spec D
Z_LDefinition passage · 4 passages

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  • Definition passage: Heat trace and spectral dimension · Read passage · 02_strengthened.tex, line 1957

    [Heat trace and spectral dimension] Let the eigenvalues of L be λ_1,…,λ_N, with at least one zero eigenvalue. Define Z_L(t)=Tr( e^-tL) and d_L(t) =-2frac dlog Z_L(t) dlog t = 2t fracTr(L e^-tL)Tr( e^-tL).

    Exact mathematical passage
    
    Z_L(t)=\Tr(\e^{-tL})
    
\ZZDefinition passage · 11 passages

Search aliases: ZZ Z mathbb

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  • Definition passage: Operator charge · Read passage · 02_strengthened.tex, line 294

    [Operator charge] An operator A∈End( H) has cyclic charge q∈ Z/N Z when SAS^*=ω^qA.

    Exact mathematical passage
    q\in\ZZ/N\ZZ
\alphaDefinition passage · 25 passages

Search aliases: α alpha

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  • Definition passage: Finite quantum seed system · Read passage · 01_finite_core.tex, line 42

    [Finite quantum seed system] A finite quantum seed system is a tuple Q= ( H, ψ_0, O, R, {P_ℓ,α}, H, τ ), where H is a finite-dimensional Hilbert space, ψ_0∈ H is a nonzero seed, O is the declared operator grammar, R is a collection of algebraic or physical constraints, {P_ℓ,α} is an exact packet system at each refinement level, H=H^* is a Hamiltonian when dynamics are present, and τ specifies the topology used in a later completion.

    Exact mathematical passage
    
    \mathfrak Q=
    \left(
    \cH,
    \psi_0,
    \cO,
    \cR,
    \{P_{\ell,\alpha}\},
    H,
    \tau
    \right),
    
\GammaDefinition passage · 5 passages

Search aliases: Γ Gamma

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  • Definition passage: Einstein infrared criterion · Read passage · 02_strengthened.tex, line 2558

    [Einstein infrared criterion] A quantum geometric tower meets an Einstein infrared criterion only if an effective action is controlled at long wavelengths and has an expansion whose leading geometric terms take the form Γ_rm eff[g] = ∫ sqrtabs g ( Λ + frac116π GR + controlled higher order terms ) d^dx. Here the volume coefficient includes the sign and normalization written explicitly in the cosmological term in Part I. The expansion must respect the limiting gauge identities and must include an …

    Exact mathematical passage
    
    \Gamma_{\rm eff}[g]
    =
    \int
    \sqrt{\abs g}
    \left(
    \Lambda
    +
    \frac{1}{16\pi G}R
    +
    \text{controlled higher order terms}
    \right)
    \dd^dx.
    
\Gamma_{\rm eff}Definition passage · 1 passage

Search aliases: Γ_rm eff Gamma rm

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  • Definition passage: Einstein infrared criterion · Read passage · 02_strengthened.tex, line 2558

    [Einstein infrared criterion] A quantum geometric tower meets an Einstein infrared criterion only if an effective action is controlled at long wavelengths and has an expansion whose leading geometric terms take the form Γ_rm eff[g] = ∫ sqrtabs g ( Λ + frac116π GR + controlled higher order terms ) d^dx. Here the volume coefficient includes the sign and normalization written explicitly in the cosmological term in Part I. The expansion must respect the limiting gauge identities and must include an …

    Exact mathematical passage
    
    \Gamma_{\rm eff}[g]
    =
    \int
    \sqrt{\abs g}
    \left(
    \Lambda
    +
    \frac{1}{16\pi G}R
    +
    \text{controlled higher order terms}
    \right)
    \dd^dx.
    
\varepsilonDefinition passage · 33 passages

Search aliases: ε varepsilon

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  • Definition passage: Approximate Knill Laflamme defect · Read passage · 02_strengthened.tex, line 1423

    [Approximate Knill Laflamme defect] For a finite error family, define the following defect. When the family is empty, assign the maximum the value zero. ε_rm KL = max_a,b inf_c∈ C normPE_a^*E_bP-cP.

    Exact mathematical passage
    
    \varepsilon_{\rm KL}
    =
    \max_{a,b}
    \inf_{c\in\CC}
    \norm{PE_a^*E_bP-cP}.
    
\varepsilon_{\rm KL}Definition passage · 4 passages

Search aliases: ε_rm KL varepsilon rm

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  • Definition passage: Approximate Knill Laflamme defect · Read passage · 02_strengthened.tex, line 1423

    [Approximate Knill Laflamme defect] For a finite error family, define the following defect. When the family is empty, assign the maximum the value zero. ε_rm KL = max_a,b inf_c∈ C normPE_a^*E_bP-cP.

    Exact mathematical passage
    
    \varepsilon_{\rm KL}
    =
    \max_{a,b}
    \inf_{c\in\CC}
    \norm{PE_a^*E_bP-cP}.
    
\LambdaDefinition passage · 5 passages

Search aliases: Λ Lambda

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  • Definition passage: Einstein infrared criterion · Read passage · 02_strengthened.tex, line 2558

    [Einstein infrared criterion] A quantum geometric tower meets an Einstein infrared criterion only if an effective action is controlled at long wavelengths and has an expansion whose leading geometric terms take the form Γ_rm eff[g] = ∫ sqrtabs g ( Λ + frac116π GR + controlled higher order terms ) d^dx. Here the volume coefficient includes the sign and normalization written explicitly in the cosmological term in Part I. The expansion must respect the limiting gauge identities and must include an …

    Exact mathematical passage
    
    \Gamma_{\rm eff}[g]
    =
    \int
    \sqrt{\abs g}
    \left(
    \Lambda
    +
    \frac{1}{16\pi G}R
    +
    \text{controlled higher order terms}
    \right)
    \dd^dx.
    
\lambdaDefinition passage · 62 passages

Search aliases: λ lambda

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  • Definition passage: Heat trace and spectral dimension · Read passage · 02_strengthened.tex, line 1956

    [Heat trace and spectral dimension] Let the eigenvalues of L be λ_1,…,λ_N, with at least one zero eigenvalue. Define Z_L(t)=Tr( e^-tL) and d_L(t) =-2frac dlog Z_L(t) dlog t = 2t fracTr(L e^-tL)Tr( e^-tL).

    Exact mathematical passage
    \lambda_1,\ldots,\lambda_N
\lambda_1Definition passage · 2 passages

Search aliases: λ_1 lambda

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  • Definition passage: Heat trace and spectral dimension · Read passage · 02_strengthened.tex, line 1956

    [Heat trace and spectral dimension] Let the eigenvalues of L be λ_1,…,λ_N, with at least one zero eigenvalue. Define Z_L(t)=Tr( e^-tL) and d_L(t) =-2frac dlog Z_L(t) dlog t = 2t fracTr(L e^-tL)Tr( e^-tL).

    Exact mathematical passage
    \lambda_1,\ldots,\lambda_N
\lambda_NDefinition passage · 11 passages

Search aliases: λ_N lambda

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  • Definition passage: Heat trace and spectral dimension · Read passage · 02_strengthened.tex, line 1956

    [Heat trace and spectral dimension] Let the eigenvalues of L be λ_1,…,λ_N, with at least one zero eigenvalue. Define Z_L(t)=Tr( e^-tL) and d_L(t) =-2frac dlog Z_L(t) dlog t = 2t fracTr(L e^-tL)Tr( e^-tL).

    Exact mathematical passage
    \lambda_1,\ldots,\lambda_N
\piDefinition passage · 53 passages

Search aliases: π pi

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  • Definition passage: Einstein infrared criterion · Read passage · 02_strengthened.tex, line 2558

    [Einstein infrared criterion] A quantum geometric tower meets an Einstein infrared criterion only if an effective action is controlled at long wavelengths and has an expansion whose leading geometric terms take the form Γ_rm eff[g] = ∫ sqrtabs g ( Λ + frac116π GR + controlled higher order terms ) d^dx. Here the volume coefficient includes the sign and normalization written explicitly in the cosmological term in Part I. The expansion must respect the limiting gauge identities and must include an …

    Exact mathematical passage
    
    \Gamma_{\rm eff}[g]
    =
    \int
    \sqrt{\abs g}
    \left(
    \Lambda
    +
    \frac{1}{16\pi G}R
    +
    \text{controlled higher order terms}
    \right)
    \dd^dx.
    
\SigmaDefinition passage · 20 passages

Search aliases: Σ Sigma

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  • Definition passage: Feshbach map and self energy · Read passage · 02_strengthened.tex, line 1502

    [Feshbach map and self energy] For z∉Spec D, define Σ(z)=B(z-D)^-1B^* and F_P(z)=z-A-Σ(z).

    Exact mathematical passage
    
    \Sigma(z)=B(z-D)^{-1}B^*
    
\tauDefinition passage · 24 passages

Search aliases: τ tau

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  • Definition passage: Finite quantum seed system · Read passage · 01_finite_core.tex, line 42

    [Finite quantum seed system] A finite quantum seed system is a tuple Q= ( H, ψ_0, O, R, {P_ℓ,α}, H, τ ), where H is a finite-dimensional Hilbert space, ψ_0∈ H is a nonzero seed, O is the declared operator grammar, R is a collection of algebraic or physical constraints, {P_ℓ,α} is an exact packet system at each refinement level, H=H^* is a Hamiltonian when dynamics are present, and τ specifies the topology used in a later completion.

    Exact mathematical passage
    
    \mathfrak Q=
    \left(
    \cH,
    \psi_0,
    \cO,
    \cR,
    \{P_{\ell,\alpha}\},
    H,
    \tau
    \right),
    
\psiDefinition passage · 107 passages

Search aliases: ψ psi

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  • Definition passage: Finite quantum seed system · Read passage · 01_finite_core.tex, line 42

    [Finite quantum seed system] A finite quantum seed system is a tuple Q= ( H, ψ_0, O, R, {P_ℓ,α}, H, τ ), where H is a finite-dimensional Hilbert space, ψ_0∈ H is a nonzero seed, O is the declared operator grammar, R is a collection of algebraic or physical constraints, {P_ℓ,α} is an exact packet system at each refinement level, H=H^* is a Hamiltonian when dynamics are present, and τ specifies the topology used in a later completion.

    Exact mathematical passage
    
    \mathfrak Q=
    \left(
    \cH,
    \psi_0,
    \cO,
    \cR,
    \{P_{\ell,\alpha}\},
    H,
    \tau
    \right),
    
\psi_0Definition passage · 15 passages

Search aliases: ψ_0 psi

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  • Definition passage: Finite quantum seed system · Read passage · 01_finite_core.tex, line 42

    [Finite quantum seed system] A finite quantum seed system is a tuple Q= ( H, ψ_0, O, R, {P_ℓ,α}, H, τ ), where H is a finite-dimensional Hilbert space, ψ_0∈ H is a nonzero seed, O is the declared operator grammar, R is a collection of algebraic or physical constraints, {P_ℓ,α} is an exact packet system at each refinement level, H=H^* is a Hamiltonian when dynamics are present, and τ specifies the topology used in a later completion.

    Exact mathematical passage
    
    \mathfrak Q=
    \left(
    \cH,
    \psi_0,
    \cO,
    \cR,
    \{P_{\ell,\alpha}\},
    H,
    \tau
    \right),
    
\omegaDefinition passage · 21 passages

Search aliases: ω omega

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  • Definition passage: Operator charge · Read passage · 02_strengthened.tex, line 295

    [Operator charge] An operator A∈End( H) has cyclic charge q∈ Z/N Z when SAS^*=ω^qA.

    Exact mathematical passage
    
    SAS^*=\omega^qA.
    
\omega^qDefinition passage · 3 passages

Search aliases: ω^q omega

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  • Definition passage: Operator charge · Read passage · 02_strengthened.tex, line 295

    [Operator charge] An operator A∈End( H) has cyclic charge q∈ Z/N Z when SAS^*=ω^qA.

    Exact mathematical passage
    
    SAS^*=\omega^qA.
    
\ldotsDefinition passage · 31 passages

Search aliases: … ldots

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  • Definition passage: Heat trace and spectral dimension · Read passage · 02_strengthened.tex, line 1956

    [Heat trace and spectral dimension] Let the eigenvalues of L be λ_1,…,λ_N, with at least one zero eigenvalue. Define Z_L(t)=Tr( e^-tL) and d_L(t) =-2frac dlog Z_L(t) dlog t = 2t fracTr(L e^-tL)Tr( e^-tL).

    Exact mathematical passage
    \lambda_1,\ldots,\lambda_N
\ellDefinition passage · 52 passages

Search aliases: ℓ ell

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  • Definition passage: Finite quantum seed system · Read passage · 01_finite_core.tex, line 42

    [Finite quantum seed system] A finite quantum seed system is a tuple Q= ( H, ψ_0, O, R, {P_ℓ,α}, H, τ ), where H is a finite-dimensional Hilbert space, ψ_0∈ H is a nonzero seed, O is the declared operator grammar, R is a collection of algebraic or physical constraints, {P_ℓ,α} is an exact packet system at each refinement level, H=H^* is a Hamiltonian when dynamics are present, and τ specifies the topology used in a later completion.

    Exact mathematical passage
    
    \mathfrak Q=
    \left(
    \cH,
    \psi_0,
    \cO,
    \cR,
    \{P_{\ell,\alpha}\},
    H,
    \tau
    \right),
    
\inDefinition passage · 89 passages

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  • Definition passage: Finite quantum seed system · Read passage · 01_finite_core.tex, line 54

    [Finite quantum seed system] A finite quantum seed system is a tuple Q= ( H, ψ_0, O, R, {P_ℓ,α}, H, τ ), where H is a finite-dimensional Hilbert space, ψ_0∈ H is a nonzero seed, O is the declared operator grammar, R is a collection of algebraic or physical constraints, {P_ℓ,α} is an exact packet system at each refinement level, H=H^* is a Hamiltonian when dynamics are present, and τ specifies the topology used in a later completion.

    Exact mathematical passage
    \psi_0\in\cH
\notinDefinition passage · 3 passages

Search aliases: ∉ notin

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  • Definition passage: Feshbach map and self energy · Read passage · 02_strengthened.tex, line 1501

    [Feshbach map and self energy] For z∉Spec D, define Σ(z)=B(z-D)^-1B^* and F_P(z)=z-A-Σ(z).

    Exact mathematical passage
    z\notin\Spec D
\sumDefinition passage · 187 passages

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  • Definition passage: Packet dephasing · Read passage · 02_strengthened.tex, line 992

    [Packet dephasing] The packet dephasing map is D_ P(X)=∑_aP_aXP_a.

    Exact mathematical passage
    
    \Dcal_{\Pcal}(X)=\sum_aP_aXP_a.
    
\sum_aDefinition passage · 63 passages

Search aliases: ∑_a sum

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  • Definition passage: Packet dephasing · Read passage · 02_strengthened.tex, line 992

    [Packet dephasing] The packet dephasing map is D_ P(X)=∑_aP_aXP_a.

    Exact mathematical passage
    
    \Dcal_{\Pcal}(X)=\sum_aP_aXP_a.
    
\sum_cDefinition passage · 8 passages

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  • Definition passage: Anomaly free continuum constraint system · Read passage · 02_strengthened.tex, line 2540

    [Anomaly free continuum constraint system] A continuum constraint system consists of a Hilbert space, a common invariant dense domain D, and operators C_a on D. It is anomaly free for prescribed structure coefficients when [C_a,C_b]ψ = i∑_cf_ab^phantomabcC_cψ for every ψ∈ D, and when the associated gauge evolution is defined on the physical quotient or physical subspace.

    Exact mathematical passage
    
    [C_a,C_b]\psi
    =
    \ii\sum_cf_{ab}^{\phantom{ab}c}C_c\psi
    
\intDefinition passage · 14 passages

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  • Definition passage: Einstein infrared criterion · Read passage · 02_strengthened.tex, line 2558

    [Einstein infrared criterion] A quantum geometric tower meets an Einstein infrared criterion only if an effective action is controlled at long wavelengths and has an expansion whose leading geometric terms take the form Γ_rm eff[g] = ∫ sqrtabs g ( Λ + frac116π GR + controlled higher order terms ) d^dx. Here the volume coefficient includes the sign and normalization written explicitly in the cosmological term in Part I. The expansion must respect the limiting gauge identities and must include an …

    Exact mathematical passage
    
    \Gamma_{\rm eff}[g]
    =
    \int
    \sqrt{\abs g}
    \left(
    \Lambda
    +
    \frac{1}{16\pi G}R
    +
    \text{controlled higher order terms}
    \right)
    \dd^dx.
    
\subseteqDefinition passage · 6 passages

Search aliases: ⊆ subseteq

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  • Definition passage: Finite quantum seed system · Read passage · 02_strengthened.tex, line 92

    [Finite quantum seed system] A finite quantum seed system is a triple ( H, A,S), where H is a finite dimensional Hilbert space, A⊆End( H) is a unital star subalgebra, and S⊆ H is a finite set. Its generated hull is A S = span{Aψ:A∈ A, ψ∈ S}. The seed set is cyclic when A S= H. The quantum seed rank is the least cardinality of a cyclic seed set.

    Exact mathematical passage
    \Acal\subseteq\End(\Hcal)
\longrightarrowDefinition passage · 23 passages

Search aliases: ⟶ longrightarrow

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  • Definition passage: Code compression obstruction · Read passage · 02_strengthened.tex, line 1277

    [Code compression obstruction] Let q_P:End( C)⟶End( C)/( C I_ C) be the quotient map. Define Ob_P(A)=q_P(PAP). Equivalently, one may use the traceless representative o_P(A) = PAP- fracTr(PAP)kP.

    Exact mathematical passage
    
    q_P:\End(\Ccal)\longrightarrow\End(\Ccal)/(\CC I_{\Ccal})
    
\mathcal AIntroduction passage · 5 passages

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  • Introduction passage · Read passage · 03_supplement_03.tex, line 31

    Simultaneous generation in a direct sum. For the stipulated block representation A=⊕_i(M_d_i( C)⊗ I_m_i), d_i>0, the proof establishes that k seeds generate all blocks simultaneously exactly when m_i≤ kd_i for every i. It follows that srank_ A( H)=max_ilceilfracm_id_irceil. The final Lean proposition is an codeIsLeast statement over the set of feasible seed counts. It proves both attainment and minimality. For an empty block family the finite supremum is defined as 0, matching the zero module.

    Exact mathematical passage
    
    \mathcal A=\bigoplus_i\bigl(M_{d_i}(\C)\otimes I_{m_i}\bigr),\qquad d_i>0,
    
A^*Introduction passage · 4 passages

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  • Introduction passage · monograph_atlas.tex, line 20

    vpage2The objects on the pageAN ATLAS OF TYPES AND CONVENTIONSTraditional edition: Definition II.2.1, Definition II.7.1. The same letter can stand for different kinds of data in different calculations. Keep the following types fixed while reading a formula. In this appendix, vectors are columns, operators compose from right to left, and A^* denotes the conjugate transpose. linewidth@p.13linewidthYY@ Symbol · Object · What it records

    Exact mathematical passage
    A^*
A_+Introduction passage · 4 passages

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  • Introduction passage · Read passage · 03_supplement_05.tex, line 71

    A channel on the whole ambient space. Put Q=I-∑_r∈ A_+V_rV_r^*. The recovery is R(σ)=∑_r∈ A_+V_r^*σ V_r+Qσ Q. The complement is an orthogonal projector and ∑_r∈ A_+V_rV_r^*+Q^*Q=I. Hence the recovery is trace preserving. Its finite Kraus form also proves positivity after amplification by the identity on every finite auxiliary space. The complement term matters: the map is defined as a channel even outside the syndrome ranges.

    Exact mathematical passage
    Q=I-\sum_{r\in A_+}V_rV_r^*
a_1Introduction passage · 11 passages

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  • Introduction passage · Read passage · 01_finite_core.tex, line 161

    [One seed for the computational basis] For an integer n≥0, let ψ_0=ket0^⊗ n and let X_j denote the Pauli X operator on qubit j. Then { X_1^a_1⋯ X_n^a_nψ_0: (a_1,…,a_n)∈{0,1}^n } is the complete computational basis. Hence the seed is cyclic under the algebra generated by the X_j.

    Exact mathematical passage
    
    \left\{
    X_1^{a_1}\cdots X_n^{a_n}\psi_0:
    (a_1,\ldots,a_n)\in\{0,1\}^n
    \right\}
    
A_aIntroduction passage · 5 passages

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  • Introduction passage · Read passage · 03_supplement_06.tex, line 38

    The mutually inverse local maps. Write T_a(x)=T(P(x),P(a)). For x∈ U_a, B_a(x): E_a⟶ E_x, v⟼ T_a(x)v, A_a(x): E_x⟶ E_a, w⟼ P(a)T_a(x)^-1w. The intertwining identity and its inverse counterpart show that the displayed targets are correct. Lean proves both inverse laws, continuity, linearity in the fiber and smooth dependence on the base. Thus E|_U_a ≅ U_a× E_a is a local product homeomorphism that preserves the base point.

    Exact mathematical passage
    
    A_a(x):\mathcal E_x\longrightarrow\mathcal E_a,
    \quad w\longmapsto P(a)T_a(x)^{-1}w.
    
a_nIntroduction passage · 5 passages

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  • Introduction passage · Read passage · 01_finite_core.tex, line 161

    [One seed for the computational basis] For an integer n≥0, let ψ_0=ket0^⊗ n and let X_j denote the Pauli X operator on qubit j. Then { X_1^a_1⋯ X_n^a_nψ_0: (a_1,…,a_n)∈{0,1}^n } is the complete computational basis. Hence the seed is cyclic under the algebra generated by the X_j.

    Exact mathematical passage
    
    \left\{
    X_1^{a_1}\cdots X_n^{a_n}\psi_0:
    (a_1,\ldots,a_n)\in\{0,1\}^n
    \right\}
    
B_aIntroduction passage · 3 passages

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  • Introduction passage · Read passage · 03_supplement_06.tex, line 34

    The mutually inverse local maps. Write T_a(x)=T(P(x),P(a)). For x∈ U_a, B_a(x): E_a⟶ E_x, v⟼ T_a(x)v, A_a(x): E_x⟶ E_a, w⟼ P(a)T_a(x)^-1w. The intertwining identity and its inverse counterpart show that the displayed targets are correct. Lean proves both inverse laws, continuity, linearity in the fiber and smooth dependence on the base. Thus E|_U_a ≅ U_a× E_a is a local product homeomorphism that preserves the base point.

    Exact mathematical passage
    
    B_a(x):\mathcal E_a\longrightarrow\mathcal E_x,
    \quad v\longmapsto T_a(x)v,
    
\CIntroduction passage · 10 passages

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  • Introduction passage · Read passage · 03_supplement_03.tex, line 31

    Simultaneous generation in a direct sum. For the stipulated block representation A=⊕_i(M_d_i( C)⊗ I_m_i), d_i>0, the proof establishes that k seeds generate all blocks simultaneously exactly when m_i≤ kd_i for every i. It follows that srank_ A( H)=max_ilceilfracm_id_irceil. The final Lean proposition is an codeIsLeast statement over the set of feasible seed counts. It proves both attainment and minimality. For an empty block family the finite supremum is defined as 0, matching the zero module.

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    \mathcal A=\bigoplus_i\bigl(M_{d_i}(\C)\otimes I_{m_i}\bigr),\qquad d_i>0,
    
C^{\mathsf T}Introduction passage · 1 passage

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  • Introduction passage · Read passage · 03_supplement_03.tex, line 74

    The actual partial trace and its support. The reduced matrix is defined by tracing the addressed index of the density matrix of the pure state: (ρ_B)_jℓ=∑_iψ_ijoverlineψ_iℓ. For the coefficient convention used here, the exact Gram identity is ρ_B=C^ T(C^ T)^*, rankρ_B=rank C=r(ψ). The transpose is important. With this convention, writing C^*C instead would conjugate the reduced matrix. The Lean source checks the entrywise identity and positivity of the resulting matrix.

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    \rho_B=C^{\mathsf T}(C^{\mathsf T})^*,
    \qquad \rank\rho_B=\rank C=r(\psi).
    
C^*Introduction passage · 5 passages

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  • Introduction passage · Read passage · 03_supplement_03.tex, line 78

    al trace and its support The reduced matrix is defined by tracing the addressed index of the density matrix of the pure state: (ρ_B)_jℓ=∑_iψ_ijoverlineψ_iℓ. For the coefficient convention used here, the exact Gram identity is ρ_B=C^ T(C^ T)^*, rankρ_B=rank C=r(ψ). The transpose is important. With this convention, writing C^*C instead would conjugate the reduced matrix. The Lean source checks the entrywise identity and positivity of the resulting matrix.

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    C^*C
\CC^2Introduction passage · 10 passages

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  • Introduction passage · monograph_atlas.tex, line 712

    al values. At integer time n≥0, T^n=diag(1,2^-n,4^-n), P_0=diag(1,0,0), normT^n-P_0=2^-n. The gap Δ=log2 determines the rate e^-nΔ exactly in this example. xfigtransfer_ground headStrict positivity is an essential finite hypothesis For T'=diag(1,0), the operator is positive semidefinite, but there is no finite self-adjoint H' on all of C^2 with T'=e^-H': every finite eigenvalue of H' exponentiates to a strictly positive value. One may restrict to the positive support, but that changes the space …

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    \CC^2
\operatorname{CNOT}Introduction passage · 1 passage

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  • Introduction passage · Read passage · 01_finite_core.tex, line 337

    [Bell seed circuit] In this example only, H denotes the Hadamard gate, not a Hamiltonian. Starting from ket00, (H⊗ I)ket00 = fracket00+ket10sqrt2, and then CNOT(H⊗ I)ket00 = fracket00+ket11sqrt2. The parity packets show that the final state lies entirely in the even sector, while the intermediate circuit path passes through both even and odd addresses.

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    \operatorname{CNOT}(H\otimes I)\ket{00}
    =
    \frac{\ket{00}+\ket{11}}{\sqrt2}.
    
D_{[X,Y]}Introduction passage · 1 passage

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  • Introduction passage · Read passage · 01_finite_core.tex, line 617

    textitCurvature. Differentiating P^2=P gives P(dP(X))P=0. Write D_Xs=ds(X). For ambient smooth sections, D_XD_Ys-D_YD_Xs-D_[X,Y]s=0. Expansion of the projected derivatives therefore leaves R(X,Y)s=P(dP(X))D_Ys-P(dP(Y))D_Xs. Since Ps=s, differentiation gives D_Ys=(dP(Y))s+PD_Ys. The terms with a middle P vanish. Thus R(X,Y)s=P(dP(X)dP(Y)-dP(Y)dP(X))P s. This expression is alternating and bilinear in the tangent vectors, and it preserves the range. The ordinary chain rule and the transformation la…

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    D_XD_Ys-D_YD_Xs-D_{[X,Y]}s=0.
    
d_iIntroduction passage · 16 passages

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  • Introduction passage · Read passage · 03_supplement_03.tex, line 31

    Simultaneous generation in a direct sum. For the stipulated block representation A=⊕_i(M_d_i( C)⊗ I_m_i), d_i>0, the proof establishes that k seeds generate all blocks simultaneously exactly when m_i≤ kd_i for every i. It follows that srank_ A( H)=max_ilceilfracm_id_irceil. The final Lean proposition is an codeIsLeast statement over the set of feasible seed counts. It proves both attainment and minimality. For an empty block family the finite supremum is defined as 0, matching the zero module.

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    \mathcal A=\bigoplus_i\bigl(M_{d_i}(\C)\otimes I_{m_i}\bigr),\qquad d_i>0,
    
D_MIntroduction passage · 4 passages

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  • Introduction passage · Read passage · 03_supplement_06.tex, line 61

    A connection on the constructed bundle. The global formula is defined using the actual manifold derivative: ∇_Xs(x)=P(x) D_Ms(x)[X(x)]. Here D_M is represented by pathmvfderiv. A second definition, pathGlobalConnection.covariant, has values in the actual fiber: ∇ s(x):T_xM⟶ E_x. It is not only an ambient expression asserted to land in the range.

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    \nabla_Xs(x)=P(x)\,D_Ms(x)[X(x)].
    
D_XIntroduction passage · 3 passages

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  • Introduction passage · Read passage · 01_finite_core.tex, line 616

    textitCurvature. Differentiating P^2=P gives P(dP(X))P=0. Write D_Xs=ds(X). For ambient smooth sections, D_XD_Ys-D_YD_Xs-D_[X,Y]s=0. Expansion of the projected derivatives therefore leaves R(X,Y)s=P(dP(X))D_Ys-P(dP(Y))D_Xs. Since Ps=s, differentiation gives D_Ys=(dP(Y))s+PD_Ys. The terms with a middle P vanish. Thus R(X,Y)s=P(dP(X)dP(Y)-dP(Y)dP(X))P s. This expression is alternating and bilinear in the tangent vectors, and it preserves the range. The ordinary chain rule and the transformation la…

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    D_Xs=ds(X)
D_YIntroduction passage · 3 passages

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  • Introduction passage · Read passage · 01_finite_core.tex, line 617

    textitCurvature. Differentiating P^2=P gives P(dP(X))P=0. Write D_Xs=ds(X). For ambient smooth sections, D_XD_Ys-D_YD_Xs-D_[X,Y]s=0. Expansion of the projected derivatives therefore leaves R(X,Y)s=P(dP(X))D_Ys-P(dP(Y))D_Xs. Since Ps=s, differentiation gives D_Ys=(dP(Y))s+PD_Ys. The terms with a middle P vanish. Thus R(X,Y)s=P(dP(X)dP(Y)-dP(Y)dP(X))P s. This expression is alternating and bilinear in the tangent vectors, and it preserves the range. The ordinary chain rule and the transformation la…

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    D_XD_Ys-D_YD_Xs-D_{[X,Y]}s=0.
    
d_\lambdaIntroduction passage · 6 passages

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  • Introduction passage · Read passage · 02_strengthened.tex, line 203

    Let G be a finite group and let U:G⟶ U( H) be a unitary representation. Write widehat G for the set of irreducible unitary representations. For λ∈widehat G, let d_λ and χ_λ denote its dimension and character.

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\diagIntroduction passage · 27 passages

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  • Introduction passage · monograph_atlas.tex, line 705

    ermines its HamiltonianSTRICT POSITIVITY AND THE GROUND GAPTraditional edition: Theorem II.10.2, Proposition II.10.5. On HH= C^3, take the strictly positive contraction T=diag(1,1/2,1/4), H=-log T=diag(0,log2,2log2). At unit Euclidean time, T=e^-H. The self-adjoint logarithm is unique because the logarithm acts on positive spectral values. At integer time n≥0, T^n=diag(1,2^-n,4^-n), P_0=diag(1,0,0), normT^n-P_0=2^-n. The gap Δ=log2 determines the rate e^-nΔ exactly in this example. xfigtransfer_…

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    T^n=\diag(1,2^{-n},4^{-n}),\qquad
    P_0=\diag(1,0,0),\qquad\norm{T^n-P_0}=2^{-n}.
    
\dot UIntroduction passage · 16 passages

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  • Introduction passage · Read passage · 03_supplement_02.tex, line 90

    Fix a real time t and a finite complex coordinate space. Let U(s) be a unitary matrix curve, differentiable entrywise at t, and let ψ(s) be differentiable componentwise at t. Write dot U and dotψ for those derivatives. Suppose idotψ=Hψ(t). Only the value of the Hamiltonian at the chosen time is needed. No derivative of H is assumed.

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\dot\psiIntroduction passage · 4 passages

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  • Introduction passage · Read passage · 03_supplement_02.tex, line 90

    Fix a real time t and a finite complex coordinate space. Let U(s) be a unitary matrix curve, differentiable entrywise at t, and let ψ(s) be differentiable componentwise at t. Write dot U and dotψ for those derivatives. Suppose idotψ=Hψ(t). Only the value of the Hamiltonian at the chosen time is needed. No derivative of H is assumed.

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    \dot\psi
\mathcal EIntroduction passage · 9 passages

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  • Introduction passage · Read passage · 03_supplement_06.tex, line 34

    The mutually inverse local maps. Write T_a(x)=T(P(x),P(a)). For x∈ U_a, B_a(x): E_a⟶ E_x, v⟼ T_a(x)v, A_a(x): E_x⟶ E_a, w⟼ P(a)T_a(x)^-1w. The intertwining identity and its inverse counterpart show that the displayed targets are correct. Lean proves both inverse laws, continuity, linearity in the fiber and smooth dependence on the base. Thus E|_U_a ≅ U_a× E_a is a local product homeomorphism that preserves the base point.

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    B_a(x):\mathcal E_a\longrightarrow\mathcal E_x,
    \quad v\longmapsto T_a(x)v,
    
e^{-H}Introduction passage · 1 passage

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  • Introduction passage · monograph_atlas.tex, line 704

    vpage36A positive transfer determines its HamiltonianSTRICT POSITIVITY AND THE GROUND GAPTraditional edition: Theorem II.10.2, Proposition II.10.5. On HH= C^3, take the strictly positive contraction T=diag(1,1/2,1/4), H=-log T=diag(0,log2,2log2). At unit Euclidean time, T=e^-H. The self-adjoint logarithm is unique because the logarithm acts on positive spectral values. At integer time n≥0, T^n=diag(1,2^-n,4^-n), P_0=diag(1,0,0), normT^n-P_0=2^-n. The gap Δ=log2 determines the rate e^-nΔ exactly …

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    T=e^{-H}
e^{-H'}Introduction passage · 1 passage

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  • Introduction passage · monograph_atlas.tex, line 712

    integer time n≥0, T^n=diag(1,2^-n,4^-n), P_0=diag(1,0,0), normT^n-P_0=2^-n. The gap Δ=log2 determines the rate e^-nΔ exactly in this example. xfigtransfer_ground headStrict positivity is an essential finite hypothesis For T'=diag(1,0), the operator is positive semidefinite, but there is no finite self-adjoint H' on all of C^2 with T'=e^-H': every finite eigenvalue of H' exponentiates to a strictly positive value. One may restrict to the positive support, but that changes the space on which the l…

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    T'=e^{-H'}
e^{-i(t-s)H}Introduction passage · 1 passage

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  • Introduction passage · Read passage · 04_alternative_derivations.tex, line 12

    ive conclusions are included there. Duhamel proof of leakage from a fixed packet. Let H=H^* on a finite-dimensional complex Hilbert space, P=P^*=P^2, Q=I-P, and t∈ R. [Alternative proof of the commutator leakage bound] Because QP=0, Qe^-itHP=Q[e^-itH,P]P. The Duhamel identity gives [e^-itH,P]=-i∫_0^t e^-i(t-s)H[H,P]e^-isH ds. Both unitary factors have norm one, so taking norms and using the integration interval's length |t| yields Qe^-itHP ≤ |t| [H,P] . Proof of projected curvature with exterior…

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    [e^{-itH},P]=-i\int_0^t e^{-i(t-s)H}[H,P]e^{-isH}\,ds.
    
e^{-isH}Introduction passage · 3 passages

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  • Introduction passage · Read passage · 04_alternative_derivations.tex, line 12

    ive conclusions are included there. Duhamel proof of leakage from a fixed packet. Let H=H^* on a finite-dimensional complex Hilbert space, P=P^*=P^2, Q=I-P, and t∈ R. [Alternative proof of the commutator leakage bound] Because QP=0, Qe^-itHP=Q[e^-itH,P]P. The Duhamel identity gives [e^-itH,P]=-i∫_0^t e^-i(t-s)H[H,P]e^-isH ds. Both unitary factors have norm one, so taking norms and using the integration interval's length |t| yields Qe^-itHP ≤ |t| [H,P] . Proof of projected curvature with exterior…

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    [e^{-itH},P]=-i\int_0^t e^{-i(t-s)H}[H,P]e^{-isH}\,ds.
    
e^{-itH}Introduction passage · 7 passages

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  • Introduction passage · Read passage · 04_alternative_derivations.tex, line 12

    ive conclusions are included there. Duhamel proof of leakage from a fixed packet. Let H=H^* on a finite-dimensional complex Hilbert space, P=P^*=P^2, Q=I-P, and t∈ R. [Alternative proof of the commutator leakage bound] Because QP=0, Qe^-itHP=Q[e^-itH,P]P. The Duhamel identity gives [e^-itH,P]=-i∫_0^t e^-i(t-s)H[H,P]e^-isH ds. Both unitary factors have norm one, so taking norms and using the integration interval's length |t| yields Qe^-itHP ≤ |t| [H,P] . Proof of projected curvature with exterior…

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    [e^{-itH},P]=-i\int_0^t e^{-i(t-s)H}[H,P]e^{-isH}\,ds.
    
e^{-n\Delta}Introduction passage · 1 passage

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  • Introduction passage · monograph_atlas.tex, line 709

    HH= C^3, take the strictly positive contraction T=diag(1,1/2,1/4), H=-log T=diag(0,log2,2log2). At unit Euclidean time, T=e^-H. The self-adjoint logarithm is unique because the logarithm acts on positive spectral values. At integer time n≥0, T^n=diag(1,2^-n,4^-n), P_0=diag(1,0,0), normT^n-P_0=2^-n. The gap Δ=log2 determines the rate e^-nΔ exactly in this example. xfigtransfer_ground headStrict positivity is an essential finite hypothesis For T'=diag(1,0), the operator is positive semidefinite, b…

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E_aIntroduction passage · 36 passages

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  • Introduction passage · Read passage · 02_strengthened.tex, line 1485

    [Correctable observable algebras] Let Φ be a finite completely positive trace preserving channel with Kraus operators (E_a). A finite dimensional unital star subalgebra M⊆ PEnd( H)P is correctable when a completely positive trace preserving recovery R satisfies P(Φ^*∘ R^*)(X)P=X for every X∈ M, where stars on maps denote Heisenberg adjoints. This holds exactly when every compressed product PE_a^*E_bP belongs to the commutant M' on the code. The scalar code criterion is the special case M=PEnd( H…

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\mathcal E_aIntroduction passage · 5 passages

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  • Introduction passage · Read passage · 03_supplement_06.tex, line 34

    The mutually inverse local maps. Write T_a(x)=T(P(x),P(a)). For x∈ U_a, B_a(x): E_a⟶ E_x, v⟼ T_a(x)v, A_a(x): E_x⟶ E_a, w⟼ P(a)T_a(x)^-1w. The intertwining identity and its inverse counterpart show that the displayed targets are correct. Lean proves both inverse laws, continuity, linearity in the fiber and smooth dependence on the base. Thus E|_U_a ≅ U_a× E_a is a local product homeomorphism that preserves the base point.

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    B_a(x):\mathcal E_a\longrightarrow\mathcal E_x,
    \quad v\longmapsto T_a(x)v,
    
\mathcal E_xIntroduction passage · 5 passages

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  • Introduction passage · Read passage · 03_supplement_06.tex, line 34

    The mutually inverse local maps. Write T_a(x)=T(P(x),P(a)). For x∈ U_a, B_a(x): E_a⟶ E_x, v⟼ T_a(x)v, A_a(x): E_x⟶ E_a, w⟼ P(a)T_a(x)^-1w. The intertwining identity and its inverse counterpart show that the displayed targets are correct. Lean proves both inverse laws, continuity, linearity in the fiber and smooth dependence on the base. Thus E|_U_a ≅ U_a× E_a is a local product homeomorphism that preserves the base point.

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    B_a(x):\mathcal E_a\longrightarrow\mathcal E_x,
    \quad v\longmapsto T_a(x)v,
    
\mathcal HIntroduction passage · 3 passages

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  • Introduction passage · Read passage · 03_supplement_03.tex, line 35

    Simultaneous generation in a direct sum. For the stipulated block representation A=⊕_i(M_d_i( C)⊗ I_m_i), d_i>0, the proof establishes that k seeds generate all blocks simultaneously exactly when m_i≤ kd_i for every i. It follows that srank_ A( H)=max_ilceilfracm_id_irceil. The final Lean proposition is an codeIsLeast statement over the set of feasible seed counts. It proves both attainment and minimality. For an empty block family the finite supremum is defined as 0, matching the zero module.

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    \boxed{\srank_{\mathcal A}(\mathcal H)=\max_i\left\lceil\frac{m_i}{d_i}\right\rceil.}
    
H'Introduction passage · 3 passages

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  • Introduction passage · monograph_atlas.tex, line 712

    positive spectral values. At integer time n≥0, T^n=diag(1,2^-n,4^-n), P_0=diag(1,0,0), normT^n-P_0=2^-n. The gap Δ=log2 determines the rate e^-nΔ exactly in this example. xfigtransfer_ground headStrict positivity is an essential finite hypothesis For T'=diag(1,0), the operator is positive semidefinite, but there is no finite self-adjoint H' on all of C^2 with T'=e^-H': every finite eigenvalue of H' exponentiates to a strictly positive value. One may restrict to the positive support, but that cha…

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iIntroduction passage · 92 passages

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  • Introduction passage · Read passage · 03_supplement_02.tex, line 91

    Fix a real time t and a finite complex coordinate space. Let U(s) be a unitary matrix curve, differentiable entrywise at t, and let ψ(s) be differentiable componentwise at t. Write dot U and dotψ for those derivatives. Suppose idotψ=Hψ(t). Only the value of the Hamiltonian at the chosen time is needed. No derivative of H is assumed.

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     i\dot\psi=H\psi(t).
    
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  • Introduction passage · Read passage · 03_supplement_05.tex, line 146

    An arbitrary finite reference system. For any finite reference index set A, the amplified channel is defined using the actual Kronecker Kraus operators, widetilde N_E(ρ) =∑_a(I_A⊗ E_a)ρ(I_A⊗ E_a)^*. Its reference blocks are proved equal to the original channel applied blockwise. If (I_A⊗ P)ρ(I_A⊗ P)=ρ, then every reference block is code supported. Applying the checked correction theorem for operators to those blocks gives widetilde R widetilde N_E(ρ)=ρ. This includes entangled density matrices s…

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    \widetilde{\mathcal N}_E(\rho)
    =\sum_a(I_A\otimes E_a)\rho(I_A\otimes E_a)^*.
    
I_{m_i}Introduction passage · 3 passages

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  • Introduction passage · Read passage · 03_supplement_03.tex, line 31

    Simultaneous generation in a direct sum. For the stipulated block representation A=⊕_i(M_d_i( C)⊗ I_m_i), d_i>0, the proof establishes that k seeds generate all blocks simultaneously exactly when m_i≤ kd_i for every i. It follows that srank_ A( H)=max_ilceilfracm_id_irceil. The final Lean proposition is an codeIsLeast statement over the set of feasible seed counts. It proves both attainment and minimality. For an empty block family the finite supremum is defined as 0, matching the zero module.

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    \mathcal A=\bigoplus_i\bigl(M_{d_i}(\C)\otimes I_{m_i}\bigr),\qquad d_i>0,
    
jIntroduction passage · 138 passages

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  • Introduction passage · Read passage · 01_finite_core.tex, line 160

    [One seed for the computational basis] For an integer n≥0, let ψ_0=ket0^⊗ n and let X_j denote the Pauli X operator on qubit j. Then { X_1^a_1⋯ X_n^a_nψ_0: (a_1,…,a_n)∈{0,1}^n } is the complete computational basis. Hence the seed is cyclic under the algebra generated by the X_j.

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\ketIntroduction passage · 99 passages

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  • Introduction passage · Read passage · 01_finite_core.tex, line 157

    [One seed for the computational basis] For an integer n≥0, let ψ_0=ket0^⊗ n and let X_j denote the Pauli X operator on qubit j. Then { X_1^a_1⋯ X_n^a_nψ_0: (a_1,…,a_n)∈{0,1}^n } is the complete computational basis. Hence the seed is cyclic under the algebra generated by the X_j.

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    \psi_0=\ket{0}^{\otimes n}
    
\lceilIntroduction passage · 9 passages

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  • Introduction passage · Read passage · 03_supplement_03.tex, line 35

    Simultaneous generation in a direct sum. For the stipulated block representation A=⊕_i(M_d_i( C)⊗ I_m_i), d_i>0, the proof establishes that k seeds generate all blocks simultaneously exactly when m_i≤ kd_i for every i. It follows that srank_ A( H)=max_ilceilfracm_id_irceil. The final Lean proposition is an codeIsLeast statement over the set of feasible seed counts. It proves both attainment and minimality. For an empty block family the finite supremum is defined as 0, matching the zero module.

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    \boxed{\srank_{\mathcal A}(\mathcal H)=\max_i\left\lceil\frac{m_i}{d_i}\right\rceil.}
    
MIntroduction passage · 33 passages

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  • Introduction passage · Read passage · 03_supplement_03.tex, line 31

    Simultaneous generation in a direct sum. For the stipulated block representation A=⊕_i(M_d_i( C)⊗ I_m_i), d_i>0, the proof establishes that k seeds generate all blocks simultaneously exactly when m_i≤ kd_i for every i. It follows that srank_ A( H)=max_ilceilfracm_id_irceil. The final Lean proposition is an codeIsLeast statement over the set of feasible seed counts. It proves both attainment and minimality. For an empty block family the finite supremum is defined as 0, matching the zero module.

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    \mathcal A=\bigoplus_i\bigl(M_{d_i}(\C)\otimes I_{m_i}\bigr),\qquad d_i>0,
    
mIntroduction passage · 98 passages

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  • Introduction passage · Read passage · 03_supplement_03.tex, line 31

    Simultaneous generation in a direct sum. For the stipulated block representation A=⊕_i(M_d_i( C)⊗ I_m_i), d_i>0, the proof establishes that k seeds generate all blocks simultaneously exactly when m_i≤ kd_i for every i. It follows that srank_ A( H)=max_ilceilfracm_id_irceil. The final Lean proposition is an codeIsLeast statement over the set of feasible seed counts. It proves both attainment and minimality. For an empty block family the finite supremum is defined as 0, matching the zero module.

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    \mathcal A=\bigoplus_i\bigl(M_{d_i}(\C)\otimes I_{m_i}\bigr),\qquad d_i>0,
    
M_{d_i}Introduction passage · 3 passages

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  • Introduction passage · Read passage · 03_supplement_03.tex, line 31

    Simultaneous generation in a direct sum. For the stipulated block representation A=⊕_i(M_d_i( C)⊗ I_m_i), d_i>0, the proof establishes that k seeds generate all blocks simultaneously exactly when m_i≤ kd_i for every i. It follows that srank_ A( H)=max_ilceilfracm_id_irceil. The final Lean proposition is an codeIsLeast statement over the set of feasible seed counts. It proves both attainment and minimality. For an empty block family the finite supremum is defined as 0, matching the zero module.

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    \mathcal A=\bigoplus_i\bigl(M_{d_i}(\C)\otimes I_{m_i}\bigr),\qquad d_i>0,
    
m_iIntroduction passage · 16 passages

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  • Introduction passage · Read passage · 03_supplement_03.tex, line 31

    Simultaneous generation in a direct sum. For the stipulated block representation A=⊕_i(M_d_i( C)⊗ I_m_i), d_i>0, the proof establishes that k seeds generate all blocks simultaneously exactly when m_i≤ kd_i for every i. It follows that srank_ A( H)=max_ilceilfracm_id_irceil. The final Lean proposition is an codeIsLeast statement over the set of feasible seed counts. It proves both attainment and minimality. For an empty block family the finite supremum is defined as 0, matching the zero module.

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    \mathcal A=\bigoplus_i\bigl(M_{d_i}(\C)\otimes I_{m_i}\bigr),\qquad d_i>0,
    
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  • Introduction passage · Read passage · 03_supplement_03.tex, line 35

    Simultaneous generation in a direct sum. For the stipulated block representation A=⊕_i(M_d_i( C)⊗ I_m_i), d_i>0, the proof establishes that k seeds generate all blocks simultaneously exactly when m_i≤ kd_i for every i. It follows that srank_ A( H)=max_ilceilfracm_id_irceil. The final Lean proposition is an codeIsLeast statement over the set of feasible seed counts. It proves both attainment and minimality. For an empty block family the finite supremum is defined as 0, matching the zero module.

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    \boxed{\srank_{\mathcal A}(\mathcal H)=\max_i\left\lceil\frac{m_i}{d_i}\right\rceil.}
    
\McalIntroduction passage · 4 passages

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  • Introduction passage · Read passage · 02_strengthened.tex, line 1485

    [Correctable observable algebras] Let Φ be a finite completely positive trace preserving channel with Kraus operators (E_a). A finite dimensional unital star subalgebra M⊆ PEnd( H)P is correctable when a completely positive trace preserving recovery R satisfies P(Φ^*∘ R^*)(X)P=X for every X∈ M, where stars on maps denote Heisenberg adjoints. This holds exactly when every compressed product PE_a^*E_bP belongs to the commutant M' on the code. The scalar code criterion is the special case M=PEnd( H…

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    \Mcal\subseteq P\End(\Hcal)P
\Mcal'Introduction passage · 1 passage

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  • Introduction passage · Read passage · 02_strengthened.tex, line 1485

    hannel with Kraus operators (E_a). A finite dimensional unital star subalgebra M⊆ PEnd( H)P is correctable when a completely positive trace preserving recovery R satisfies P(Φ^*∘ R^*)(X)P=X for every X∈ M, where stars on maps denote Heisenberg adjoints. This holds exactly when every compressed product PE_a^*E_bP belongs to the commutant M' on the code. The scalar code criterion is the special case M=PEnd( H)P [source reference].

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    \Mcal'
nIntroduction passage · 119 passages

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  • Introduction passage · monograph_atlas.tex, line 704

    ransfer determines its HamiltonianSTRICT POSITIVITY AND THE GROUND GAPTraditional edition: Theorem II.10.2, Proposition II.10.5. On HH= C^3, take the strictly positive contraction T=diag(1,1/2,1/4), H=-log T=diag(0,log2,2log2). At unit Euclidean time, T=e^-H. The self-adjoint logarithm is unique because the logarithm acts on positive spectral values. At integer time n≥0, T^n=diag(1,2^-n,4^-n), P_0=diag(1,0,0), normT^n-P_0=2^-n. The gap Δ=log2 determines the rate e^-nΔ exactly in this example. xf…

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    n\geq0
\overline{\psi_{i\ell}}Introduction passage · 1 passage

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  • Introduction passage · Read passage · 03_supplement_03.tex, line 70

    The actual partial trace and its support. The reduced matrix is defined by tracing the addressed index of the density matrix of the pure state: (ρ_B)_jℓ=∑_iψ_ijoverlineψ_iℓ. For the coefficient convention used here, the exact Gram identity is ρ_B=C^ T(C^ T)^*, rankρ_B=rank C=r(ψ). The transpose is important. With this convention, writing C^*C instead would conjugate the reduced matrix. The Lean source checks the entrywise identity and positivity of the resulting matrix.

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    (\rho_B)_{j\ell}=\sum_i\psi_{ij}\overline{\psi_{i\ell}}.
    
P^2Introduction passage · 10 passages

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  • Introduction passage · Read passage · 01_finite_core.tex, line 616

    textitCurvature. Differentiating P^2=P gives P(dP(X))P=0. Write D_Xs=ds(X). For ambient smooth sections, D_XD_Ys-D_YD_Xs-D_[X,Y]s=0. Expansion of the projected derivatives therefore leaves R(X,Y)s=P(dP(X))D_Ys-P(dP(Y))D_Xs. Since Ps=s, differentiation gives D_Ys=(dP(Y))s+PD_Ys. The terms with a middle P vanish. Thus R(X,Y)s=P(dP(X)dP(Y)-dP(Y)dP(X))P s. This expression is alternating and bilinear in the tangent vectors, and it preserves the range. The ordinary chain rule and the transformation la…

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    P^2=P
P_0Introduction passage · 9 passages

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  • Introduction passage · monograph_atlas.tex, line 705

    ermines its HamiltonianSTRICT POSITIVITY AND THE GROUND GAPTraditional edition: Theorem II.10.2, Proposition II.10.5. On HH= C^3, take the strictly positive contraction T=diag(1,1/2,1/4), H=-log T=diag(0,log2,2log2). At unit Euclidean time, T=e^-H. The self-adjoint logarithm is unique because the logarithm acts on positive spectral values. At integer time n≥0, T^n=diag(1,2^-n,4^-n), P_0=diag(1,0,0), normT^n-P_0=2^-n. The gap Δ=log2 determines the rate e^-nΔ exactly in this example. xfigtransfer_…

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    T^n=\diag(1,2^{-n},4^{-n}),\qquad
    P_0=\diag(1,0,0),\qquad\norm{T^n-P_0}=2^{-n}.
    
P_\alphaIntroduction passage · 16 passages

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  • Introduction passage · Read passage · 01_finite_core.tex, line 5

    Conventions. Unless the zero space is explicitly included as a boundary case, quantum state spaces are nonzero complex Hilbert spaces of finite dimension. A complete packet family is a finite collection satisfying P_α^*=P_α, P_α P_β=δ_αβP_α, ∑_α P_α=I. All operator norms in the analytic estimates are induced by the norm on the Hilbert space. The estimates do not use the entrywise maximum norm or the Frobenius norm. We write [A,B]=AB-BA and use units with ℏ=1. Parameter derivatives are real deriv…

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    P_\alpha^*=P_\alpha,\qquad
    P_\alpha P_\beta=\delta_{\alpha\beta}P_\alpha,\qquad
    \sum_\alpha P_\alpha=I.
    
P_\alpha^*Introduction passage · 1 passage

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  • Introduction passage · Read passage · 01_finite_core.tex, line 5

    Conventions. Unless the zero space is explicitly included as a boundary case, quantum state spaces are nonzero complex Hilbert spaces of finite dimension. A complete packet family is a finite collection satisfying P_α^*=P_α, P_α P_β=δ_αβP_α, ∑_α P_α=I. All operator norms in the analytic estimates are induced by the norm on the Hilbert space. The estimates do not use the entrywise maximum norm or the Frobenius norm. We write [A,B]=AB-BA and use units with ℏ=1. Parameter derivatives are real deriv…

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    P_\alpha^*=P_\alpha,\qquad
    P_\alpha P_\beta=\delta_{\alpha\beta}P_\alpha,\qquad
    \sum_\alpha P_\alpha=I.
    
P_\betaIntroduction passage · 7 passages

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  • Introduction passage · Read passage · 01_finite_core.tex, line 5

    Conventions. Unless the zero space is explicitly included as a boundary case, quantum state spaces are nonzero complex Hilbert spaces of finite dimension. A complete packet family is a finite collection satisfying P_α^*=P_α, P_α P_β=δ_αβP_α, ∑_α P_α=I. All operator norms in the analytic estimates are induced by the norm on the Hilbert space. The estimates do not use the entrywise maximum norm or the Frobenius norm. We write [A,B]=AB-BA and use units with ℏ=1. Parameter derivatives are real deriv…

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    P_\alpha^*=P_\alpha,\qquad
    P_\alpha P_\beta=\delta_{\alpha\beta}P_\alpha,\qquad
    \sum_\alpha P_\alpha=I.
    
QIntroduction passage · 97 passages

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  • Introduction passage · Read passage · 03_supplement_05.tex, line 71

    A channel on the whole ambient space. Put Q=I-∑_r∈ A_+V_rV_r^*. The recovery is R(σ)=∑_r∈ A_+V_r^*σ V_r+Qσ Q. The complement is an orthogonal projector and ∑_r∈ A_+V_rV_r^*+Q^*Q=I. Hence the recovery is trace preserving. Its finite Kraus form also proves positivity after amplification by the identity on every finite auxiliary space. The complement term matters: the map is defined as a channel even outside the syndrome ranges.

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    Q=I-\sum_{r\in A_+}V_rV_r^*
Q^*Introduction passage · 2 passages

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  • Introduction passage · Read passage · 03_supplement_05.tex, line 76

    A channel on the whole ambient space. Put Q=I-∑_r∈ A_+V_rV_r^*. The recovery is R(σ)=∑_r∈ A_+V_r^*σ V_r+Qσ Q. The complement is an orthogonal projector and ∑_r∈ A_+V_rV_r^*+Q^*Q=I. Hence the recovery is trace preserving. Its finite Kraus form also proves positivity after amplification by the identity on every finite auxiliary space. The complement term matters: the map is defined as a channel even outside the syndrome ranges.

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    \sum_{r\in A_+}V_rV_r^*+Q^*Q=I.
    
\mathcal RIntroduction passage · 14 passages

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  • Introduction passage · Read passage · 03_supplement_05.tex, line 72

    A channel on the whole ambient space. Put Q=I-∑_r∈ A_+V_rV_r^*. The recovery is R(σ)=∑_r∈ A_+V_r^*σ V_r+Qσ Q. The complement is an orthogonal projector and ∑_r∈ A_+V_rV_r^*+Q^*Q=I. Hence the recovery is trace preserving. Its finite Kraus form also proves positivity after amplification by the identity on every finite auxiliary space. The complement term matters: the map is defined as a channel even outside the syndrome ranges.

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    \boxed{\mathcal R(\sigma)=\sum_{r\in A_+}V_r^*\sigma V_r+Q\sigma Q.}
    
\rankIntroduction passage · 17 passages

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  • Introduction passage · Read passage · 03_supplement_03.tex, line 74

    The actual partial trace and its support. The reduced matrix is defined by tracing the addressed index of the density matrix of the pure state: (ρ_B)_jℓ=∑_iψ_ijoverlineψ_iℓ. For the coefficient convention used here, the exact Gram identity is ρ_B=C^ T(C^ T)^*, rankρ_B=rank C=r(ψ). The transpose is important. With this convention, writing C^*C instead would conjugate the reduced matrix. The Lean source checks the entrywise identity and positivity of the resulting matrix.

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    \rho_B=C^{\mathsf T}(C^{\mathsf T})^*,
    \qquad \rank\rho_B=\rank C=r(\psi).
    
\RcalIntroduction passage · 11 passages

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  • Introduction passage · Read passage · 02_strengthened.tex, line 1485

    [Correctable observable algebras] Let Φ be a finite completely positive trace preserving channel with Kraus operators (E_a). A finite dimensional unital star subalgebra M⊆ PEnd( H)P is correctable when a completely positive trace preserving recovery R satisfies P(Φ^*∘ R^*)(X)P=X for every X∈ M, where stars on maps denote Heisenberg adjoints. This holds exactly when every compressed product PE_a^*E_bP belongs to the commutant M' on the code. The scalar code criterion is the special case M=PEnd( H…

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    \Rcal
\Rcal^*Introduction passage · 1 passage

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  • Introduction passage · Read passage · 02_strengthened.tex, line 1485

    [Correctable observable algebras] Let Φ be a finite completely positive trace preserving channel with Kraus operators (E_a). A finite dimensional unital star subalgebra M⊆ PEnd( H)P is correctable when a completely positive trace preserving recovery R satisfies P(Φ^*∘ R^*)(X)P=X for every X∈ M, where stars on maps denote Heisenberg adjoints. This holds exactly when every compressed product PE_a^*E_bP belongs to the commutant M' on the code. The scalar code criterion is the special case M=PEnd( H…

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    P(\Phi^*\circ\Rcal^*)(X)P=X
\rceilIntroduction passage · 9 passages

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  • Introduction passage · Read passage · 03_supplement_03.tex, line 35

    Simultaneous generation in a direct sum. For the stipulated block representation A=⊕_i(M_d_i( C)⊗ I_m_i), d_i>0, the proof establishes that k seeds generate all blocks simultaneously exactly when m_i≤ kd_i for every i. It follows that srank_ A( H)=max_ilceilfracm_id_irceil. The final Lean proposition is an codeIsLeast statement over the set of feasible seed counts. It proves both attainment and minimality. For an empty block family the finite supremum is defined as 0, matching the zero module.

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    \boxed{\srank_{\mathcal A}(\mathcal H)=\max_i\left\lceil\frac{m_i}{d_i}\right\rceil.}
    
sIntroduction passage · 96 passages

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  • Introduction passage · Read passage · 01_finite_core.tex, line 616

    textitCurvature. Differentiating P^2=P gives P(dP(X))P=0. Write D_Xs=ds(X). For ambient smooth sections, D_XD_Ys-D_YD_Xs-D_[X,Y]s=0. Expansion of the projected derivatives therefore leaves R(X,Y)s=P(dP(X))D_Ys-P(dP(Y))D_Xs. Since Ps=s, differentiation gives D_Ys=(dP(Y))s+PD_Ys. The terms with a middle P vanish. Thus R(X,Y)s=P(dP(X)dP(Y)-dP(Y)dP(X))P s. This expression is alternating and bilinear in the tangent vectors, and it preserves the range. The ordinary chain rule and the transformation la…

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    D_Xs=ds(X)
\srankIntroduction passage · 1 passage

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  • Introduction passage · Read passage · 03_supplement_03.tex, line 35

    Simultaneous generation in a direct sum. For the stipulated block representation A=⊕_i(M_d_i( C)⊗ I_m_i), d_i>0, the proof establishes that k seeds generate all blocks simultaneously exactly when m_i≤ kd_i for every i. It follows that srank_ A( H)=max_ilceilfracm_id_irceil. The final Lean proposition is an codeIsLeast statement over the set of feasible seed counts. It proves both attainment and minimality. For an empty block family the finite supremum is defined as 0, matching the zero module.

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    \boxed{\srank_{\mathcal A}(\mathcal H)=\max_i\left\lceil\frac{m_i}{d_i}\right\rceil.}
    
\srank_{\mathcal A}Introduction passage · 1 passage

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  • Introduction passage · Read passage · 03_supplement_03.tex, line 35

    Simultaneous generation in a direct sum. For the stipulated block representation A=⊕_i(M_d_i( C)⊗ I_m_i), d_i>0, the proof establishes that k seeds generate all blocks simultaneously exactly when m_i≤ kd_i for every i. It follows that srank_ A( H)=max_ilceilfracm_id_irceil. The final Lean proposition is an codeIsLeast statement over the set of feasible seed counts. It proves both attainment and minimality. For an empty block family the finite supremum is defined as 0, matching the zero module.

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    \boxed{\srank_{\mathcal A}(\mathcal H)=\max_i\left\lceil\frac{m_i}{d_i}\right\rceil.}
    
\mathsf TIntroduction passage · 14 passages

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  • Introduction passage · Read passage · 03_supplement_03.tex, line 74

    The actual partial trace and its support. The reduced matrix is defined by tracing the addressed index of the density matrix of the pure state: (ρ_B)_jℓ=∑_iψ_ijoverlineψ_iℓ. For the coefficient convention used here, the exact Gram identity is ρ_B=C^ T(C^ T)^*, rankρ_B=rank C=r(ψ). The transpose is important. With this convention, writing C^*C instead would conjugate the reduced matrix. The Lean source checks the entrywise identity and positivity of the resulting matrix.

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    \rho_B=C^{\mathsf T}(C^{\mathsf T})^*,
    \qquad \rank\rho_B=\rank C=r(\psi).
    
T'Introduction passage · 2 passages

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  • Introduction passage · monograph_atlas.tex, line 712

    lidean time, T=e^-H. The self-adjoint logarithm is unique because the logarithm acts on positive spectral values. At integer time n≥0, T^n=diag(1,2^-n,4^-n), P_0=diag(1,0,0), normT^n-P_0=2^-n. The gap Δ=log2 determines the rate e^-nΔ exactly in this example. xfigtransfer_ground headStrict positivity is an essential finite hypothesis For T'=diag(1,0), the operator is positive semidefinite, but there is no finite self-adjoint H' on all of C^2 with T'=e^-H': every finite eigenvalue of H' exponentia…

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    T'=\diag(1,0)
T^nIntroduction passage · 6 passages

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  • Introduction passage · monograph_atlas.tex, line 705

    ermines its HamiltonianSTRICT POSITIVITY AND THE GROUND GAPTraditional edition: Theorem II.10.2, Proposition II.10.5. On HH= C^3, take the strictly positive contraction T=diag(1,1/2,1/4), H=-log T=diag(0,log2,2log2). At unit Euclidean time, T=e^-H. The self-adjoint logarithm is unique because the logarithm acts on positive spectral values. At integer time n≥0, T^n=diag(1,2^-n,4^-n), P_0=diag(1,0,0), normT^n-P_0=2^-n. The gap Δ=log2 determines the rate e^-nΔ exactly in this example. xfigtransfer_…

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    T^n=\diag(1,2^{-n},4^{-n}),\qquad
    P_0=\diag(1,0,0),\qquad\norm{T^n-P_0}=2^{-n}.
    
T_aIntroduction passage · 15 passages

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  • Introduction passage · Read passage · 03_supplement_06.tex, line 33

    The mutually inverse local maps. Write T_a(x)=T(P(x),P(a)). For x∈ U_a, B_a(x): E_a⟶ E_x, v⟼ T_a(x)v, A_a(x): E_x⟶ E_a, w⟼ P(a)T_a(x)^-1w. The intertwining identity and its inverse counterpart show that the displayed targets are correct. Lean proves both inverse laws, continuity, linearity in the fiber and smooth dependence on the base. Thus E|_U_a ≅ U_a× E_a is a local product homeomorphism that preserves the base point.

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    T_a(x)=T(P(x),P(a))
T_xIntroduction passage · 1 passage

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  • Introduction passage · Read passage · 03_supplement_06.tex, line 65

    A connection on the constructed bundle. The global formula is defined using the actual manifold derivative: ∇_Xs(x)=P(x) D_Ms(x)[X(x)]. Here D_M is represented by pathmvfderiv. A second definition, pathGlobalConnection.covariant, has values in the actual fiber: ∇ s(x):T_xM⟶ E_x. It is not only an ambient expression asserted to land in the range.

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    \nabla s(x):T_xM\longrightarrow\mathcal E_x.
    
UIntroduction passage · 104 passages

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  • Introduction passage · Read passage · 02_strengthened.tex, line 200

    Let G be a finite group and let U:G⟶ U( H) be a unitary representation. Write widehat G for the set of irreducible unitary representations. For λ∈widehat G, let d_λ and χ_λ denote its dimension and character.

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    U:G\longrightarrow\Ucal(\Hcal)
    
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  • Introduction passage · Read passage · 03_supplement_06.tex, line 33

    The mutually inverse local maps. Write T_a(x)=T(P(x),P(a)). For x∈ U_a, B_a(x): E_a⟶ E_x, v⟼ T_a(x)v, A_a(x): E_x⟶ E_a, w⟼ P(a)T_a(x)^-1w. The intertwining identity and its inverse counterpart show that the displayed targets are correct. Lean proves both inverse laws, continuity, linearity in the fiber and smooth dependence on the base. Thus E|_U_a ≅ U_a× E_a is a local product homeomorphism that preserves the base point.

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    x\in U_a
\UcalIntroduction passage · 7 passages

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  • Introduction passage · Read passage · 02_strengthened.tex, line 200

    Let G be a finite group and let U:G⟶ U( H) be a unitary representation. Write widehat G for the set of irreducible unitary representations. For λ∈widehat G, let d_λ and χ_λ denote its dimension and character.

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    U:G\longrightarrow\Ucal(\Hcal)
    
VIntroduction passage · 60 passages

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  • Introduction passage · Read passage · 03_supplement_05.tex, line 71

    A channel on the whole ambient space. Put Q=I-∑_r∈ A_+V_rV_r^*. The recovery is R(σ)=∑_r∈ A_+V_r^*σ V_r+Qσ Q. The complement is an orthogonal projector and ∑_r∈ A_+V_rV_r^*+Q^*Q=I. Hence the recovery is trace preserving. Its finite Kraus form also proves positivity after amplification by the identity on every finite auxiliary space. The complement term matters: the map is defined as a channel even outside the syndrome ranges.

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    Q=I-\sum_{r\in A_+}V_rV_r^*
vIntroduction passage · 51 passages

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  • Introduction passage · Read passage · 03_supplement_06.tex, line 34

    The mutually inverse local maps. Write T_a(x)=T(P(x),P(a)). For x∈ U_a, B_a(x): E_a⟶ E_x, v⟼ T_a(x)v, A_a(x): E_x⟶ E_a, w⟼ P(a)T_a(x)^-1w. The intertwining identity and its inverse counterpart show that the displayed targets are correct. Lean proves both inverse laws, continuity, linearity in the fiber and smooth dependence on the base. Thus E|_U_a ≅ U_a× E_a is a local product homeomorphism that preserves the base point.

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    B_a(x):\mathcal E_a\longrightarrow\mathcal E_x,
    \quad v\longmapsto T_a(x)v,
    
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  • Introduction passage · Read passage · 03_supplement_05.tex, line 71

    A channel on the whole ambient space. Put Q=I-∑_r∈ A_+V_rV_r^*. The recovery is R(σ)=∑_r∈ A_+V_r^*σ V_r+Qσ Q. The complement is an orthogonal projector and ∑_r∈ A_+V_rV_r^*+Q^*Q=I. Hence the recovery is trace preserving. Its finite Kraus form also proves positivity after amplification by the identity on every finite auxiliary space. The complement term matters: the map is defined as a channel even outside the syndrome ranges.

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    Q=I-\sum_{r\in A_+}V_rV_r^*
V_r^*Introduction passage · 7 passages

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  • Introduction passage · Read passage · 03_supplement_05.tex, line 71

    A channel on the whole ambient space. Put Q=I-∑_r∈ A_+V_rV_r^*. The recovery is R(σ)=∑_r∈ A_+V_r^*σ V_r+Qσ Q. The complement is an orthogonal projector and ∑_r∈ A_+V_rV_r^*+Q^*Q=I. Hence the recovery is trace preserving. Its finite Kraus form also proves positivity after amplification by the identity on every finite auxiliary space. The complement term matters: the map is defined as a channel even outside the syndrome ranges.

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    Q=I-\sum_{r\in A_+}V_rV_r^*
wIntroduction passage · 18 passages

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  • Introduction passage · Read passage · 03_supplement_06.tex, line 38

    The mutually inverse local maps. Write T_a(x)=T(P(x),P(a)). For x∈ U_a, B_a(x): E_a⟶ E_x, v⟼ T_a(x)v, A_a(x): E_x⟶ E_a, w⟼ P(a)T_a(x)^-1w. The intertwining identity and its inverse counterpart show that the displayed targets are correct. Lean proves both inverse laws, continuity, linearity in the fiber and smooth dependence on the base. Thus E|_U_a ≅ U_a× E_a is a local product homeomorphism that preserves the base point.

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    A_a(x):\mathcal E_x\longrightarrow\mathcal E_a,
    \quad w\longmapsto P(a)T_a(x)^{-1}w.
    
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  • Introduction passage · Read passage · 04_alternative_derivations.tex, line 22

    eld and extend the projected connection to differential forms with values in the range bundle by ∇ω=P dω. Thus ∇^2 denotes the exterior covariant square, including the Lie bracket term in the exterior derivative when evaluated on vector fields. [Alternative proof of the curvature formula] For a section s with Ps=s, ∇^2s=P d(P ds)=P(dP)wedge ds. Since ds=d(Ps)=(dP)s+Pds and P(dP)P=0, the surviving term is P(dPwedge dP)Ps. Restricted low-mode proof. Let h≠0, x=kh/2, and 0≤ x≤1. [Alternative proof …

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    \nabla^2s=P\,d(P\,ds)=P(dP)\wedge ds.
    
\widehat GIntroduction passage · 4 passages

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  • Introduction passage · Read passage · 02_strengthened.tex, line 203

    Let G be a finite group and let U:G⟶ U( H) be a unitary representation. Write widehat G for the set of irreducible unitary representations. For λ∈widehat G, let d_λ and χ_λ denote its dimension and character.

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\widetilde{\mathcal N}Introduction passage · 2 passages

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  • Introduction passage · Read passage · 03_supplement_05.tex, line 146

    An arbitrary finite reference system. For any finite reference index set A, the amplified channel is defined using the actual Kronecker Kraus operators, widetilde N_E(ρ) =∑_a(I_A⊗ E_a)ρ(I_A⊗ E_a)^*. Its reference blocks are proved equal to the original channel applied blockwise. If (I_A⊗ P)ρ(I_A⊗ P)=ρ, then every reference block is code supported. Applying the checked correction theorem for operators to those blocks gives widetilde R widetilde N_E(ρ)=ρ. This includes entangled density matrices s…

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    \widetilde{\mathcal N}_E(\rho)
    =\sum_a(I_A\otimes E_a)\rho(I_A\otimes E_a)^*.
    
\widetilde{\mathcal N}_EIntroduction passage · 2 passages

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  • Introduction passage · Read passage · 03_supplement_05.tex, line 146

    An arbitrary finite reference system. For any finite reference index set A, the amplified channel is defined using the actual Kronecker Kraus operators, widetilde N_E(ρ) =∑_a(I_A⊗ E_a)ρ(I_A⊗ E_a)^*. Its reference blocks are proved equal to the original channel applied blockwise. If (I_A⊗ P)ρ(I_A⊗ P)=ρ, then every reference block is code supported. Applying the checked correction theorem for operators to those blocks gives widetilde R widetilde N_E(ρ)=ρ. This includes entangled density matrices s…

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    \widetilde{\mathcal N}_E(\rho)
    =\sum_a(I_A\otimes E_a)\rho(I_A\otimes E_a)^*.
    
\widetilde{\mathcal R}Introduction passage · 1 passage

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  • Introduction passage · Read passage · 03_supplement_05.tex, line 155

    channel is defined using the actual Kronecker Kraus operators, widetilde N_E(ρ) =∑_a(I_A⊗ E_a)ρ(I_A⊗ E_a)^*. Its reference blocks are proved equal to the original channel applied blockwise. If (I_A⊗ P)ρ(I_A⊗ P)=ρ, then every reference block is code supported. Applying the checked correction theorem for operators to those blocks gives widetilde R widetilde N_E(ρ)=ρ. This includes entangled density matrices supported on the combined reference and code space. In fact, the identity holds for every j…

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    \boxed{\widetilde{\mathcal R}\,\widetilde{\mathcal N}_E(\rho)=\rho.}
    
X_1^{a_1}Introduction passage · 4 passages

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  • Introduction passage · Read passage · 01_finite_core.tex, line 161

    [One seed for the computational basis] For an integer n≥0, let ψ_0=ket0^⊗ n and let X_j denote the Pauli X operator on qubit j. Then { X_1^a_1⋯ X_n^a_nψ_0: (a_1,…,a_n)∈{0,1}^n } is the complete computational basis. Hence the seed is cyclic under the algebra generated by the X_j.

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    \left\{
    X_1^{a_1}\cdots X_n^{a_n}\psi_0:
    (a_1,\ldots,a_n)\in\{0,1\}^n
    \right\}
    
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  • Introduction passage · Read passage · 01_finite_core.tex, line 160

    [One seed for the computational basis] For an integer n≥0, let ψ_0=ket0^⊗ n and let X_j denote the Pauli X operator on qubit j. Then { X_1^a_1⋯ X_n^a_nψ_0: (a_1,…,a_n)∈{0,1}^n } is the complete computational basis. Hence the seed is cyclic under the algebra generated by the X_j.

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X_n^{a_n}Introduction passage · 3 passages

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  • Introduction passage · Read passage · 01_finite_core.tex, line 161

    [One seed for the computational basis] For an integer n≥0, let ψ_0=ket0^⊗ n and let X_j denote the Pauli X operator on qubit j. Then { X_1^a_1⋯ X_n^a_nψ_0: (a_1,…,a_n)∈{0,1}^n } is the complete computational basis. Hence the seed is cyclic under the algebra generated by the X_j.

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    \left\{
    X_1^{a_1}\cdots X_n^{a_n}\psi_0:
    (a_1,\ldots,a_n)\in\{0,1\}^n
    \right\}
    
YIntroduction passage · 23 passages

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  • Introduction passage · Read passage · 01_finite_core.tex, line 617

    textitCurvature. Differentiating P^2=P gives P(dP(X))P=0. Write D_Xs=ds(X). For ambient smooth sections, D_XD_Ys-D_YD_Xs-D_[X,Y]s=0. Expansion of the projected derivatives therefore leaves R(X,Y)s=P(dP(X))D_Ys-P(dP(Y))D_Xs. Since Ps=s, differentiation gives D_Ys=(dP(Y))s+PD_Ys. The terms with a middle P vanish. Thus R(X,Y)s=P(dP(X)dP(Y)-dP(Y)dP(X))P s. This expression is alternating and bilinear in the tangent vectors, and it preserves the range. The ordinary chain rule and the transformation la…

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    D_XD_Ys-D_YD_Xs-D_{[X,Y]}s=0.
    
|Introduction passage · 34 passages

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  • Introduction passage · Read passage · 04_alternative_derivations.tex, line 15

    lex Hilbert space, P=P^*=P^2, Q=I-P, and t∈ R. [Alternative proof of the commutator leakage bound] Because QP=0, Qe^-itHP=Q[e^-itH,P]P. The Duhamel identity gives [e^-itH,P]=-i∫_0^t e^-i(t-s)H[H,P]e^-isH ds. Both unitary factors have norm one, so taking norms and using the integration interval's length |t| yields Qe^-itHP ≤ |t| [H,P] . Proof of projected curvature with exterior forms. Let P be a smooth idempotent field and extend the projected connection to differential forms with values in the …

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\betaIntroduction passage · 10 passages

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  • Introduction passage · Read passage · 01_finite_core.tex, line 5

    Conventions. Unless the zero space is explicitly included as a boundary case, quantum state spaces are nonzero complex Hilbert spaces of finite dimension. A complete packet family is a finite collection satisfying P_α^*=P_α, P_α P_β=δ_αβP_α, ∑_α P_α=I. All operator norms in the analytic estimates are induced by the norm on the Hilbert space. The estimates do not use the entrywise maximum norm or the Frobenius norm. We write [A,B]=AB-BA and use units with ℏ=1. Parameter derivatives are real deriv…

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    P_\alpha^*=P_\alpha,\qquad
    P_\alpha P_\beta=\delta_{\alpha\beta}P_\alpha,\qquad
    \sum_\alpha P_\alpha=I.
    
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  • Introduction passage · monograph_atlas.tex, line 709

    I.10.2, Proposition II.10.5. On HH= C^3, take the strictly positive contraction T=diag(1,1/2,1/4), H=-log T=diag(0,log2,2log2). At unit Euclidean time, T=e^-H. The self-adjoint logarithm is unique because the logarithm acts on positive spectral values. At integer time n≥0, T^n=diag(1,2^-n,4^-n), P_0=diag(1,0,0), normT^n-P_0=2^-n. The gap Δ=log2 determines the rate e^-nΔ exactly in this example. xfigtransfer_ground headStrict positivity is an essential finite hypothesis For T'=diag(1,0), the oper…

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\deltaIntroduction passage · 43 passages

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  • Introduction passage · Read passage · 01_finite_core.tex, line 5

    Conventions. Unless the zero space is explicitly included as a boundary case, quantum state spaces are nonzero complex Hilbert spaces of finite dimension. A complete packet family is a finite collection satisfying P_α^*=P_α, P_α P_β=δ_αβP_α, ∑_α P_α=I. All operator norms in the analytic estimates are induced by the norm on the Hilbert space. The estimates do not use the entrywise maximum norm or the Frobenius norm. We write [A,B]=AB-BA and use units with ℏ=1. Parameter derivatives are real deriv…

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    P_\alpha^*=P_\alpha,\qquad
    P_\alpha P_\beta=\delta_{\alpha\beta}P_\alpha,\qquad
    \sum_\alpha P_\alpha=I.
    
\delta_{\alpha\beta}Introduction passage · 1 passage

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  • Introduction passage · Read passage · 01_finite_core.tex, line 5

    Conventions. Unless the zero space is explicitly included as a boundary case, quantum state spaces are nonzero complex Hilbert spaces of finite dimension. A complete packet family is a finite collection satisfying P_α^*=P_α, P_α P_β=δ_αβP_α, ∑_α P_α=I. All operator norms in the analytic estimates are induced by the norm on the Hilbert space. The estimates do not use the entrywise maximum norm or the Frobenius norm. We write [A,B]=AB-BA and use units with ℏ=1. Parameter derivatives are real deriv…

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    P_\alpha^*=P_\alpha,\qquad
    P_\alpha P_\beta=\delta_{\alpha\beta}P_\alpha,\qquad
    \sum_\alpha P_\alpha=I.
    
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  • Introduction passage · Read passage · 03_supplement_03.tex, line 70

    The actual partial trace and its support. The reduced matrix is defined by tracing the addressed index of the density matrix of the pure state: (ρ_B)_jℓ=∑_iψ_ijoverlineψ_iℓ. For the coefficient convention used here, the exact Gram identity is ρ_B=C^ T(C^ T)^*, rankρ_B=rank C=r(ψ). The transpose is important. With this convention, writing C^*C instead would conjugate the reduced matrix. The Lean source checks the entrywise identity and positivity of the resulting matrix.

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    (\rho_B)_{j\ell}=\sum_i\psi_{ij}\overline{\psi_{i\ell}}.
    
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  • Introduction passage · Read passage · 03_supplement_03.tex, line 70

    The actual partial trace and its support. The reduced matrix is defined by tracing the addressed index of the density matrix of the pure state: (ρ_B)_jℓ=∑_iψ_ijoverlineψ_iℓ. For the coefficient convention used here, the exact Gram identity is ρ_B=C^ T(C^ T)^*, rankρ_B=rank C=r(ψ). The transpose is important. With this convention, writing C^*C instead would conjugate the reduced matrix. The Lean source checks the entrywise identity and positivity of the resulting matrix.

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    (\rho_B)_{j\ell}=\sum_i\psi_{ij}\overline{\psi_{i\ell}}.
    
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  • Introduction passage · Read passage · 03_supplement_05.tex, line 72

    A channel on the whole ambient space. Put Q=I-∑_r∈ A_+V_rV_r^*. The recovery is R(σ)=∑_r∈ A_+V_r^*σ V_r+Qσ Q. The complement is an orthogonal projector and ∑_r∈ A_+V_rV_r^*+Q^*Q=I. Hence the recovery is trace preserving. Its finite Kraus form also proves positivity after amplification by the identity on every finite auxiliary space. The complement term matters: the map is defined as a channel even outside the syndrome ranges.

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    \boxed{\mathcal R(\sigma)=\sum_{r\in A_+}V_r^*\sigma V_r+Q\sigma Q.}
    
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  • Introduction passage · Read passage · 02_strengthened.tex, line 1485

    [Correctable observable algebras] Let Φ be a finite completely positive trace preserving channel with Kraus operators (E_a). A finite dimensional unital star subalgebra M⊆ PEnd( H)P is correctable when a completely positive trace preserving recovery R satisfies P(Φ^*∘ R^*)(X)P=X for every X∈ M, where stars on maps denote Heisenberg adjoints. This holds exactly when every compressed product PE_a^*E_bP belongs to the commutant M' on the code. The scalar code criterion is the special case M=PEnd( H…

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  • Introduction passage · Read passage · 02_strengthened.tex, line 1485

    [Correctable observable algebras] Let Φ be a finite completely positive trace preserving channel with Kraus operators (E_a). A finite dimensional unital star subalgebra M⊆ PEnd( H)P is correctable when a completely positive trace preserving recovery R satisfies P(Φ^*∘ R^*)(X)P=X for every X∈ M, where stars on maps denote Heisenberg adjoints. This holds exactly when every compressed product PE_a^*E_bP belongs to the commutant M' on the code. The scalar code criterion is the special case M=PEnd( H…

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    P(\Phi^*\circ\Rcal^*)(X)P=X
\chiIntroduction passage · 7 passages

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  • Introduction passage · Read passage · 02_strengthened.tex, line 203

    Let G be a finite group and let U:G⟶ U( H) be a unitary representation. Write widehat G for the set of irreducible unitary representations. For λ∈widehat G, let d_λ and χ_λ denote its dimension and character.

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    \chi_\lambda
\chi_\lambdaIntroduction passage · 2 passages

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  • Introduction passage · Read passage · 02_strengthened.tex, line 203

    Let G be a finite group and let U:G⟶ U( H) be a unitary representation. Write widehat G for the set of irreducible unitary representations. For λ∈widehat G, let d_λ and χ_λ denote its dimension and character.

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\psi_{ij}Introduction passage · 3 passages

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  • Introduction passage · Read passage · 03_supplement_03.tex, line 70

    The actual partial trace and its support. The reduced matrix is defined by tracing the addressed index of the density matrix of the pure state: (ρ_B)_jℓ=∑_iψ_ijoverlineψ_iℓ. For the coefficient convention used here, the exact Gram identity is ρ_B=C^ T(C^ T)^*, rankρ_B=rank C=r(ψ). The transpose is important. With this convention, writing C^*C instead would conjugate the reduced matrix. The Lean source checks the entrywise identity and positivity of the resulting matrix.

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    (\rho_B)_{j\ell}=\sum_i\psi_{ij}\overline{\psi_{i\ell}}.
    
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  • Introduction passage · Read passage · 01_finite_core.tex, line 10

    of finite dimension. A complete packet family is a finite collection satisfying P_α^*=P_α, P_α P_β=δ_αβP_α, ∑_α P_α=I. All operator norms in the analytic estimates are induced by the norm on the Hilbert space. The estimates do not use the entrywise maximum norm or the Frobenius norm. We write [A,B]=AB-BA and use units with ℏ=1. Parameter derivatives are real derivatives. A matrix X is supported on a code projector P when PXP=X.

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    \hbar=1
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  • Introduction passage · Read passage · 03_supplement_06.tex, line 61

    A connection on the constructed bundle. The global formula is defined using the actual manifold derivative: ∇_Xs(x)=P(x) D_Ms(x)[X(x)]. Here D_M is represented by pathmvfderiv. A second definition, pathGlobalConnection.covariant, has values in the actual fiber: ∇ s(x):T_xM⟶ E_x. It is not only an ambient expression asserted to land in the range.

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    \nabla_Xs(x)=P(x)\,D_Ms(x)[X(x)].
    
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  • Introduction passage · Read passage · 04_alternative_derivations.tex, line 19

    rms and using the integration interval's length |t| yields Qe^-itHP ≤ |t| [H,P] . Proof of projected curvature with exterior forms. Let P be a smooth idempotent field and extend the projected connection to differential forms with values in the range bundle by ∇ω=P dω. Thus ∇^2 denotes the exterior covariant square, including the Lie bracket term in the exterior derivative when evaluated on vector fields. [Alternative proof of the curvature formula] For a section s with Ps=s, ∇^2s=P d(P ds)=P(dP)…

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  • Introduction passage · Read passage · 03_supplement_06.tex, line 61

    A connection on the constructed bundle. The global formula is defined using the actual manifold derivative: ∇_Xs(x)=P(x) D_Ms(x)[X(x)]. Here D_M is represented by pathmvfderiv. A second definition, pathGlobalConnection.covariant, has values in the actual fiber: ∇ s(x):T_xM⟶ E_x. It is not only an ambient expression asserted to land in the range.

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    \nabla_Xs(x)=P(x)\,D_Ms(x)[X(x)].
    
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  • Introduction passage · Read passage · 03_supplement_03.tex, line 70

    The actual partial trace and its support. The reduced matrix is defined by tracing the addressed index of the density matrix of the pure state: (ρ_B)_jℓ=∑_iψ_ijoverlineψ_iℓ. For the coefficient convention used here, the exact Gram identity is ρ_B=C^ T(C^ T)^*, rankρ_B=rank C=r(ψ). The transpose is important. With this convention, writing C^*C instead would conjugate the reduced matrix. The Lean source checks the entrywise identity and positivity of the resulting matrix.

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    (\rho_B)_{j\ell}=\sum_i\psi_{ij}\overline{\psi_{i\ell}}.
    
\sum_{r\in A_+}Introduction passage · 3 passages

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  • Introduction passage · Read passage · 03_supplement_05.tex, line 71

    A channel on the whole ambient space. Put Q=I-∑_r∈ A_+V_rV_r^*. The recovery is R(σ)=∑_r∈ A_+V_r^*σ V_r+Qσ Q. The complement is an orthogonal projector and ∑_r∈ A_+V_rV_r^*+Q^*Q=I. Hence the recovery is trace preserving. Its finite Kraus form also proves positivity after amplification by the identity on every finite auxiliary space. The complement term matters: the map is defined as a channel even outside the syndrome ranges.

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    Q=I-\sum_{r\in A_+}V_rV_r^*
\sum_\alphaIntroduction passage · 8 passages

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  • Introduction passage · Read passage · 01_finite_core.tex, line 5

    Conventions. Unless the zero space is explicitly included as a boundary case, quantum state spaces are nonzero complex Hilbert spaces of finite dimension. A complete packet family is a finite collection satisfying P_α^*=P_α, P_α P_β=δ_αβP_α, ∑_α P_α=I. All operator norms in the analytic estimates are induced by the norm on the Hilbert space. The estimates do not use the entrywise maximum norm or the Frobenius norm. We write [A,B]=AB-BA and use units with ℏ=1. Parameter derivatives are real deriv…

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    P_\alpha^*=P_\alpha,\qquad
    P_\alpha P_\beta=\delta_{\alpha\beta}P_\alpha,\qquad
    \sum_\alpha P_\alpha=I.
    
\circIntroduction passage · 3 passages

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  • Introduction passage · Read passage · 02_strengthened.tex, line 1485

    [Correctable observable algebras] Let Φ be a finite completely positive trace preserving channel with Kraus operators (E_a). A finite dimensional unital star subalgebra M⊆ PEnd( H)P is correctable when a completely positive trace preserving recovery R satisfies P(Φ^*∘ R^*)(X)P=X for every X∈ M, where stars on maps denote Heisenberg adjoints. This holds exactly when every compressed product PE_a^*E_bP belongs to the commutant M' on the code. The scalar code criterion is the special case M=PEnd( H…

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    P(\Phi^*\circ\Rcal^*)(X)P=X
\int_0^tIntroduction passage · 10 passages

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  • Introduction passage · Read passage · 04_alternative_derivations.tex, line 12

    ive conclusions are included there. Duhamel proof of leakage from a fixed packet. Let H=H^* on a finite-dimensional complex Hilbert space, P=P^*=P^2, Q=I-P, and t∈ R. [Alternative proof of the commutator leakage bound] Because QP=0, Qe^-itHP=Q[e^-itH,P]P. The Duhamel identity gives [e^-itH,P]=-i∫_0^t e^-i(t-s)H[H,P]e^-isH ds. Both unitary factors have norm one, so taking norms and using the integration interval's length |t| yields Qe^-itHP ≤ |t| [H,P] . Proof of projected curvature with exterior…

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    [e^{-itH},P]=-i\int_0^t e^{-i(t-s)H}[H,P]e^{-isH}\,ds.
    
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  • Introduction passage · Read passage · 03_supplement_03.tex, line 34

    Simultaneous generation in a direct sum. For the stipulated block representation A=⊕_i(M_d_i( C)⊗ I_m_i), d_i>0, the proof establishes that k seeds generate all blocks simultaneously exactly when m_i≤ kd_i for every i. It follows that srank_ A( H)=max_ilceilfracm_id_irceil. The final Lean proposition is an codeIsLeast statement over the set of feasible seed counts. It proves both attainment and minimality. For an empty block family the finite supremum is defined as 0, matching the zero module.

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    m_i\le kd_i
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  • Introduction passage · Read passage · 01_finite_core.tex, line 156

    [One seed for the computational basis] For an integer n≥0, let ψ_0=ket0^⊗ n and let X_j denote the Pauli X operator on qubit j. Then { X_1^a_1⋯ X_n^a_nψ_0: (a_1,…,a_n)∈{0,1}^n } is the complete computational basis. Hence the seed is cyclic under the algebra generated by the X_j.

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    n\ge0
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  • Introduction passage · monograph_atlas.tex, line 704

    ransfer determines its HamiltonianSTRICT POSITIVITY AND THE GROUND GAPTraditional edition: Theorem II.10.2, Proposition II.10.5. On HH= C^3, take the strictly positive contraction T=diag(1,1/2,1/4), H=-log T=diag(0,log2,2log2). At unit Euclidean time, T=e^-H. The self-adjoint logarithm is unique because the logarithm acts on positive spectral values. At integer time n≥0, T^n=diag(1,2^-n,4^-n), P_0=diag(1,0,0), normT^n-P_0=2^-n. The gap Δ=log2 determines the rate e^-nΔ exactly in this example. xf…

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  • Introduction passage · Read passage · 03_supplement_03.tex, line 31

    Simultaneous generation in a direct sum. For the stipulated block representation A=⊕_i(M_d_i( C)⊗ I_m_i), d_i>0, the proof establishes that k seeds generate all blocks simultaneously exactly when m_i≤ kd_i for every i. It follows that srank_ A( H)=max_ilceilfracm_id_irceil. The final Lean proposition is an codeIsLeast statement over the set of feasible seed counts. It proves both attainment and minimality. For an empty block family the finite supremum is defined as 0, matching the zero module.

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    \mathcal A=\bigoplus_i\bigl(M_{d_i}(\C)\otimes I_{m_i}\bigr),\qquad d_i>0,
    
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  • Introduction passage · Read passage · 03_supplement_03.tex, line 31

    Simultaneous generation in a direct sum. For the stipulated block representation A=⊕_i(M_d_i( C)⊗ I_m_i), d_i>0, the proof establishes that k seeds generate all blocks simultaneously exactly when m_i≤ kd_i for every i. It follows that srank_ A( H)=max_ilceilfracm_id_irceil. The final Lean proposition is an codeIsLeast statement over the set of feasible seed counts. It proves both attainment and minimality. For an empty block family the finite supremum is defined as 0, matching the zero module.

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    \mathcal A=\bigoplus_i\bigl(M_{d_i}(\C)\otimes I_{m_i}\bigr),\qquad d_i>0,
    
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  • Introduction passage · Read passage · 01_finite_core.tex, line 157

    [One seed for the computational basis] For an integer n≥0, let ψ_0=ket0^⊗ n and let X_j denote the Pauli X operator on qubit j. Then { X_1^a_1⋯ X_n^a_nψ_0: (a_1,…,a_n)∈{0,1}^n } is the complete computational basis. Hence the seed is cyclic under the algebra generated by the X_j.

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    \psi_0=\ket{0}^{\otimes n}
    
\cdotsIntroduction passage · 21 passages

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  • Introduction passage · Read passage · 01_finite_core.tex, line 161

    [One seed for the computational basis] For an integer n≥0, let ψ_0=ket0^⊗ n and let X_j denote the Pauli X operator on qubit j. Then { X_1^a_1⋯ X_n^a_nψ_0: (a_1,…,a_n)∈{0,1}^n } is the complete computational basis. Hence the seed is cyclic under the algebra generated by the X_j.

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    \left\{
    X_1^{a_1}\cdots X_n^{a_n}\psi_0:
    (a_1,\ldots,a_n)\in\{0,1\}^n
    \right\}
    
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  • Introduction passage · Read passage · 03_supplement_06.tex, line 34

    The mutually inverse local maps. Write T_a(x)=T(P(x),P(a)). For x∈ U_a, B_a(x): E_a⟶ E_x, v⟼ T_a(x)v, A_a(x): E_x⟶ E_a, w⟼ P(a)T_a(x)^-1w. The intertwining identity and its inverse counterpart show that the displayed targets are correct. Lean proves both inverse laws, continuity, linearity in the fiber and smooth dependence on the base. Thus E|_U_a ≅ U_a× E_a is a local product homeomorphism that preserves the base point.

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    B_a(x):\mathcal E_a\longrightarrow\mathcal E_x,
    \quad v\longmapsto T_a(x)v,
    
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  • Use in source · Read passage · 02_strengthened.tex, line 920

    The Pauli identity ( a·σ)( b·σ) =( a· b)I + i( a× b)·σ gives - iTr(P[∂_θ P,∂_ϕ P]) =frac12 n· (∂_θ n×∂_ϕ n) =frac12sinθ. Integrating the displayed curvature over the sphere and applying the stated normalization gives one.

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    (\bm a\cdot\bm\sigma)(\bm b\cdot\bm\sigma)
    =(\bm a\cdot\bm b)I
    +\ii(\bm a\times\bm b)\cdot\bm\sigma
    
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  • Use in source · Read passage · 01_finite_core.tex, line 651

    P,∂_ν P]). On the Bloch sphere, P(θ,ϕ) = frac12(I+ n(θ,ϕ)·σ), where n=(sinθcosϕ,sinθsinϕ,cosθ). The Pauli multiplication law gives [∂_θ P,∂_ϕ P] =fraci2(∂_θ nmathbin×∂_ϕ n)·σ. Using Tr(P a·σ)= n· a therefore yields F_θϕ =frac12 n·(∂_θ nmathbin×∂_ϕ n) =frac12sinθ. The scalar sign changes if the opposite convention for A is chosen. This explicit calculation is not a separate entry among the 19 items in the Lean register.

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    \Tr(P\,\mathbf a\cdot\boldsymbol\sigma)=\mathbf n\cdot\mathbf a
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  • Use in source · Read passage · 01_finite_core.tex, line 1199

    At one finite level, let widehat C_A be a finite family of matrix constraints, with fixed scalar structure coefficients, and let Π^phys be the orthogonal projector onto their exact common kernel. If the classical constraint algebra has structure coefficients f_AB^ C, define the anomaly operator A_AB = [widehat C_A,widehat C_B] -i∑_C f_AB^ Cwidehat C_C. Its physical packet is Π^phys A_ABΠ^phys. In this exact finite setting, widehat C_CΠ^phys=0 for every C. Associativity gives A_ABΠ^phys=0, Π^phys…

    Exact mathematical passage
    
    \boxed{
    \mathfrak A_{AB}
    =
    [\widehat C_A,\widehat C_B]
    -i\sum_C f_{AB}^{\ \ C}\widehat C_C.
    }
    
\mathfrak A^{(\ell)}_{AB}Use in source · 1 passage

Search aliases: A^(ℓ)_AB mathfrak ell

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  • Use in source · Read passage · 01_finite_core.tex, line 1223

    [Anomaly-free refinement] For a specified nontrivial quantum-geometric constraint model, there exists a coherent packet tower with nonzero physical spaces, compatible physical projectors and exact operator closure A^(ℓ)_AB=0 at every finite level. The compatible physical compression then vanishes as a consequence, not as a substitute for closure. The substantive research target is the operator condition. The earlier condition stated only in terms of compression was too weak. A choice of model, d…

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    \mathfrak A^{(\ell)}_{AB}=0
    
a^{-1}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 1860

    [Hamiltonian reconstruction from transfer] Let T be positive definite, self adjoint, and contractive. Then H_T=-a^-1log T is a nonnegative self adjoint operator and T^n= e^-naH_T. It is the unique nonnegative self adjoint operator with T= e^-aH_T.

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    H_T=-a^{-1}\log T
    
A^2Use in source · 3 passages

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  • Use in source · monograph_atlas.tex, line 694

    ct worked check specializes to t=(0,π/2,π) and v=(1,2,-1). Its phases lie in QQ( i), so both sides are computed without evaluating trigonometric functions. This Gram test illustrates the factorization. The written identity proves positivity for all choices of times and vectors. headWhy this does not close to a bare local equation With hidden initial state zero, the full system has ddot x(0)=-(A^2+BB^*)x(0)=-x(0). The bare retained equation idot x=Ax would instead give zero acceleration. Therefor…

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    \ddot x(0)=-(A^2+BB^*)x(0)=-x(0)
a_0Use in source · 10 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 389

    [Exact circuit path expansion] For source packet a_0 and target packet a_m, P_a_mUP_a_0 = ∑_a_1,…,a_m-1 P_a_mU_mP_a_m-1 ⋯ P_a_1U_1P_a_0. Summing over a_0 and a_m reconstructs U.

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    a_0
A_1Use in source · 3 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 366

    [Tensor selection rule] If A_a has local charge q_a, then A_1⊗⋯⊗ A_m has total charge q_1+⋯+q_m.

    Exact mathematical passage
    
    A_1\otimes\cdots\otimes A_m
    
a_2Use in source · 2 passages

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  • Use in source · monograph_atlas.tex, line 44

    vpage3One seed, eight addressesCYCLICITY DEPENDS ON THE GRAMMARTraditional edition: Proposition II.2.5. Start with ψ_0=ket000 and allow the three bit flip operators X_1,X_2,X_3. For a binary address a=(a_1,a_2,a_3), put W_a=X_1^a_1X_2^a_2X_3^a_3. W_aψ_0=keta_1a_2a_3. The drawing shows the actual eight states reached by these words. Dashed edges connect the two squares by changing the first bit. The other edges change one of the remaining bits. vfigaddresses headTwo different meanings of ``reach'…

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    a=(a_1,a_2,a_3)
a_3Use in source · 2 passages

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  • Use in source · monograph_atlas.tex, line 44

    vpage3One seed, eight addressesCYCLICITY DEPENDS ON THE GRAMMARTraditional edition: Proposition II.2.5. Start with ψ_0=ket000 and allow the three bit flip operators X_1,X_2,X_3. For a binary address a=(a_1,a_2,a_3), put W_a=X_1^a_1X_2^a_2X_3^a_3. W_aψ_0=keta_1a_2a_3. The drawing shows the actual eight states reached by these words. Dashed edges connect the two squares by changing the first bit. The other edges change one of the remaining bits. vfigaddresses headTwo different meanings of ``reach'…

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    a=(a_1,a_2,a_3)
\mathcal A_{ab}Use in source · 3 passages

Search aliases: A_ab mathcal

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  • Use in source · Read passage · 03_supplement_01.tex, line 189

    A constraint diagnostic that vanishes automatically. Section 12 defines the physical projector using the exact common kernel of the constraints. In finite dimensions this gives C_aP=0 for every a. Absorb the factor i and any structure coefficient into f_c, and write A_ab=C_aC_b-C_bC_a-∑_cf_cC_c. [Exact common-kernel compression] If C_cP=0 for every c, then A_abP=0, P A_abP=0. No idempotence or adjoint property of P is needed for this implication. Associativity gives A_abP=C_a(C_bP)-C_b(C_aP)-∑_c…

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    \mathcal A_{ab}=C_aC_b-C_bC_a-\sum_cf_cC_c.
    
\mathfrak A_{AB}Use in source · 3 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 1199

    At one finite level, let widehat C_A be a finite family of matrix constraints, with fixed scalar structure coefficients, and let Π^phys be the orthogonal projector onto their exact common kernel. If the classical constraint algebra has structure coefficients f_AB^ C, define the anomaly operator A_AB = [widehat C_A,widehat C_B] -i∑_C f_AB^ Cwidehat C_C. Its physical packet is Π^phys A_ABΠ^phys. In this exact finite setting, widehat C_CΠ^phys=0 for every C. Associativity gives A_ABΠ^phys=0, Π^phys…

    Exact mathematical passage
    
    \boxed{
    \mathfrak A_{AB}
    =
    [\widehat C_A,\widehat C_B]
    -i\sum_C f_{AB}^{\ \ C}\widehat C_C.
    }
    
\mathfrak A_{ab}Use in source · 2 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 2206

    If structure coefficients f_ab^phantomabc are prescribed, define the fixed structure anomaly A_ab = [C_a,C_b] - i∑_cf_ab^phantomabcC_c. Exact realization of the prescribed algebra is the stronger condition A_ab=0.

    Exact mathematical passage
    
    \mathfrak A_{ab}
    =
    [C_a,C_b]
    -\ii\sum_cf_{ab}^{\phantom{ab}c}C_c.
    
A_bUse in source · 1 passage

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  • Use in source · Read passage · 03_supplement_06.tex, line 49

    Smooth overlap maps and rank. The coordinate transition is g_ab(x)=A_b(x)B_a(x). It is smooth on U_a∩ U_b, agrees with the actual change between local homeomorphisms, and satisfies g_aa=I, g_bcg_ab=g_ac. A continuous linear equivalence between E_a and E_x also gives local constancy of fiber dimension. No single constant rank across disconnected components is assumed.

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    g_{ab}(x)=A_b(x)B_a(x)
A_{ba}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 12

    The elementary coordinate object is a complete family of orthogonal projectors P_aP_b=δ_abP_a, ∑_a∈ IP_a=I. Every vector has packet coordinates P_aψ. Every operator has transfer blocks A_ba=P_bAP_a. These identities are simple. Their value appears when the same coordinates are used across representation theory, circuits, channels, error correction, effective dynamics, and geometric limits.

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    A_{ba}=P_bAP_a.
    
A_iUse in source · 3 passages

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  • Use in source · Read passage · 03_supplement_02.tex, line 47

    Let F be an arbitrary finite set of factors and let D_i be a finite coordinate index for factor i. For matrix families A_i, define the coordinate tensor product on the product index space by T(A)(x,y)=∏_i∈ F A_i(x_i,y_i). The proof first establishes the laws for multiplication, identity, adjoints, and finite sums. These laws apply to any finite number of factors with the stated finite coordinate sets.

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    A_i
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  • Use in source · Read passage · 03_supplement_02.tex, line 54

    Suppose N>0 and each factor has a complete orthogonal self-adjoint projector family (P^(i)_j)_j∈ Z/N Z. For a fine address a:F→ Z/N Z, set Q_a= T(i↦ P^(i)_a_i), C_r=∑_∑_i a_i=rQ_a.

    Exact mathematical passage
    
     Q_a=\mathsf T\bigl(i\mapsto P^{(i)}_{a_i}\bigr),
     \qquad
     C_r=\sum_{\sum_i a_i=r}Q_a.
    
A_jUse in source · 2 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 1903

    [Reflection positive correlators] Fix a vector Ω and operators A_1,…,A_m. The matrix C_jk = ipA_jΩT^n_j+n_kA_kΩ is positive semidefinite.

    Exact mathematical passage
    
    C_{jk}
    =
    \ip{A_j\Omega}{T^{n_j+n_k}A_k\Omega}
    
a_jUse in source · 5 passages

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  • Use in source · Read passage · 03_supplement_02.tex, line 17

    0 · x≠ a. The seed is ψ_0=ket0. Define a translation operator by (T_a v)(x)=v(x-a). At position j, the local Pauli X is X_j=T_e_j, where e_j has a single nonzero binary coordinate. The formal circuit uses the identity when a_j=0 and X_j when a_j=1.

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    a_j=0
A_kUse in source · 2 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 1903

    [Reflection positive correlators] Fix a vector Ω and operators A_1,…,A_m. The matrix C_jk = ipA_jΩT^n_j+n_kA_kΩ is positive semidefinite.

    Exact mathematical passage
    
    C_{jk}
    =
    \ip{A_j\Omega}{T^{n_j+n_k}A_k\Omega}
    
A_mUse in source · 2 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 366

    [Tensor selection rule] If A_a has local charge q_a, then A_1⊗⋯⊗ A_m has total charge q_1+⋯+q_m.

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    A_1\otimes\cdots\otimes A_m
    
a_mUse in source · 7 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 389

    [Exact circuit path expansion] For source packet a_0 and target packet a_m, P_a_mUP_a_0 = ∑_a_1,…,a_m-1 P_a_mU_mP_a_m-1 ⋯ P_a_1U_1P_a_0. Summing over a_0 and a_m reconstructs U.

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    a_m
a_{m-1}Use in source · 3 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 390

    [Exact circuit path expansion] For source packet a_0 and target packet a_m, P_a_mUP_a_0 = ∑_a_1,…,a_m-1 P_a_mU_mP_a_m-1 ⋯ P_a_1U_1P_a_0. Summing over a_0 and a_m reconstructs U.

    Exact mathematical passage
    
    P_{a_m}UP_{a_0}
    =
    \sum_{a_1,\ldots,a_{m-1}}
    P_{a_m}U_mP_{a_{m-1}}
    \cdots
    P_{a_1}U_1P_{a_0}.
    
A_NUse in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 284

    ndomorphism-valued two-form P( d Pwedge d P)P. With the paper's scalar convention, its component is F_θϕ=- iTr (P[∂_θ P,∂_ϕ P]) =frac12sinθ. vfigbloch_curvature headA local frame gives the same answer Away from the south pole, use u_N=(cos(θ/2),e^ iϕsin(θ/2))^T. Then P=u_Nu_N^* and the scalar one-form is A_N=- i u_N^* d u_N=frac1-cosθ2 dϕ, d A_N=frac12sinθ dθwedge dϕ. Thus the curvature flux through the cap 0≤θ≤θ_0 is π(1-cosθ_0). At θ_0=π/3, it is exactly π/2. The latitude drawn in the plate il…

    Exact mathematical passage
    
    A_N=-\ii u_N^*\dd u_N=\frac{1-\cos\theta}{2}\,\dd\phi,
    \qquad \dd A_N=\frac12\sin\theta\,\dd\theta\wedge\dd\phi.
    
A_nUse in source · 10 passages

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  • Use in source · monograph_atlas.tex, line 795

    one matrices, and pointwise convergence gives C(j,k)=1+(1/2)^j+k. For times (0,1,2) and coefficients (1,-2,1), ∑_j,kv_jC_n(j,k)v_k=(1-q_n)^4≥0. This exact check illustrates how finite quadratic forms pass positivity to the limit. xfigtrace_topology headOperator norm does not preserve trace in growing rank On ℓ^2, let P_n select the first n coordinates and set A_n=P_n/n. Then normA_n=1/n→0 while Tr A_n=1 for every n. These positive trace-class operators show why the choice of topology matters. Th…

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    A_n=P_n/n
A_{ra}Use in source · 3 passages

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  • Use in source · Read passage · 03_supplement_05.tex, line 87

    Deriving the Gram matrix from recovery. Suppose a finite recovery that preserves trace corrects every operator supported on the code. To derive the Knill--Laflamme condition without assuming a syndrome decomposition, the proof expands the composite channel into the finite Kraus family A_ra=R_rE_aP. For every ambient matrix ρ, correction on the code implies ∑_r,a A_raρ A_ra^*=Pρ P. This equality on all matrices follows by applying correction to the sandwich supported on the code, Pρ P, using the …

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    A_{ra}=R_rE_aP.
    
A_{ra}^*Use in source · 1 passage

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  • Use in source · Read passage · 03_supplement_05.tex, line 91

    Deriving the Gram matrix from recovery Suppose a finite recovery that preserves trace corrects every operator supported on the code. To derive the Knill--Laflamme condition without assuming a syndrome decomposition, the proof expands the composite channel into the finite Kraus family A_ra=R_rE_aP. For every ambient matrix ρ, correction on the code implies ∑_r,a A_raρ A_ra^*=Pρ P. This equality on all matrices follows by applying correction to the sandwich supported on the code, Pρ P, using the p…

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    \sum_{r,a} A_{ra}\rho A_{ra}^*=P\rho P.
    
A_wUse in source · 4 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 802

    We call a recovery complete when it is a Kraus map R(X)=∑_jK_jXK_j^*, ∑_jK_j^*K_j=I. The family is exactly correctable when one such recovery works for every coherent error combination A_w=∑_aw_aE_a: for every w there is a real t_w≥0, independent of the logical input, such that PXP=X Longrightarrow R(A_wXA_w^*)=t_wX. The coefficient is an unnormalized weight. It is not necessarily a probability for an arbitrary matrix A_w.

    Exact mathematical passage
    A_w=\sum_aw_aE_a
A_w^*Use in source · 2 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 803

    We call a recovery complete when it is a Kraus map R(X)=∑_jK_jXK_j^*, ∑_jK_j^*K_j=I. The family is exactly correctable when one such recovery works for every coherent error combination A_w=∑_aw_aE_a: for every w there is a real t_w≥0, independent of the logical input, such that PXP=X Longrightarrow R(A_wXA_w^*)=t_wX. The coefficient is an unnormalized weight. It is not necessarily a probability for an arbitrary matrix A_w.

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    PXP=X\quad\Longrightarrow\quad
    \cR(A_wXA_w^*)=t_wX.
    
\mathfrak A_{\ell+1,ab}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 2279

    [Exact constraint transport] Assume C_ℓ+1,aR_ℓ=R_ℓ C_ℓ,a for every a. Then [C_ℓ+1,a,C_ℓ+1,b]R_ℓ = R_ℓ[C_ℓ,a,C_ℓ,b]. If the same structure coefficients are used at both levels, then A_ℓ+1,abR_ℓ = R_ℓ A_ℓ,ab. The isometry maps coarse physical states into fine physical states.

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    \mathfrak A_{\ell+1,ab}R_\ell
    =
    R_\ell\mathfrak A_{\ell,ab}.
    
\mathfrak A_{\ell,ab}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 2279

    [Exact constraint transport] Assume C_ℓ+1,aR_ℓ=R_ℓ C_ℓ,a for every a. Then [C_ℓ+1,a,C_ℓ+1,b]R_ℓ = R_ℓ[C_ℓ,a,C_ℓ,b]. If the same structure coefficients are used at both levels, then A_ℓ+1,abR_ℓ = R_ℓ A_ℓ,ab. The isometry maps coarse physical states into fine physical states.

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    \mathfrak A_{\ell+1,ab}R_\ell
    =
    R_\ell\mathfrak A_{\ell,ab}.
    
\AAUse in source · 2 passages

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  • Use in source · monograph_atlas.tex, line 26

    AA · Declared operator algebra · It specifies the available linear operations.

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    \AA
\Acal'Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 863

    [Nonabelian packet connection] The one form with matrix values A=V^* d V is skew adjoint. Under a frame change V'=VG, where G(x)∈ U(r), A' = G^* A G+G^* d G. Its curvature F= d A+ Awedge A satisfies F=V^*( d Pwedge d P)V.

    Exact mathematical passage
    
    \Acal'
    =
    G^*\Acal G+G^*\dd G.
    
\Acal^*Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 879

    Differentiate V^*V=I to obtain A^*=- A. The gauge transformation law follows by differentiating VG. Since P=VV^* and (I-P) d V= d P V, direct expansion gives d A+ Awedge A = d V^*(I-P)wedge d V = V^*( d Pwedge d P)V.

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    \Acal^*=-\Acal
\Acal_{\Pcal}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 999

    [Dephasing as conditional expectation] The map D_ P is completely positive, trace preserving, unital, and idempotent. It is the Hilbert Schmidt orthogonal projection onto the block diagonal algebra A_ P = {X:[X,P_a]=0 for every a}. In particular, norm D_ P(X)_HS ≤ normX_HS.

    Exact mathematical passage
    
    \Acal_{\Pcal}
    =
    \{X:[X,P_a]=0\text{ for every }a\}.
    
\AdUse in source · 4 passages

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\Ad_SUse in source · 3 passages

Search aliases: Ad_S Ad operatorname

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\Ad_{U(g)}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 1166

    Let Ω=∑_iketi⊗keti. Then J(Φ)=(Φ⊗id)(ketΩbraΩ). The vector Ω is invariant under U⊗overline U. Covariance therefore implies the displayed Choi invariance. Conversely, the displayed transformation is the Choi matrix of Ad_U(g)∘Φ∘Ad_U(g)^*. The Choi correspondence is injective, so invariance implies that this map equals Φ, which is covariance.

    Exact mathematical passage
    
    \Ad_{U(g)}\circ\Phi\circ\Ad_{U(g)^*}.
    
\Ad_{U(g)^*}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 1166

    Let Ω=∑_iketi⊗keti. Then J(Φ)=(Φ⊗id)(ketΩbraΩ). The vector Ω is invariant under U⊗overline U. Covariance therefore implies the displayed Choi invariance. Conversely, the displayed transformation is the Choi matrix of Ad_U(g)∘Φ∘Ad_U(g)^*. The Choi correspondence is injective, so invariance implies that this map equals Φ, which is covariance.

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    \Ad_{U(g)}\circ\Phi\circ\Ad_{U(g)^*}.
    
\bm bUse in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 920

    The Pauli identity ( a·σ)( b·σ) =( a· b)I + i( a× b)·σ gives - iTr(P[∂_θ P,∂_ϕ P]) =frac12 n· (∂_θ n×∂_ϕ n) =frac12sinθ. Integrating the displayed curvature over the sphere and applying the stated normalization gives one.

    Exact mathematical passage
    
    (\bm a\cdot\bm\sigma)(\bm b\cdot\bm\sigma)
    =(\bm a\cdot\bm b)I
    +\ii(\bm a\times\bm b)\cdot\bm\sigma
    
B^2Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 1640

    [Low energy expansion] Assume D is invertible and abs znormD^-1<1. Then Σ(z) =- ∑_n=0^∞ z^nBD^-n-1B^* with norm convergence. In particular, F_P(z) = z-A+BD^-1B^*+O(abs znorm B^2normD^-1^2).

    Exact mathematical passage
    
    F_P(z)
    =
     z-A+BD^{-1}B^*+O\bigl(\abs z\norm B^2\norm{D^{-1}}^2\bigr).
    
b_a^{\phantom a c}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 2241

    [Invariance of the physical space] Let H=H^*. Suppose [H,C_a] = ∑_cb_a^phantom a cC_c for every a. Then H preserves H_phys, and so does e^- i tH for every real t.

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    [H,C_a]
    =
    \sum_cb_a^{\phantom a c}C_c
    
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  • Use in source · Read passage · 03_supplement_02.tex, line 71

    Expanding the finite product of sums gives T(A) T(B)= T(i↦ A_iB_i). Consequently, if two fine addresses differ in any coordinate, the corresponding product contains a zero factor. If the addresses agree, the product is the same fine projector. The adjoint passes through the finite coordinate product, so Q_a^*=Q_a. Summing over all address functions and using the same expansion yields ∑_a Q_a= T(i↦∑_jP^(i)_j)=I. A separate algebraic regrouping theorem applies to any finite orthogonal family and a…

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     \mathsf T(A)\mathsf T(B)=\mathsf T(i\mapsto A_iB_i).
    
B_rUse in source · 5 passages

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  • Use in source · Read passage · 03_supplement_05.tex, line 49

    Define the transformed errors by an actual finite sum, B_r=∑_a U_arF_a. The formal module proves the identities B_rP=B_r, B_r^*B_s=δ_rsλ_rP, ∑_rB_rρ B_r^*=∑_aF_aρ F_a^*. For ρ supported on the code, the restricted and unrestricted error sums are equal. Thus the unitary change of error coordinates preserves the actual channel on the code.

    Exact mathematical passage
    
    B_r=\sum_a U_{ar}F_a.
    
B_r^*Use in source · 2 passages

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  • Use in source · Read passage · 03_supplement_05.tex, line 53

    Define the transformed errors by an actual finite sum, B_r=∑_a U_arF_a. The formal module proves the identities B_rP=B_r, B_r^*B_s=δ_rsλ_rP, ∑_rB_rρ B_r^*=∑_aF_aρ F_a^*. For ρ supported on the code, the restricted and unrestricted error sums are equal. Thus the unitary change of error coordinates preserves the actual channel on the code.

    Exact mathematical passage
    
    B_rP=B_r,\qquad B_r^*B_s=\delta_{rs}\lambda_rP,
    \qquad \sum_rB_r\rho B_r^*=\sum_aF_a\rho F_a^*.
    
B_sUse in source · 1 passage

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  • Use in source · Read passage · 03_supplement_05.tex, line 53

    Define the transformed errors by an actual finite sum, B_r=∑_a U_arF_a. The formal module proves the identities B_rP=B_r, B_r^*B_s=δ_rsλ_rP, ∑_rB_rρ B_r^*=∑_aF_aρ F_a^*. For ρ supported on the code, the restricted and unrestricted error sums are equal. Thus the unitary change of error coordinates preserves the actual channel on the code.

    Exact mathematical passage
    
    B_rP=B_r,\qquad B_r^*B_s=\delta_{rs}\lambda_rP,
    \qquad \sum_rB_r\rho B_r^*=\sum_aF_a\rho F_a^*.
    
\bar bUse in source · 1 passage

Search aliases: bar b bar

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  • Use in source · monograph_atlas.tex, line 156

    ity. Starting from ket0, there are two resolved paths to output ket1. Their signed products are bra1H_rm Hadket0bra0H_rm Hadket0=frac12, bra1H_rm Hadket1bra1H_rm Hadket0=-frac12. Their sum is zero. Squaring each separately gives a different answer. vfiginterference headWhere the missing term goes For path amplitudes a,b, the outcome probability is |a+b|^2=|a|^2+|b|^2+2Re(abar b). Here the last term is -1/2, canceling the first two terms. The path picture retains this information only if its edge…

    Exact mathematical passage
    |a+b|^2=|a|^2+|b|^2+2\Re(a\bar b)
\bbCUse in source · 11 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 79

    Let a finite-dimensional unital *-subalgebra of operators act in its standard multiplicity form A ≅ ⊕_i=1^r (M_d_i( C)⊗ I_m_i) on H ≅ ⊕_i=1^r ( C^d_i⊗ C^m_i). Here every d_i is a positive integer and every multiplicity m_i is a nonnegative integer. An empty block family represents the zero space and has seed rank zero. The maximum over an empty block family is also assigned the value zero. A vector ψ_i∈ C^d_i⊗ C^m_i is identified with a d_i× m_i coefficient matrix C_i.

    Exact mathematical passage
    
    \cA
    \cong
    \bigoplus_{i=1}^r
    \left(M_{d_i}(\bbC)\otimes I_{m_i}\right)
    
\bbC^dUse in source · 1 passage

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  • Use in source · Read passage · 01_finite_core.tex, line 95

    [Orbit dimension of one quantum seed] For integers d≥1 and m≥0, consider the action of M_d( C)⊗ I_m on C^d⊗ C^m. Let C be the coefficient matrix of a vector ψ. Then dimspan{(A⊗ I_m)ψ:A∈ M_d( C)} =d rank C. The seed is cyclic if and only if rank C=m, which is possible only when m≤ d.

    Exact mathematical passage
    \bbC^d\otimes\bbC^m
\bbC^{d_i}Use in source · 3 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 86

    Let a finite-dimensional unital *-subalgebra of operators act in its standard multiplicity form A ≅ ⊕_i=1^r (M_d_i( C)⊗ I_m_i) on H ≅ ⊕_i=1^r ( C^d_i⊗ C^m_i). Here every d_i is a positive integer and every multiplicity m_i is a nonnegative integer. An empty block family represents the zero space and has seed rank zero. The maximum over an empty block family is also assigned the value zero. A vector ψ_i∈ C^d_i⊗ C^m_i is identified with a d_i× m_i coefficient matrix C_i.

    Exact mathematical passage
    
    \cH
    \cong
    \bigoplus_{i=1}^r
    \left(\bbC^{d_i}\otimes\bbC^{m_i}\right).
    
\bbC^mUse in source · 1 passage

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  • Use in source · Read passage · 01_finite_core.tex, line 95

    [Orbit dimension of one quantum seed] For integers d≥1 and m≥0, consider the action of M_d( C)⊗ I_m on C^d⊗ C^m. Let C be the coefficient matrix of a vector ψ. Then dimspan{(A⊗ I_m)ψ:A∈ M_d( C)} =d rank C. The seed is cyclic if and only if rank C=m, which is possible only when m≤ d.

    Exact mathematical passage
    \bbC^d\otimes\bbC^m
\bbC^{m_i}Use in source · 6 passages

Search aliases: bbC^m_i C^m_i bbC mathbb

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  • Use in source · Read passage · 01_finite_core.tex, line 86

    Let a finite-dimensional unital *-subalgebra of operators act in its standard multiplicity form A ≅ ⊕_i=1^r (M_d_i( C)⊗ I_m_i) on H ≅ ⊕_i=1^r ( C^d_i⊗ C^m_i). Here every d_i is a positive integer and every multiplicity m_i is a nonnegative integer. An empty block family represents the zero space and has seed rank zero. The maximum over an empty block family is also assigned the value zero. A vector ψ_i∈ C^d_i⊗ C^m_i is identified with a d_i× m_i coefficient matrix C_i.

    Exact mathematical passage
    
    \cH
    \cong
    \bigoplus_{i=1}^r
    \left(\bbC^{d_i}\otimes\bbC^{m_i}\right).
    
\bbRUse in source · 2 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 573

    [Projected connection] Let M be a smooth finite-dimensional real manifold without boundary, let V be a finite-dimensional real normed vector space, and let P:M→End_ R(V) be smooth with P(x)^2=P(x). In the quantum application, V is the underlying real space of a finite complex Hilbert space and P is an orthogonal complex-linear projector.

    Exact mathematical passage
    P:M\to\operatorname{End}_{\bbR}(V)
\bbZUse in source · 1 passage

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  • Use in source · Read passage · 01_finite_core.tex, line 246

    [Tensor/polyphase refinement] For each residue r∈ Z/N Z, define P_r^coarse = ∑_j_1+⋯+j_m≡ rpmod N P^(1)_j_1⊗⋯⊗ P^(m)_j_m. Then the P_r^coarse are complete orthogonal projectors, and every coarse packet is the exact sum of its fine descendants.

    Exact mathematical passage
    r\in\bbZ/N\bbZ
\bmodUse in source · 2 passages

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  • Use in source · monograph_atlas.tex, line 92

    vpage6Four phases resolve a cyclic shiftCHARACTER PROJECTORS YOU CAN MULTIPLYTraditional edition: Corollary II.3.3. On four sites, let Sket k=ketk+1bmod4 and let ω= i. The character projectors are the exact matrices P_j=frac14∑_r=0^3 i^-jrS^r, v_j(k)=frac12 i^-jk, P_j=v_jv_j^*. All entries belong to the Gaussian rationals. Thus no approximation to a root of unity is needed in this model. vfigcyclic_four headReading the columns Each column v_j is a normalized wave around the four sites. Advancing…

    Exact mathematical passage
    S\ket k=\ket{k+1\bmod4}
\braUse in source · 21 passages

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  • Use in source · monograph_atlas.tex, line 108

    vpage7A coarse packet can still contain coherenceTENSOR REFINEMENT BY TOTAL PARITYTraditional edition: Theorem II.3.7, Corollary II.3.8. For three qubits, the eight fine projectors are P_a=ket abra a. Grouping addresses according to the parity of their Hamming weight gives P_rm even=P_000+P_011+P_101+P_110 =fracI+Z⊗ Z⊗ Z2, P_rm odd=I-P_rm even. This is a sum of subspaces, not an averaging of their coordinates. The rank-four even packet retains all complex amplitudes on its four children. vfigpar…

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    P_a=\ket a\bra a
\mathbb CUse in source · 2 passages

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  • Use in source · Read passage · monograph_examples.tex, line 3

    Three exact finite models. addcontentslinetocsectionThree exact finite models A seed remembers multiplicity support. For M_2( C)⊗ I_3, a coefficient matrix with rank one generates an orbit of dimension two. A matrix of rank two generates an orbit of dimension four. Neither single seed spans the full space of dimension six, because a 2×3 matrix cannot have rank three. Two seeds can nevertheless cover all three multiplicity coordinates together. The example illustrates the finite seed rank formula…

    Exact mathematical passage
    M_2(\mathbb C)\otimes I_3
c^*Use in source · 1 passage

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  • Use in source · Read passage · 03_supplement_05.tex, line 175

    For E(c)=∑_a c_aE_a, finite-sum expansion gives R(E(c)ρ E(c)^*) =(∑_a,bc_aoverlinec_bC_ba)ρ =(c^*Cc)ρ. The formula with a double sum is the literal checked conclusion. The final notation as a quadratic form follows by renaming finite indices. It is not restricted to orthogonal errors or real coefficients.

    Exact mathematical passage
    
    \mathcal R\bigl(E(c)\rho E(c)^*\bigr)
    =\left(\sum_{a,b}c_a\overline{c_b}C_{ba}\right)\rho
    =(c^*Cc)\rho.
    
C^2Use in source · 2 passages

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  • Use in source · Read passage · 03_supplement_04.tex, line 49

    Actual projected differentiation and curvature. Let E,F be real normed spaces. Let P:E→ L(F,F) be differentiable with P(x)^2=P(x) for every x. Let s:E→ F be C^2 with P(x)s(x)=s(x), and let X,Y:E→ E be differentiable vector fields. The checked connection is the actual expression ∇_Xs(x)=P(x) Ds(x)[X(x)]. It is proved to preserve the range condition. It is linear in the vector field direction and obeys the scalar Leibniz rule ∇_X(cs)=Dc[X] s+c∇_Xs for differentiable real scalar functions c. No dif…

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    C^2
\mathbb C^2Use in source · 1 passage

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  • Use in source · Read passage · monograph_examples.tex, line 17

    model uses two coordinates to illustrate block inversion. Both the eliminated block and the full operator are invertible, and the plotted values are exact fractions. The example shows why direct compression and resolvent elimination give different results. Normalization changes the map. Let P=|0⟩⟨0| on C^2 and Z=diag(1,-1). The normalized Kraus family sqrt3/4 I, sqrt1/4 Z satisfies ∑_j K_j^*K_j=I and maps P to P. The unnormalized family sqrt3 I, Z satisfies ∑_j E_j^*E_j=4I and maps P to 4P. The …

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    \mathbb C^2
\C^nUse in source · 1 passage

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  • Use in source · Read passage · 03_supplement_05.tex, line 2

    The precise finite channel statement. Let H= C^n be a finite coordinate space and let P=P^*=P^2. A matrix is code supported when Pρ P=ρ. For a finite family of square matrices E_a, put N_E(ρ)=∑_a E_aρ E_a^*. The input channel normalization is the actual matrix identity ∑_a E_a^*E_a=I. A finite Kraus recovery has the form R(σ)=∑_r R_rσ R_r^*, with ∑_rR_r^*R_r=I. This representation, together with the checked amplification results, provides complete positivity and trace preservation on the entire …

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    \mathcal H=\C^n
C_1Use in source · 14 passages

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  • Use in source · monograph_atlas.tex, line 75

    vpage5Why one seed is not always enoughAN EXACT MULTIPLICITY LOWER BOUNDTraditional edition: Theorem II.2.3. Consider M_2( C)⊗ I_3 acting on C^2⊗ C^3. A seed is a 2×3 coefficient matrix. Its two rows span at most two directions in the three-dimensional multiplicity factor. Therefore no single seed is cyclic for this algebra. C_1=mat1 · 0 · 0 0 · 1 · 0, C_2=mat0 · 0 · 1 0 · 0 · 0. These two matrices provide a complete set of row directions. Their individual orbit dimensions are four and two, and …

    Exact mathematical passage
    
    C_1=\mat{1&0&0\\0&1&0},\qquad
    C_2=\mat{0&0&1\\0&0&0}.
    
C_2Use in source · 11 passages

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  • Use in source · monograph_atlas.tex, line 75

    vpage5Why one seed is not always enoughAN EXACT MULTIPLICITY LOWER BOUNDTraditional edition: Theorem II.2.3. Consider M_2( C)⊗ I_3 acting on C^2⊗ C^3. A seed is a 2×3 coefficient matrix. Its two rows span at most two directions in the three-dimensional multiplicity factor. Therefore no single seed is cyclic for this algebra. C_1=mat1 · 0 · 0 0 · 1 · 0, C_2=mat0 · 0 · 1 0 · 0 · 0. These two matrices provide a complete set of row directions. Their individual orbit dimensions are four and two, and …

    Exact mathematical passage
    
    C_1=\mat{1&0&0\\0&1&0},\qquad
    C_2=\mat{0&0&1\\0&0&0}.
    
c_aUse in source · 2 passages

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  • Use in source · Read passage · 03_supplement_05.tex, line 174

    For E(c)=∑_a c_aE_a, finite-sum expansion gives R(E(c)ρ E(c)^*) =(∑_a,bc_aoverlinec_bC_ba)ρ =(c^*Cc)ρ. The formula with a double sum is the literal checked conclusion. The final notation as a quadratic form follows by renaming finite indices. It is not restricted to orthogonal errors or real coefficients.

    Exact mathematical passage
    E(c)=\sum_a c_aE_a
C_{ab}Use in source · 3 passages

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  • Use in source · Read passage · 03_supplement_05.tex, line 14

    Necessary and sufficient conditions. Under the stated normalization, the following equivalence is proved: ∃ R of the above finite Kraus form, [-2pt] R N_E(ρ)=ρ for every ρsucceq0, Trρ=1, Pρ P=ρ Longleftrightarrow ∃ Csucceq0, PE_a^*E_bP=C_abP for all a,b. The statement applies throughout the code space. The formalization separately proves equivalence with correction of every complex matrix supported on the code. It also proves preservation with arbitrary finite reference systems, as detailed in t…

    Exact mathematical passage
    
    \boxed{\begin{gathered}
    \exists\,\mathcal R\text{ of the above finite Kraus form,}\\[-2pt]
    \mathcal R\mathcal N_E(\rho)=\rho
    \quad\text{for every }\rho\succeq0,\ \Tr\rho=1,\ P\rho P=\rho
    \end{gathered}}
    \quad\Longleftrightarrow\quad
    \boxed{\begin{gathered}
    \exists C\succeq0,\\
    PE_a^*E_bP=C_{ab}P\quad\text{for all }a,b.
    \end{gathered}}
    
c_{ab}Use in source · 8 passages

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  • Use in source · monograph_atlas.tex, line 598

    vpage32Null Gram directions are removed before recoveryA TOTAL CHANNEL FROM SINGULAR ERROR DATATraditional edition: Theorem II.8.3, Theorem II.8.4. Let HH= C^3, with nonzero code projector P=diag(1,1,0). On the code use the error family E_1=(3/5)P, E_2=(4/5)P, and E_3=0. Its Knill--Laflamme Gram matrix is c=frac125mat9 · 12 · 0 12 · 16 · 0 0 · 0 · 0, PE_a^*E_bP=c_abP. The errors are redundant rather than three distinct syndromes. A real unitary change of error coordinates gives W=mat3/5 · 4/5 · …

    Exact mathematical passage
    
    c=\frac1{25}\mat{9&12&0\\12&16&0\\0&0&0},
    \qquad PE_a^*E_bP=c_{ab}P.
    
C_{ba}Use in source · 2 passages

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  • Use in source · Read passage · 03_supplement_05.tex, line 169

    Cross terms for the original errors. For arbitrary positive Gram data, the same recovery satisfies R(E_aρ E_b^*)=C_baρ (Pρ P=ρ). The index order ba is intentional: the defining Gram relation is PE_a^*E_bP=C_abP. The proof first derives scalar corrected Kraus composites for the constructed recovery and then uses its trace-preserving completeness to identify the original Gram entries.

    Exact mathematical passage
    
    \boxed{\mathcal R(E_a\rho E_b^*)=C_{ba}\rho\qquad(P\rho P=\rho).}
    
C_iUse in source · 1 passage

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  • Use in source · Read passage · 01_finite_core.tex, line 92

    lus_i=1^r ( C^d_i⊗ C^m_i). Here every d_i is a positive integer and every multiplicity m_i is a nonnegative integer. An empty block family represents the zero space and has seed rank zero. The maximum over an empty block family is also assigned the value zero. A vector ψ_i∈ C^d_i⊗ C^m_i is identified with a d_i× m_i coefficient matrix C_i.

    Exact mathematical passage
    C_i
C_{ij}Use in source · 2 passages

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  • Use in source · Read passage · 03_supplement_03.tex, line 45

    Schmidt rank and the reduced state. Use coordinates ψ_ij in the standard product basis and let C_ij=ψ_ij. An explicit linear equivalence identifies the state vector on the product index set with its coefficient matrix. The implementation checks the actual Kronecker action: coeff((A⊗ I_B)ψ)=AC. It also proves that the transported matrix orbit equals the span of the state vectors obtained by this Kronecker action. The dimension formula therefore applies to the physical local action on the state sp…

    Exact mathematical passage
    C_{ij}=\psi_{ij}
c_{ja}Use in source · 1 passage

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  • Use in source · Read passage · 03_supplement_05.tex, line 183

    Every normalized channel in the same span. Suppose F_j=∑_a c_jaE_a and ∑_jF_j^*F_j=I. The decoder is not reconstructed for the F_j. Summing the coherent identities gives a scalar multiple qρ. Trace preservation of both the F channel and the recovery forces q=1 on a nonzero code. The proof uses positivity of P to justify cancellation of its trace and handles P=0 separately. Therefore R(∑_jF_jρ F_j^*)=ρ. This is pathData.recovery_span_channel, a quantified statement over arbitrary finite F familie…

    Exact mathematical passage
    F_j=\sum_a c_{ja}E_a
C_{jk}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 1903

    [Reflection positive correlators] Fix a vector Ω and operators A_1,…,A_m. The matrix C_jk = ipA_jΩT^n_j+n_kA_kΩ is positive semidefinite.

    Exact mathematical passage
    
    C_{jk}
    =
    \ip{A_j\Omega}{T^{n_j+n_k}A_k\Omega}
    
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  • Use in source · Read passage · 03_supplement_03.tex, line 17

    Several seeds: both necessity and construction. Continue under the assumption above that the number of rows is positive. For seeds C_1,…,C_k, generation means the concrete statement ∀ X∈ M_d× m( C), ∃ A_1,…,A_k∈ M_d( C): X=∑_a=1^k A_aC_a. Stack the C_a vertically into a kd× m matrix D. The source identifies the action on the stacked matrix and proves the equivalence the seeds generate Longleftrightarrow rank D=m. Thus m≤ kd is necessary. It is sufficient as well: embed the m coordinate columns i…

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    C_1,\ldots,C_k
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  • Use in source · Read passage · 02_strengthened.tex, line 1880

    [Finite reflection positivity] For vectors v_1,…,v_m∈ H and nonnegative integers n_1,…,n_m, the matrix G_jk=ipv_jT^n_j+n_kv_k is positive semidefinite. Equivalently, ∑_j,koverlinec_jc_k ipv_jT^n_j+n_kv_k ≥0 for every c∈ C^m.

    Exact mathematical passage
    
    \sum_{j,k}\overline{c_j}c_k
    \ip{v_j}{T^{n_j+n_k}v_k}
    \geq0
    
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  • Use in source · Read passage · 02_strengthened.tex, line 2174

    Let C_1,…,C_m be self adjoint constraint operators on a finite dimensional Hilbert space. The distinction between constraint action and constraint closure is standard in constrained Hamiltonian theory [source reference]. Write c=span_ C{C_1,…,C_m} ⊆End( H).

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    C_1,\ldots,C_m
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  • Use in source · monograph_atlas.tex, line 788

    vpage40Choose the topology that preserves the quantityREFLECTION GRAMS, TRACES, AND FINAL SCOPETraditional edition: Theorem II.13.6, Theorem II.13.8, Section II.14. Let q_n=1/2+2^-(n+2) and define the scalar reflected kernel C_n(j,k)=1+q_n^j+k on nonnegative integers. Each finite Gram matrix is a sum of two positive rank-one matrices, and pointwise convergence gives C(j,k)=1+(1/2)^j+k. For times (0,1,2) and coefficients (1,-2,1), ∑_j,kv_jC_n(j,k)v_k=(1-q_n)^4≥0. This exact check illustrates how …

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    C_n(j,k)=1+q_n^{j+k}
C_{n,a}Use in source · 2 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 2491

    [Constraint closure under norm convergence] Let C_n,a→ C_a in norm for every a, and fix structure coefficients f_ab^phantomabc. If norm [C_n,a,C_n,b] - i∑_cf_ab^phantomabcC_n,c ⟶0, then [C_a,C_b] = i∑_cf_ab^phantomabcC_c.

    Exact mathematical passage
    C_{n,a}\to C_a
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  • Use in source · Read passage · 02_strengthened.tex, line 2492

    [Constraint closure under norm convergence] Let C_n,a→ C_a in norm for every a, and fix structure coefficients f_ab^phantomabc. If norm [C_n,a,C_n,b] - i∑_cf_ab^phantomabcC_n,c ⟶0, then [C_a,C_b] = i∑_cf_ab^phantomabcC_c.

    Exact mathematical passage
    
    \norm{
    [C_{n,a},C_{n,b}]
    -\ii\sum_cf_{ab}^{\phantom{ab}c}C_{n,c}
    }
    \longrightarrow0,
    
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  • Use in source · Read passage · 02_strengthened.tex, line 2492

    [Constraint closure under norm convergence] Let C_n,a→ C_a in norm for every a, and fix structure coefficients f_ab^phantomabc. If norm [C_n,a,C_n,b] - i∑_cf_ab^phantomabcC_n,c ⟶0, then [C_a,C_b] = i∑_cf_ab^phantomabcC_c.

    Exact mathematical passage
    
    \norm{
    [C_{n,a},C_{n,b}]
    -\ii\sum_cf_{ab}^{\phantom{ab}c}C_{n,c}
    }
    \longrightarrow0,
    
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  • Use in source · Read passage · 03_supplement_02.tex, line 54

    Suppose N>0 and each factor has a complete orthogonal self-adjoint projector family (P^(i)_j)_j∈ Z/N Z. For a fine address a:F→ Z/N Z, set Q_a= T(i↦ P^(i)_a_i), C_r=∑_∑_i a_i=rQ_a.

    Exact mathematical passage
    
     Q_a=\mathsf T\bigl(i\mapsto P^{(i)}_{a_i}\bigr),
     \qquad
     C_r=\sum_{\sum_i a_i=r}Q_a.
    
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  • Use in source · Read passage · 03_supplement_02.tex, line 62

    The fine and coarse families are complete orthogonal self-adjoint projector systems. In particular, C_rC_s=δ_rsC_r, ∑_r C_r=I, C_r^*=C_r. Each coarse projector is exactly the displayed sum of its fine descendants.

    Exact mathematical passage
    
     C_rC_s=\delta_{rs}C_r,\qquad
     \sum_r C_r=I,\qquad C_r^*=C_r.
    
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  • Use in source · Read passage · 03_supplement_02.tex, line 62

    The fine and coarse families are complete orthogonal self-adjoint projector systems. In particular, C_rC_s=δ_rsC_r, ∑_r C_r=I, C_r^*=C_r. Each coarse projector is exactly the displayed sum of its fine descendants.

    Exact mathematical passage
    
     C_rC_s=\delta_{rs}C_r,\qquad
     \sum_r C_r=I,\qquad C_r^*=C_r.
    
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  • Use in source · Read passage · 02_strengthened.tex, line 812

    em[Convergence of short packet rotations] Let (P_a(t)) be twice continuously differentiable on [0,T]. For a partition 0=t_0<t_1<⋯<t_n=T, let W_π = U( P(t_n), P(t_n-1)) ⋯ U( P(t_1), P(t_0)). For sufficiently fine partitions the factors are defined, and normW_π-W(T) ≤ C_Tabsπ for a constant depending on the packet path but not on the partition. Here the size of the partition is measured by its mesh, which is the length of its largest subinterval.

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    \norm{W_\pi-W(T)}
    \leq
    C_T\abs{\pi}
    
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  • Use in source · monograph_atlas.tex, line 747

    vpage38Transport constraints without hiding closureTHE IMAGE OF AN ISOMETRY IS NOT THE WHOLE LEVELTraditional edition: Theorem II.12.2, Theorem II.12.5, Proposition II.12.6. On C^3= Cket0⊕ C^2, use C_a=0⊕σ_a for a=x,y,z. The common kernel is Cket0, and the full algebra closes: [C_x,C_y]=2 i C_z, [C_y,C_z]=2 i C_x, [C_z,C_x]=2 i C_y. These are uncompressed identities. They supply an actual closure test in the quotient by the constraint span, unlike the automatic compressed zero on the physical ke…

    Exact mathematical passage
    
    [C_x,C_y]=2\ii C_z,\qquad[C_y,C_z]=2\ii C_x,\qquad[C_z,C_x]=2\ii C_y.
    
C_yUse in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 747

    vpage38Transport constraints without hiding closureTHE IMAGE OF AN ISOMETRY IS NOT THE WHOLE LEVELTraditional edition: Theorem II.12.2, Theorem II.12.5, Proposition II.12.6. On C^3= Cket0⊕ C^2, use C_a=0⊕σ_a for a=x,y,z. The common kernel is Cket0, and the full algebra closes: [C_x,C_y]=2 i C_z, [C_y,C_z]=2 i C_x, [C_z,C_x]=2 i C_y. These are uncompressed identities. They supply an actual closure test in the quotient by the constraint span, unlike the automatic compressed zero on the physical ke…

    Exact mathematical passage
    
    [C_x,C_y]=2\ii C_z,\qquad[C_y,C_z]=2\ii C_x,\qquad[C_z,C_x]=2\ii C_y.
    
C_zUse in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 747

    vpage38Transport constraints without hiding closureTHE IMAGE OF AN ISOMETRY IS NOT THE WHOLE LEVELTraditional edition: Theorem II.12.2, Theorem II.12.5, Proposition II.12.6. On C^3= Cket0⊕ C^2, use C_a=0⊕σ_a for a=x,y,z. The common kernel is Cket0, and the full algebra closes: [C_x,C_y]=2 i C_z, [C_y,C_z]=2 i C_x, [C_z,C_x]=2 i C_y. These are uncompressed identities. They supply an actual closure test in the quotient by the constraint span, unlike the automatic compressed zero on the physical ke…

    Exact mathematical passage
    
    [C_x,C_y]=2\ii C_z,\qquad[C_y,C_z]=2\ii C_x,\qquad[C_z,C_x]=2\ii C_y.
    
C_\psiUse in source · 10 passages

Search aliases: C_ψ psi

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  • Use in source · Read passage · 02_strengthened.tex, line 120

    [Orbit dimension of one seed] For integers d≥1, m≥0, and the action of M_d( C)⊗ I_m on C^d⊗ C^m, let C_ψ be the coefficient matrix of ψ. Then dimspan{(A⊗ I_m)ψ:A∈ M_d( C)} = drank C_ψ. The vector is cyclic exactly when rank C_ψ=m.

    Exact mathematical passage
    C_\psi
C_\ellUse in source · 7 passages

Search aliases: C_ℓ ell

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  • Use in source · Read passage · 01_finite_core.tex, line 1003

    At resolution ℓ, define Q_ℓ = ( A_ℓ, H_ℓ, D_ℓ, {P_ℓ,α}, E_ℓ, C_ℓ, Π_ℓ^phys, T_ℓ ). In order, the entries specify the observable algebra, Hilbert space, geometric or Dirac-type operator, packet projectors, embedding into the fine space, reconstruction onto the coarse space, physical constraint projector, and transfer operator. The maps have types E_ℓ: H_ℓ→ H_ℓ+1 and C_ℓ: H_ℓ+1→ H_ℓ. The left inverse relation C_ℓ E_ℓ=I alone does not imply C_ℓ=E_ℓ^* or make the embedding isometric.

    Exact mathematical passage
    
    \boxed{
    \mathfrak Q_\ell
    =
    \left(
    \cA_\ell,
    \cH_\ell,
    D_\ell,
    \{P_{\ell,\alpha}\},
    E_\ell,
    C_\ell,
    \Pi_\ell^{\mathrm{phys}},
    T_\ell
    \right).
    }
    
C_{\ell+1,a}Use in source · 10 passages

Search aliases: C_ℓ+1,a ell

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  • Use in source · Read passage · 02_strengthened.tex, line 2261

    Let ( H_ℓ,C_ℓ,a) and ( H_ℓ+1,C_ℓ+1,a) be two levels, and let R_ℓ: H_ℓ⟶ H_ℓ+1 be an isometry.

    Exact mathematical passage
    (\Hcal_{\ell+1},C_{\ell+1,a})
C_{\ell+1,b}Use in source · 3 passages

Search aliases: C_ℓ+1,b ell

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  • Use in source · Read passage · 02_strengthened.tex, line 2273

    [Exact constraint transport] Assume C_ℓ+1,aR_ℓ=R_ℓ C_ℓ,a for every a. Then [C_ℓ+1,a,C_ℓ+1,b]R_ℓ = R_ℓ[C_ℓ,a,C_ℓ,b]. If the same structure coefficients are used at both levels, then A_ℓ+1,abR_ℓ = R_ℓ A_ℓ,ab. The isometry maps coarse physical states into fine physical states.

    Exact mathematical passage
    
    [C_{\ell+1,a},C_{\ell+1,b}]R_\ell
    =
    R_\ell[C_{\ell,a},C_{\ell,b}].
    
C_{\ell,a}Use in source · 10 passages

Search aliases: C_ℓ,a ell

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  • Use in source · Read passage · 02_strengthened.tex, line 2261

    Let ( H_ℓ,C_ℓ,a) and ( H_ℓ+1,C_ℓ+1,a) be two levels, and let R_ℓ: H_ℓ⟶ H_ℓ+1 be an isometry.

    Exact mathematical passage
    (\Hcal_\ell,C_{\ell,a})
C_{\ell,b}Use in source · 3 passages

Search aliases: C_ℓ,b ell

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  • Use in source · Read passage · 02_strengthened.tex, line 2273

    [Exact constraint transport] Assume C_ℓ+1,aR_ℓ=R_ℓ C_ℓ,a for every a. Then [C_ℓ+1,a,C_ℓ+1,b]R_ℓ = R_ℓ[C_ℓ,a,C_ℓ,b]. If the same structure coefficients are used at both levels, then A_ℓ+1,abR_ℓ = R_ℓ A_ℓ,ab. The isometry maps coarse physical states into fine physical states.

    Exact mathematical passage
    
    [C_{\ell+1,a},C_{\ell+1,b}]R_\ell
    =
    R_\ell[C_{\ell,a},C_{\ell,b}].
    
\cAUse in source · 5 passages

Search aliases: cA A mathcal

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  • Use in source · Read passage · 01_finite_core.tex, line 79

    Let a finite-dimensional unital *-subalgebra of operators act in its standard multiplicity form A ≅ ⊕_i=1^r (M_d_i( C)⊗ I_m_i) on H ≅ ⊕_i=1^r ( C^d_i⊗ C^m_i). Here every d_i is a positive integer and every multiplicity m_i is a nonnegative integer. An empty block family represents the zero space and has seed rank zero. The maximum over an empty block family is also assigned the value zero. A vector ψ_i∈ C^d_i⊗ C^m_i is identified with a d_i× m_i coefficient matrix C_i.

    Exact mathematical passage
    
    \cA
    \cong
    \bigoplus_{i=1}^r
    \left(M_{d_i}(\bbC)\otimes I_{m_i}\right)
    
\cA_\ellUse in source · 1 passage

Search aliases: cA_ℓ A_ℓ cA ell mathcal ell

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  • Use in source · Read passage · 01_finite_core.tex, line 1003

    At resolution ℓ, define Q_ℓ = ( A_ℓ, H_ℓ, D_ℓ, {P_ℓ,α}, E_ℓ, C_ℓ, Π_ℓ^phys, T_ℓ ). In order, the entries specify the observable algebra, Hilbert space, geometric or Dirac-type operator, packet projectors, embedding into the fine space, reconstruction onto the coarse space, physical constraint projector, and transfer operator. The maps have types E_ℓ: H_ℓ→ H_ℓ+1 and C_ℓ: H_ℓ+1→ H_ℓ. The left inverse relation C_ℓ E_ℓ=I alone does not imply C_ℓ=E_ℓ^* or make the embedding isometric.

    Exact mathematical passage
    
    \boxed{
    \mathfrak Q_\ell
    =
    \left(
    \cA_\ell,
    \cH_\ell,
    D_\ell,
    \{P_{\ell,\alpha}\},
    E_\ell,
    C_\ell,
    \Pi_\ell^{\mathrm{phys}},
    T_\ell
    \right).
    }
    
\cCUse in source · 3 passages

Search aliases: cC C mathcal

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  • Use in source · Read passage · 01_finite_core.tex, line 792

    Let P=P^*=P^2 project onto a code space C⊂ H, and let E_1,…,E_r be a finite family of complex error matrices. Neither a nonzero code nor channel normalization is assumed unless stated. The operators P E_a^*E_bP are the obstruction packets on the code. If they retain information about the logical state beyond one scalar multiple of P, the environment can distinguish logical states and exact correction is impossible.

    Exact mathematical passage
    \cC\subset\cH
\CC^3Use in source · 9 passages

Search aliases: CC^3 C^3 CC mathbb

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  • Use in source · monograph_atlas.tex, line 74

    vpage5Why one seed is not always enoughAN EXACT MULTIPLICITY LOWER BOUNDTraditional edition: Theorem II.2.3. Consider M_2( C)⊗ I_3 acting on C^2⊗ C^3. A seed is a 2×3 coefficient matrix. Its two rows span at most two directions in the three-dimensional multiplicity factor. Therefore no single seed is cyclic for this algebra. C_1=mat1 · 0 · 0

    Exact mathematical passage
    \CC^2\otimes\CC^3
\CC^4Use in source · 1 passage

Search aliases: CC^4 C^4 CC mathbb

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  • Use in source · monograph_atlas.tex, line 753

    l is Cket0, and the full algebra closes: [C_x,C_y]=2 i C_z, [C_y,C_z]=2 i C_x, [C_z,C_x]=2 i C_y. These are uncompressed identities. They supply an actual closure test in the quotient by the constraint span, unlike the automatic compressed zero on the physical kernel. xfigconstraint_image headExact transport holds on the coarse image Embed by the coordinate isometry R: C^3→ C^4 and set widetilde C_a=C_a⊕1. Then widetilde C_aR=RC_a, so [widetilde C_a,widetilde C_b]R=R[C_a,C_b]. The coarse physica…

    Exact mathematical passage
    R:\CC^3\to\CC^4
\CC^6Use in source · 1 passage

Search aliases: CC^6 C^6 CC mathbb

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  • Use in source · monograph_atlas.tex, line 86

    o groups of size at most d attains this bound. For a direct sum of such blocks, the worst block determines the required count: srank_AA(HH)=max_ilceil m_i/d_irceil. This is an invariant of the declared representation of the algebra, and depends on more than the dimension of the Hilbert space alone. If the available algebra were enlarged to the full matrix algebra on C^6, every nonzero seed would instead be cyclic.

    Exact mathematical passage
    \CC^6
\CC^8Use in source · 1 passage

Search aliases: CC^8 C^8 CC mathbb

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  • Use in source · monograph_atlas.tex, line 52

    2,a_3), put W_a=X_1^a_1X_2^a_2X_3^a_3. W_aψ_0=keta_1a_2a_3. The drawing shows the actual eight states reached by these words. Dashed edges connect the two squares by changing the first bit. The other edges change one of the remaining bits. vfigaddresses headTwo different meanings of ``reach'' The eight vectors are orthonormal, so their linear span is all of C^8. This proves cyclicity for the algebra generated by the flips. Preparing every normalized vector requires more than products of these fl…

    Exact mathematical passage
    \CC^8
\CC^dUse in source · 1 passage

Search aliases: CC^d C^d CC mathbb

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  • Use in source · Read passage · 02_strengthened.tex, line 120

    [Orbit dimension of one seed] For integers d≥1, m≥0, and the action of M_d( C)⊗ I_m on C^d⊗ C^m, let C_ψ be the coefficient matrix of ψ. Then dimspan{(A⊗ I_m)ψ:A∈ M_d( C)} = drank C_ψ. The vector is cyclic exactly when rank C_ψ=m.

    Exact mathematical passage
    \CC^d\otimes\CC^m
\CC^{d_r}Use in source · 1 passage

Search aliases: CC^d_r C^d_r CC mathbb

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  • Use in source · Read passage · 02_strengthened.tex, line 111

    Let A ≅ ⊕_r=1^s (M_d_r( C)⊗ I_m_r) act on H ≅ ⊕_r=1^s ( C^d_r⊗ C^m_r). Assume d_r,m_r≥1 for each displayed block. For an empty block family, the seed rank and the displayed finite supremum are defined as zero. A vector in one block is identified with a d_r by m_r coefficient matrix.

    Exact mathematical passage
    
    \Hcal
    \cong
    \bigoplus_{r=1}^{s}
    \bigl(\CC^{d_r}\otimes\CC^{m_r}\bigr).
    
\CC^mUse in source · 2 passages

Search aliases: CC^m C^m CC mathbb

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  • Use in source · Read passage · 02_strengthened.tex, line 120

    [Orbit dimension of one seed] For integers d≥1, m≥0, and the action of M_d( C)⊗ I_m on C^d⊗ C^m, let C_ψ be the coefficient matrix of ψ. Then dimspan{(A⊗ I_m)ψ:A∈ M_d( C)} = drank C_ψ. The vector is cyclic exactly when rank C_ψ=m.

    Exact mathematical passage
    \CC^d\otimes\CC^m
\CC^{m_r}Use in source · 2 passages

Search aliases: CC^m_r C^m_r CC mathbb

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  • Use in source · Read passage · 02_strengthened.tex, line 111

    Let A ≅ ⊕_r=1^s (M_d_r( C)⊗ I_m_r) act on H ≅ ⊕_r=1^s ( C^d_r⊗ C^m_r). Assume d_r,m_r≥1 for each displayed block. For an empty block family, the seed rank and the displayed finite supremum are defined as zero. A vector in one block is identified with a d_r by m_r coefficient matrix.

    Exact mathematical passage
    
    \Hcal
    \cong
    \bigoplus_{r=1}^{s}
    \bigl(\CC^{d_r}\otimes\CC^{m_r}\bigr).
    
\CC^nUse in source · 2 passages

Search aliases: CC^n C^n CC mathbb

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  • Use in source · monograph_atlas.tex, line 765

    vpage39Two routes to a bounded Hamiltonian limitEXACT EMBEDDINGS AND A SUMMABLE TAILTraditional edition: Theorem II.13.2, Theorem II.13.4, Corollary II.13.5. For the exact route, let HH_n= C^n with coordinate inclusions and H_n=diag(0,1,1/2,…,1/(n-1)), H_1=(0). The old energies are retained at every level, H_n+1R_n=R_nH_n, and normH_n≤1. On the Hilbert space of the direct limit ℓ^2( N_0), the diagonal sequence defines a bounded self-adjoint H_∞. Projectors onto even addresses also intertwine and…

    Exact mathematical passage
    \HH_n=\CC^n
\CC^{n+1}Use in source · 1 passage

Search aliases: CC^n+1 C^n+1 CC mathbb

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  • Use in source · tower_tail.tex, line 5

    H_n=diag(0,1,1/2,…); node[draw,fill=black!7,align=center] (b) at (9.5,2.2) C^n+1

    Exact mathematical passage
    \CC^{n+1}
\CC^rUse in source · 2 passages

Search aliases: CC^r C^r CC mathbb

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  • Use in source · Read passage · 02_strengthened.tex, line 851

    Let P(x) be a smooth rank r orthogonal projector over a parameter manifold. Choose a local isometry V(x): C^r⟶ H, V(x)V(x)^*=P(x).

    Exact mathematical passage
    
    V(x):\CC^r\longrightarrow\Hcal,
    \qquad
    V(x)V(x)^*=P(x).
    
\cDUse in source · 2 passages

Search aliases: cD D mathcal

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  • Use in source · Read passage · 01_finite_core.tex, line 691

    [Block-diagonal measurement invariance] Let {P_α} be a complete packet family, and suppose every measurement effect is packet diagonal: E_k=∑_α P_α E_kP_α. Define the packet-dephased state D_P(ρ)=∑_α P_αρ P_α. Then Tr(E_kρ) = Tr(E_k D_P(ρ)) for every outcome k.

    Exact mathematical passage
    
    \cD_P(\rho)=\sum_\alpha P_\alpha\rho P_\alpha.
    
\cD_PUse in source · 2 passages

Search aliases: cD_P D_P cD mathcal

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  • Use in source · Read passage · 01_finite_core.tex, line 691

    [Block-diagonal measurement invariance] Let {P_α} be a complete packet family, and suppose every measurement effect is packet diagonal: E_k=∑_α P_α E_kP_α. Define the packet-dephased state D_P(ρ)=∑_α P_αρ P_α. Then Tr(E_kρ) = Tr(E_k D_P(ρ)) for every outcome k.

    Exact mathematical passage
    
    \cD_P(\rho)=\sum_\alpha P_\alpha\rho P_\alpha.
    
\cFUse in source · 2 passages

Search aliases: cF F mathcal

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  • Use in source · Read passage · 01_finite_core.tex, line 632

    For an orthogonal rank-one complex projector, use the scalar connection convention A=-i⟨ u,du⟩ in a local unit frame. The associated scalar curvature density is F_μν =-iTr(P[∂_μ P,∂_ν P]). On the Bloch sphere, P(θ,ϕ) = frac12(I+ n(θ,ϕ)·σ), where n=(sinθcosϕ,sinθsinϕ,cosθ). The Pauli multiplication law gives [∂_θ P,∂_ϕ P] =fraci2(∂_θ nmathbin×∂_ϕ n)·σ. Using Tr(P a·σ)= n· a therefore yields F_θϕ =frac12 n·(∂_θ nmathbin×∂_ϕ n) =frac12sinθ. The scalar sign changes if the opposite convention for A i…

    Exact mathematical passage
    
    \cF_{\mu\nu}
    =-i\Tr\left(P[\partial_\mu P,\partial_\nu P]\right).
    
\cF_{\theta\phi}Use in source · 1 passage

Search aliases: cF_θϕ F_θϕ cF theta phi mathcal theta phi

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  • Use in source · Read passage · 01_finite_core.tex, line 652

    I+ n(θ,ϕ)·σ), where n=(sinθcosϕ,sinθsinϕ,cosθ). The Pauli multiplication law gives [∂_θ P,∂_ϕ P] =fraci2(∂_θ nmathbin×∂_ϕ n)·σ. Using Tr(P a·σ)= n· a therefore yields F_θϕ =frac12 n·(∂_θ nmathbin×∂_ϕ n) =frac12sinθ. The scalar sign changes if the opposite convention for A is chosen. This explicit calculation is not a separate entry among the 19 items in the Lean register.

    Exact mathematical passage
    
    \boxed{\cF_{\theta\phi}
    =\frac12\mathbf n\cdot(\partial_\theta\mathbf n\mathbin{\times}\partial_\phi\mathbf n)
    =\frac12\sin\theta.}
    
\cF_{\mu\nu}Use in source · 1 passage

Search aliases: cF_μν F_μν cF mu nu mathcal mu nu

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  • Use in source · Read passage · 01_finite_core.tex, line 632

    For an orthogonal rank-one complex projector, use the scalar connection convention A=-i⟨ u,du⟩ in a local unit frame. The associated scalar curvature density is F_μν =-iTr(P[∂_μ P,∂_ν P]). On the Bloch sphere, P(θ,ϕ) = frac12(I+ n(θ,ϕ)·σ), where n=(sinθcosϕ,sinθsinϕ,cosθ). The Pauli multiplication law gives [∂_θ P,∂_ϕ P] =fraci2(∂_θ nmathbin×∂_ϕ n)·σ. Using Tr(P a·σ)= n· a therefore yields F_θϕ =frac12 n·(∂_θ nmathbin×∂_ϕ n) =frac12sinθ. The scalar sign changes if the opposite convention for A i…

    Exact mathematical passage
    
    \cF_{\mu\nu}
    =-i\Tr\left(P[\partial_\mu P,\partial_\nu P]\right).
    
\cH_AUse in source · 2 passages

Search aliases: cH_A H_A cH mathcal

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  • Use in source · Read passage · 01_finite_core.tex, line 137

    [Local orbit and Schmidt rank] Let ψ∈ H_A⊗ H_B, with dim H_A=d_A≥1, and let r be its Schmidt rank. The reduced positive operator on B is ρ_B=Tr_A(ketψbraψ). Normalization of ψ does not affect its support. Then dimspan{(A⊗ I_B)ψ:A∈ M_d_A( C)} =d_A r. In particular, local operators on A generate the complete bipartite Hilbert space exactly when the reduced state on B has full support.

    Exact mathematical passage
    \psi\in\cH_A\otimes\cH_B
\cH_BUse in source · 2 passages

Search aliases: cH_B H_B cH mathcal

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  • Use in source · Read passage · 01_finite_core.tex, line 137

    [Local orbit and Schmidt rank] Let ψ∈ H_A⊗ H_B, with dim H_A=d_A≥1, and let r be its Schmidt rank. The reduced positive operator on B is ρ_B=Tr_A(ketψbraψ). Normalization of ψ does not affect its support. Then dimspan{(A⊗ I_B)ψ:A∈ M_d_A( C)} =d_A r. In particular, local operators on A generate the complete bipartite Hilbert space exactly when the reduced state on B has full support.

    Exact mathematical passage
    \psi\in\cH_A\otimes\cH_B
\cH_\ellUse in source · 3 passages

Search aliases: cH_ℓ H_ℓ cH ell mathcal ell

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  • Use in source · Read passage · 01_finite_core.tex, line 1003

    At resolution ℓ, define Q_ℓ = ( A_ℓ, H_ℓ, D_ℓ, {P_ℓ,α}, E_ℓ, C_ℓ, Π_ℓ^phys, T_ℓ ). In order, the entries specify the observable algebra, Hilbert space, geometric or Dirac-type operator, packet projectors, embedding into the fine space, reconstruction onto the coarse space, physical constraint projector, and transfer operator. The maps have types E_ℓ: H_ℓ→ H_ℓ+1 and C_ℓ: H_ℓ+1→ H_ℓ. The left inverse relation C_ℓ E_ℓ=I alone does not imply C_ℓ=E_ℓ^* or make the embedding isometric.

    Exact mathematical passage
    
    \boxed{
    \mathfrak Q_\ell
    =
    \left(
    \cA_\ell,
    \cH_\ell,
    D_\ell,
    \{P_{\ell,\alpha}\},
    E_\ell,
    C_\ell,
    \Pi_\ell^{\mathrm{phys}},
    T_\ell
    \right).
    }
    
\cH_{\ell+1}Use in source · 2 passages

Search aliases: cH_ℓ+1 H_ℓ+1 cH ell mathcal ell

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  • Use in source · Read passage · 01_finite_core.tex, line 1019

    hfrak Q_ℓ = ( A_ℓ, H_ℓ, D_ℓ, {P_ℓ,α}, E_ℓ, C_ℓ, Π_ℓ^phys, T_ℓ ). In order, the entries specify the observable algebra, Hilbert space, geometric or Dirac-type operator, packet projectors, embedding into the fine space, reconstruction onto the coarse space, physical constraint projector, and transfer operator. The maps have types E_ℓ: H_ℓ→ H_ℓ+1 and C_ℓ: H_ℓ+1→ H_ℓ. The left inverse relation C_ℓ E_ℓ=I alone does not imply C_ℓ=E_ℓ^* or make the embedding isometric.

    Exact mathematical passage
    E_\ell:\cH_\ell\to\cH_{\ell+1}
\mathrm{CNOT}Use in source · 1 passage

Search aliases: CNOT mathrm

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  • Use in source · monograph_atlas.tex, line 136

    le vector occupies both parity packets. The final vector occupies only the even packet. vfigbell_circuit headHow the exact path expansion works Insert P_rm even+P_rm odd=I between the two gates. Each summand records a particular intermediate packet, while the boundary projectors select its input and output packets. Summing all terms recovers the original 4×4 circuit matrix: ∑_a,b,cP_b CNOT P_a (H_rm Had⊗ I)P_c =CNOT(H_rm Had⊗ I). This expansion is an identity even though the intermediate parity …

    Exact mathematical passage
    
    \sum_{a,b,c}P_b\,\mathrm{CNOT}\,P_a
    (H_{\rm Had}\otimes I)P_c
    =\mathrm{CNOT}(H_{\rm Had}\otimes I).
    
\mathrm{coarse}Use in source · 2 passages

Search aliases: coarse mathrm

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  • Use in source · Read passage · 01_finite_core.tex, line 247

    [Tensor/polyphase refinement] For each residue r∈ Z/N Z, define P_r^coarse = ∑_j_1+⋯+j_m≡ rpmod N P^(1)_j_1⊗⋯⊗ P^(m)_j_m. Then the P_r^coarse are complete orthogonal projectors, and every coarse packet is the exact sum of its fine descendants.

    Exact mathematical passage
    
    \boxed{
    P_r^{\mathrm{coarse}}
    =
    \sum_{j_1+\cdots+j_m\equiv r\pmod N}
    P^{(1)}_{j_1}\otimes\cdots\otimes P^{(m)}_{j_m}.
    }
    
\operatorname{coeff}Use in source · 1 passage

Search aliases: coeff operatorname

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  • Use in source · Read passage · 03_supplement_03.tex, line 46

    Schmidt rank and the reduced state. Use coordinates ψ_ij in the standard product basis and let C_ij=ψ_ij. An explicit linear equivalence identifies the state vector on the product index set with its coefficient matrix. The implementation checks the actual Kronecker action: coeff((A⊗ I_B)ψ)=AC. It also proves that the transported matrix orbit equals the span of the state vectors obtained by this Kronecker action. The dimension formula therefore applies to the physical local action on the state sp…

    Exact mathematical passage
    
    \operatorname{coeff}\bigl((A\otimes I_B)\psi\bigr)=AC.
    
\commUse in source · 2 passages

Search aliases: comm

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  • Use in source · Read passage · 03_supplement_02.tex, line 146

    Define C=∑_aD_aP_a(t). Then C=frac12∑_acommD_aP_a(t), C^*=-C, and, for every b, commCP_b(t)=D_b.

    Exact mathematical passage
    
     \boxed{\quad C=\frac12\sum_a\comm{D_a}{P_a(t)},\qquad C^*=-C,\quad}
    
\cosUse in source · 10 passages

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  • Use in source · monograph_atlas.tex, line 188

    vpage11Quantify the amplitude that escapesCOMMUTATORS AND PROBABILITY BOUNDSTraditional edition: Theorem II.5.3, Corollary II.5.4. For a two-level system, choose H=ε X, P=ket0bra0, and Q=I-P. Direct exponentiation gives e^- i tH=cos(ε t)I- isin(ε t)X, normQe^- i tHP=|sin(ε t)|, norm[H,P]=|ε|. The general commutator estimate becomes the elementary bound |sin u|≤ |u|. Unitarity also bounds the amplitude by one. vfigleakage headFrom a norm to a probability For this initial state, the escape probabi…

    Exact mathematical passage
    
    e^{-\ii tH}=\cos(\varepsilon t)I-\ii\sin(\varepsilon t)X,
    \quad
    \norm{Qe^{-\ii tH}P}=|\sin(\varepsilon t)|,
    \quad\norm{[H,P]}=|\varepsilon|.
    
\cos^2Use in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 261

    E_x={v:P(x)v=v}. To compare it with a nearby anchor fiber E_a, the completion proof constructs T_a(x)=P(x)P(a)+(I-P(x))(I-P(a)). It equals the identity at the anchor and intertwines the two projectors. Where it is invertible, its restriction provides local fiber coordinates. vfigrange_atlas headAn exact example of the domain restriction For the rotating line and anchor P(0), T_0(t)=cos t U(t), det T_0(t)=cos^2t. The chart fails at t=π/2, but P(π/2)=diag(0,1) is a perfectly regular rank-one proje…

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    T_0(t)=\cos t\,U(t),\qquad \det T_0(t)=\cos^2t.
    
D^*Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 1786

    [Stability of the self energy] Let D=D^* and widetilde D=widetilde D^* act on one fixed hidden Hilbert space, and let B,widetilde B map that hidden space to one fixed retained Hilbert space. Define Σ(z)=B(z-D)^-1B^*, widetildeΣ(z)=widetilde B(z-widetilde D)^-1widetilde B^*. Assume norm B,normwidetilde B≤ g and dist(z,Spec D), dist(z,Specwidetilde D) ≥δ>0. Then normΣ(z)-widetildeΣ(z) ≤ frac2gδnormB-widetilde B + fracg^2δ^2normD-widetilde D.

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    D=D^*
D^{-1}Use in source · 4 passages

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  • Use in source · monograph_atlas.tex, line 669

    Sigma|=|1-frac8156|=frac2556, frac2gδ|B-widetilde B| +fracg^2δ^2|D-widetilde D|=frac2132. The theorem bounds the difference using a common spectral gap. Applying the bound uniformly to a refinement family requires uniform spectral separation and control of the couplings. headA series near zero energy and its exact remainder At z=1/2, |z| |D^-1|=1/4<1, so Σ(z)=-∑_n=0^∞fracz^n2^n+1. After the first four terms, the exact remainder has magnitude 1/384. The geometric series controls the infinite tail…

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    |z|\,|D^{-1}|=1/4<1
D^{-n-1}Use in source · 2 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 1633

    [Low energy expansion] Assume D is invertible and abs znormD^-1<1. Then Σ(z) =- ∑_n=0^∞ z^nBD^-n-1B^* with norm convergence. In particular, F_P(z) = z-A+BD^-1B^*+O(abs znorm B^2normD^-1^2).

    Exact mathematical passage
    
    \Sigma(z)
    =-
    \sum_{n=0}^{\infty}
    z^nBD^{-n-1}B^*
    
D^2Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 1953

    A finite spectral datum consists of a finite dimensional Hilbert space, a nonnegative self adjoint operator L, and any declared packet family. One may take L=D^2 for a finite Dirac type operator or a graph Laplacian. Related geometric viewpoints appear in [source reference].

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    L=D^2
d^4Use in source · 1 passage

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  • Use in source · Read passage · 01_finite_core.tex, line 1240

    [Einstein infrared limit] There exist semiclassical packet states Ψ_g,ℓ such that the effective action converges to frac116π G ∫sqrt-g (R-2Λ) d^4x with controlled higher-order corrections.

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    \frac1{16\pi G}
    \int\sqrt{-g}\,(R-2\Lambda)\,d^4x
    
D_aUse in source · 7 passages

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  • Use in source · Read passage · 03_supplement_02.tex, line 138

    Let P_a(s) be a finite family in a normed real algebra with a continuous compatible adjoint. Assume actual derivatives D_a=dot P_a(t) exist and, for all parameter values under consideration, P_aP_b=δ_abP_a, ∑_aP_a=I, P_a^*=P_a. In the supplied Lean theorem, the curves are defined on R and the projector laws hold at every real parameter. The algebraic formulation applies to matrices and bounded operators whenever they satisfy the stated typeclass hypotheses.

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    D_a=\dot P_a(t)
d_AUse in source · 8 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 137

    [Local orbit and Schmidt rank] Let ψ∈ H_A⊗ H_B, with dim H_A=d_A≥1, and let r be its Schmidt rank. The reduced positive operator on B is ρ_B=Tr_A(ketψbraψ). Normalization of ψ does not affect its support. Then dimspan{(A⊗ I_B)ψ:A∈ M_d_A( C)} =d_A r. In particular, local operators on A generate the complete bipartite Hilbert space exactly when the reduced state on B has full support.

    Exact mathematical passage
    \dim\cH_A=d_A\ge1
D_a^*Use in source · 1 passage

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  • Use in source · Read passage · 03_supplement_02.tex, line 161

    The derivative product rule and uniqueness of derivatives give D_aP_b+P_aD_b=δ_abD_a. Differentiating completeness and adjoint invariance gives ∑_aD_a=0, D_a^*=D_a. These are proved derivative consequences, not additional axioms supplied in place of differentiation.

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     \sum_aD_a=0,\qquad D_a^*=D_a.
    
D_bUse in source · 5 passages

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  • Use in source · Read passage · 03_supplement_02.tex, line 150

    Define C=∑_aD_aP_a(t). Then C=frac12∑_acommD_aP_a(t), C^*=-C, and, for every b, commCP_b(t)=D_b.

    Exact mathematical passage
    
     \boxed{\comm{C}{P_b(t)}=D_b.}
    
D_iUse in source · 1 passage

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  • Use in source · Read passage · 03_supplement_02.tex, line 47

    Let F be an arbitrary finite set of factors and let D_i be a finite coordinate index for factor i. For matrix families A_i, define the coordinate tensor product on the product index space by T(A)(x,y)=∏_i∈ F A_i(x_i,y_i). The proof first establishes the laws for multiplication, identity, adjoints, and finite sums. These laws apply to any finite number of factors with the stated finite coordinate sets.

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    D_i
d_{ja}Use in source · 1 passage

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  • Use in source · Read passage · 01_finite_core.tex, line 829

    ry vector orthogonal to ψ, the quadratic form on the left is a sum of nonnegative squared absolute values and equals zero. Each L_jψ therefore lies in the span of ψ. A linear operator that preserves every line in C is scalar there: apply it to two independent vectors and their sum. The one-dimensional case is immediate, and the claim is vacuous for the zero code. Consequently K_jE_aP=d_jaP. Recovery completeness now gives PE_a^*E_bP · =∑_j (K_jE_aP)^*(K_jE_bP)

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    K_jE_aP=d_{ja}P.
    
d_{jb}Use in source · 1 passage

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  • Use in source · Read passage · 01_finite_core.tex, line 833

    he left is a sum of nonnegative squared absolute values and equals zero. Each L_jψ therefore lies in the span of ψ. A linear operator that preserves every line in C is scalar there: apply it to two independent vectors and their sum. The one-dimensional case is immediate, and the claim is vacuous for the zero code. Consequently K_jE_aP=d_jaP. Recovery completeness now gives PE_a^*E_bP · =∑_j (K_jE_aP)^*(K_jE_bP) · =(∑_joverlined_jad_jb)P. The coefficients form a Gram matrix, hence are positive se…

    Exact mathematical passage
    
    \begin{aligned}
    PE_a^*E_bP
    &=\sum_j (K_jE_aP)^*(K_jE_bP)\\
    &=\left(\sum_j\overline{d_{ja}}d_{jb}\right)P.
    \end{aligned}
    
d_{L,a}Use in source · 2 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 1999

    [Heat packet decomposition] If [L,P_a]=0 for every packet, then Z_L(t)=∑_aZ_L,a(t), Z_L,a(t)=Tr(P_a e^-tL). The global spectral dimension is the average of the packet dimensions weighted by their heat traces: d_L(t) = ∑_a:Z_L,a(t)>0 fracZ_L,a(t)Z_L(t) d_L,a(t), where d_L,a(t) =2t fracTr(P_aL e^-tL)Z_L,a(t) for nonempty packet heat traces.

    Exact mathematical passage
    
    d_L(t)
    =
    \sum_{a:Z_{L,a}(t)>0}
    \frac{Z_{L,a}(t)}{Z_L(t)}
     d_{L,a}(t),
    
d_{L_N}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 2153

    [Rigorous intermediate dimension window] For every ε>0, there is a diffusion time t_ε>0 and an integer N_ε such that absd_L_N(t_ε)-d<ε for every N≥ N_ε.

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    \abs{d_{L_N}(t_\varepsilon)-d}<\varepsilon
    
d_NUse in source · 4 passages

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  • Use in source · monograph_atlas.tex, line 725

    vpage37The dimension window has an order of limitsFINITE HEAT DATA AND THE QUANTIFIERSTraditional edition: Theorem II.11.5, Corollary II.11.8. For the unit circle grid with N sites, the scaled eigenvalues are λ_N(k)=4N^2sin^2(π k/N). Put Z_N(t)=∑_ke^-tλ_N(k) and d_N(t)=2t∑_kλ_N(k)e^-tλ_N(k)/Z_N(t).

    Exact mathematical passage
    d_N(t)=2t\sum_k\lambda_N(k)e^{-t\lambda_N(k)}/Z_N(t)
d_rUse in source · 9 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 104

    Let A ≅ ⊕_r=1^s (M_d_r( C)⊗ I_m_r) act on H ≅ ⊕_r=1^s ( C^d_r⊗ C^m_r). Assume d_r,m_r≥1 for each displayed block. For an empty block family, the seed rank and the displayed finite supremum are defined as zero. A vector in one block is identified with a d_r by m_r coefficient matrix.

    Exact mathematical passage
    
    \Acal
    \cong
    \bigoplus_{r=1}^{s}
    \bigl(M_{d_r}(\CC)\otimes I_{m_r}\bigr)
    
D_{\rm computational}Use in source · 2 passages

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  • Use in source · monograph_atlas.tex, line 299

    g Every effect in the computational basis E_a=ket abra a has the same expectation on both matrices, namely 1/2 at 00 and 11 and zero elsewhere. These measurements read only the diagonal. They cannot distinguish the pure Bell state from this incoherent mixture. headA measurement that resolves the difference Use the valid two-outcome measurement with effects E=ρ and I-E. Then Tr(Eρ)=1, Tr (E D_rm computational(ρ))=frac12. The effect itself is not diagonal in the fine computational packets. It comp…

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    \Tr(E\rho)=1,\qquad
    \Tr\!\left(E D_{\rm computational}(\rho)\right)=\frac12.
    
D_{\rm parity}Use in source · 1 passage

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  • Use in source · dephasing.tex, line 3

    [x=1cm,y=1cm,>=Stealth,line cap=round,line join=round] path[use as bounding box] (0,-.6) rectangle (14,4.8); node[font=small,align=center,font=small] at (2.25,4.65) 2ρ, also 2D_rm parity(ρ); path[draw=black!30,fill=black!8] (0.75,3.2) rectangle (1.5,3.95); node[font=small,align=center,font=small] at (1.125,3.575) 1; path[draw=black!30,fill=white] (1.5,3.2) rectangle (2.25,3.95); node[font=small,align=center,font=small] at (1.875,3.575) 0; path[draw=black!30,fill=white] (2.25,3.2) rectangle (3,3.…

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    2D_{\rm parity}(\rho)
d_{\rm torus}Use in source · 3 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 2120

    [Continuum torus small time dimension] Let d_rm torus(t) =-2frac dlog Z_d(t) dlog t. Then d_rm torus(t) = d+O(t^-1 e^-1/(4t)) as tdownarrow0.

    Exact mathematical passage
    
    d_{\rm torus}(t)
    =-2\frac{\dd\log Z_d(t)}{\dd\log t}.
    
d_sUse in source · 6 passages

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  • Use in source · monograph_atlas.tex, line 442

    vpage24A dimension curve is a scale diagnosticTHE EXACT HEAT TRACE ON FOUR SITESTraditional edition: Definition II.11.1, Proposition II.11.2. For the Laplacian on a cycle with four sites L=2I-S-S^*, the eigenvalues are 0,2,2,4. The normalized heat trace and its diagnostic of spectral dimension are therefore K(τ)=frac1+2e^-2τ+e^-4τ4 =frac(1+e^-2τ)^24, d_s(τ)=-2τfracK'(τ)K(τ) =frac8τe^2τ+1. No numerical differentiation is needed for this finite example. vfigspectral_dimension headBoth ends reflect…

    Exact mathematical passage
    
    K(\tau)=\frac{1+2e^{-2\tau}+e^{-4\tau}}4
    =\frac{(1+e^{-2\tau})^2}4,
    \qquad
     d_s(\tau)=-2\tau\frac{K'(\tau)}{K(\tau)}
    =\frac{8\tau}{e^{2\tau}+1}.
    
d_{s,2}Use in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 454

    For the Cartesian product of two identical cycles with four sites, the Laplacian eigenvalues add and the heat traces multiply: K_2=K^2. Consequently d_s,2=2d_s exactly. The product identity determines the second curve exactly from the first.

    Exact mathematical passage
    d_{s,2}=2d_s
d_s^{(1)}Use in source · 1 passage

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  • Use in source · Read passage · 01_finite_core.tex, line 1188

    [Spectral dimension] The median intermediate plateaus were d_s^(1)=1.00062, d_s^(2)=2.03781. These tests recover the expected dimensions of the chosen finite geometries. They do not select a physical theory of quantum spacetime.

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    d_s^{(1)}=1.00062,
    \qquad
    d_s^{(2)}=2.03781.
    
d_s^{(2)}Use in source · 1 passage

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  • Use in source · Read passage · 01_finite_core.tex, line 1188

    [Spectral dimension] The median intermediate plateaus were d_s^(1)=1.00062, d_s^(2)=2.03781. These tests recover the expected dimensions of the chosen finite geometries. They do not select a physical theory of quantum spacetime.

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    d_s^{(1)}=1.00062,
    \qquad
    d_s^{(2)}=2.03781.
    
D_zUse in source · 5 passages

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  • Use in source · Read passage · 03_supplement_01.tex, line 106

    -C · zI_Q-D. Set D_z=zI_Q-D, S_z=zI_P-A-BD_z^-1C. The effective Hamiltonian is H_eff(z)=A+BD_z^-1C, so S_z=zI_P-H_eff(z).

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    D_z=zI_Q-D,\qquad S_z=zI_P-A-BD_z^{-1}C.
    
D_z^{-1}Use in source · 2 passages

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  • Use in source · Read passage · 03_supplement_01.tex, line 106

    -C · zI_Q-D. Set D_z=zI_Q-D, S_z=zI_P-A-BD_z^-1C. The effective Hamiltonian is H_eff(z)=A+BD_z^-1C, so S_z=zI_P-H_eff(z).

    Exact mathematical passage
    
    D_z=zI_Q-D,\qquad S_z=zI_P-A-BD_z^{-1}C.
    
D_\ellUse in source · 2 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 1003

    At resolution ℓ, define Q_ℓ = ( A_ℓ, H_ℓ, D_ℓ, {P_ℓ,α}, E_ℓ, C_ℓ, Π_ℓ^phys, T_ℓ ). In order, the entries specify the observable algebra, Hilbert space, geometric or Dirac-type operator, packet projectors, embedding into the fine space, reconstruction onto the coarse space, physical constraint projector, and transfer operator. The maps have types E_ℓ: H_ℓ→ H_ℓ+1 and C_ℓ: H_ℓ+1→ H_ℓ. The left inverse relation C_ℓ E_ℓ=I alone does not imply C_ℓ=E_ℓ^* or make the embedding isometric.

    Exact mathematical passage
    
    \boxed{
    \mathfrak Q_\ell
    =
    \left(
    \cA_\ell,
    \cH_\ell,
    D_\ell,
    \{P_{\ell,\alpha}\},
    E_\ell,
    C_\ell,
    \Pi_\ell^{\mathrm{phys}},
    T_\ell
    \right).
    }
    
D_{\ell+1}Use in source · 1 passage

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  • Use in source · Read passage · 01_finite_core.tex, line 1038

    A coherent refinement should satisfy C_ℓ E_ℓ=I and P_ℓ,α = C_ℓ ( ∑_βsuccαP_ℓ+1,β ) E_ℓ. For an operator D, define the refinement defect Δ_ℓ(D) =C_ℓ D_ℓ+1E_ℓ-D_ℓ. Exact resolution independence is Δ_ℓ(D)=0. When exact equality is too strong, the correct continuum problem is to prove convergence of the resolvents and uniform control of the effective self-energies.

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    \Delta_\ell(D)
    =C_\ell D_{\ell+1}E_\ell-D_\ell.
    
\ddot xUse in source · 4 passages

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  • Use in source · monograph_atlas.tex, line 409

    returns periodically. Deleting the hidden row and column would instead leave the zero Hamiltonian and predict x(t)=1. vfigmemory headEliminate exactly, not approximately Integrating the second equation with y(0)=0 gives y(t)=- i∫_0^tx(s) ds. Substitution produces dot x(t)=-∫_0^tx(s) ds. The memory kernel is the constant function one. Differentiating once more recovers ddot x=-x with x(0)=1 and dot x(0)=0, explaining the cosine solution. A nonzero hidden initial state would add a forcing term tha…

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    \ddot x=-x
\dephUse in source · 4 passages

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  • Use in source · Read passage · 03_supplement_01.tex, line 75

    Measurements: source Theorem 7.1. For finite complex matrices, define packet dephasing by D_P(X)=∑_aP_aXP_a. The code proves idempotence and trace duality: D_P( D_P(X))= D_P(X), tr( D_P(E)ρ)=tr(E D_P(ρ)). Trace duality follows term by term from cyclicity: tr(P_aEP_aρ)=tr(EP_aρ P_a). Therefore an effect that is diagonal in the packets, D_P(E)=E, satisfies tr(Eρ)=tr(E D_P(ρ)). The proof holds for arbitrary finite complex matrices E and ρ. Density matrices and positive measurement effects are valid…

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    \deph(X)=\sum_aP_aXP_a.
    
\detUse in source · 7 passages

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  • Use in source · monograph_atlas.tex, line 261

    E_x={v:P(x)v=v}. To compare it with a nearby anchor fiber E_a, the completion proof constructs T_a(x)=P(x)P(a)+(I-P(x))(I-P(a)). It equals the identity at the anchor and intertwines the two projectors. Where it is invertible, its restriction provides local fiber coordinates. vfigrange_atlas headAn exact example of the domain restriction For the rotating line and anchor P(0), T_0(t)=cos t U(t), det T_0(t)=cos^2t. The chart fails at t=π/2, but P(π/2)=diag(0,1) is a perfectly regular rank-one proje…

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    T_0(t)=\cos t\,U(t),\qquad \det T_0(t)=\cos^2t.
    
\operatorname{diag}Use in source · 10 passages

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  • Use in source · Read passage · monograph_examples.tex, line 17

    ordinates to illustrate block inversion. Both the eliminated block and the full operator are invertible, and the plotted values are exact fractions. The example shows why direct compression and resolvent elimination give different results. Normalization changes the map. Let P=|0⟩⟨0| on C^2 and Z=diag(1,-1). The normalized Kraus family sqrt3/4 I, sqrt1/4 Z satisfies ∑_j K_j^*K_j=I and maps P to P. The unnormalized family sqrt3 I, Z satisfies ∑_j E_j^*E_j=4I and maps P to 4P. The two families have…

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    Z=\operatorname{diag}(1,-1)
\dimUse in source · 13 passages

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  • Use in source · monograph_atlas.tex, line 61

    ment changes the local spanSCHMIDT RANK AS ACCESSIBLE MULTIPLICITYTraditional edition: Theorem II.2.2, Corollary II.2.4. Write a bipartite vector as a coefficient matrix C, with the first subsystem indexing rows. Acting only on that subsystem transforms C to AC. Every resulting row remains in the row space of C, and every independent choice of such rows can be obtained in this way. dimSpan{(A⊗ I)ψ:A∈ M_d( C)} =d rank C. vfiglocal_orbits The product vector ket00 has matrix C=diag(1,0). Its local …

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    \dim\Span\{(A\otimes I)\psi:A\in M_d(\CC)\}
    =d\,\rank C.
    
\dim_\CUse in source · 2 passages

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  • Use in source · Read passage · 03_supplement_03.tex, line 9

    A matrix X belongs to O(C) exactly when each of its rows belongs to Row(C). One direction follows by expanding AC. For the converse, choose the coefficients producing each row separately and place them in the corresponding row of A. An explicit linear equivalence therefore gives O(C)≃ Row(C)^d, dim_ C O(C)=d rank C. If d>0, equality with the full d× m coefficient space is equivalent to rank C=m. Consequently a cyclic seed requires m≤ d. The assumption that there is at least one row is essential …

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    \mathcal O(C)\simeq \operatorname{Row}(C)^d,
    \qquad
    \boxed{\dim_\C\mathcal O(C)=d\,\rank C.}
    
\distUse in source · 3 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 1598

    [Uniform self energy bounds] Let δ=dist(z,Spec D)>0, g=norm B. Then normΣ(z)≤fracg^2δ and normΣ'(z)≤fracg^2δ^2. For real E,E' in an interval at distance at least δ from Spec D, normΣ(E)-Σ(E') ≤ fracg^2δ^2absE-E'.

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    \delta=\dist(z,\Spec D)>0,
    \qquad
    g=\norm B.
    
\dot PUse in source · 27 passages

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  • Use in source · monograph_atlas.tex, line 231

    vpage13Differentiate the subspace itselfTHE CANONICAL PACKET CONNECTIONTraditional edition: Theorem II.6.1, Theorem II.6.2. Continue with P(t)=U(t)diag(1,0)U(t)^* and Q(t)=I-P(t). Differentiating P^2=P gives dot P P+Pdot P=dot P, Pdot P P=0. The second identity says that the derivative has no component entirely inside the current packet. It moves the subspace relative to its complement. vfigconnection For this complete pair of packets, define C=dot P P+dot Q Q. Exact calculation yields the const…

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    \dot P P+P\dot P=\dot P,
    \qquad P\dot P P=0.
    
\dot P_aUse in source · 16 passages

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  • Use in source · monograph_atlas.tex, line 244

    n For this complete pair of packets, define C=dot P P+dot Q Q. Exact calculation yields the constant matrix C=J, with C^*=-C and [C,P]=dot P. At t=0, the displayed small matrices allow these identities to be checked by direct multiplication. headFrom two packets to a complete family For differentiable orthogonal projectors P_a summing to the identity, the paper constructs C=∑_adot P_aP_a=frac12∑_a[dot P_a,P_a]. This single connection reproduces the motion of every packet in the family. No basis …

    Exact mathematical passage
    
    C=\sum_a\dot P_aP_a=\frac12\sum_a[\dot P_a,P_a].
    
\dot P_bUse in source · 9 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 532

    [Canonical packet connection] Define C(t) = frac12∑_a[dot P_a(t),P_a(t)] = ∑_adot P_a(t)P_a(t). Then C(t)^*=-C(t) and [C(t),P_b(t)]=dot P_b(t) for every packet b.

    Exact mathematical passage
    
    \boxed{
    [C(t),P_b(t)]=\dot P_b(t)
    }
    
\dot QUse in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 238

    ional edition: Theorem II.6.1, Theorem II.6.2. Continue with P(t)=U(t)diag(1,0)U(t)^* and Q(t)=I-P(t). Differentiating P^2=P gives dot P P+Pdot P=dot P, Pdot P P=0. The second identity says that the derivative has no component entirely inside the current packet. It moves the subspace relative to its complement. vfigconnection For this complete pair of packets, define C=dot P P+dot Q Q. Exact calculation yields the constant matrix C=J, with C^*=-C and [C,P]=dot P. At t=0, the displayed small matr…

    Exact mathematical passage
    
    C=\dot P P+\dot Q Q.
    
\dot U^*Use in source · 2 passages

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  • Use in source · Read passage · 03_supplement_02.tex, line 102

    The explicitly defined coordinate curve y(s)=U(s)^*ψ(s) is differentiable at t, with dot y=dot U^*ψ(t)+U(t)^*dotψ. It satisfies idot y=H_effy(t), H_eff=U(t)^*HU(t)-iU(t)^*dot U. The connection term -iU(t)^*dot U is Hermitian. If H^*=H, then H_eff^*=H_eff.

    Exact mathematical passage
    
     \dot y=\dot U^*\psi(t)+U(t)^*\dot\psi.
    
\dot VUse in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 704

    [Moving frame Hamiltonian] Let U(t) solve idot U(t)=H(t)U(t), U(0)=I, where H(t)=H(t)^* is continuous on the compact time interval under consideration. Set V(t)=W(t)^*U(t). Then idot V(t)=H_rm mov(t)V(t), where H_rm mov(t) = W(t)^*H(t)W(t)- i W(t)^*dot W(t) = W(t)^*(H(t)- i K(t))W(t). The moving frame Hamiltonian is self adjoint.

    Exact mathematical passage
    
    \ii\dot V(t)=H_{\rm mov}(t)V(t),
    
\dot WUse in source · 8 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 27

    The moving packet section treats time dependent projectors. The canonical generator K(t)=∑_adot P_a(t)P_a(t) is skew adjoint and transports every packet. In the moving frame, the physical Hamiltonian acquires the geometric term - i W(t)^*dot W(t). The leakage estimate must account for the motion of the packet itself. The physical coupling QHP is therefore replaced by Q(t)(H(t)- i K(t))P(t). This is the exact finite distinction between following a moving subspace and remaining in a fixed one.

    Exact mathematical passage
    -\ii W(t)^*\dot W(t)
\dot W^*Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 720

    Differentiate V=W^*U. Since dot W=KW and K^*=-K, dot W^*=-W^*K. Substitution gives the equation. The first term in H_rm mov is self adjoint. The operator - i W^*dot W is self adjoint because W^*dot W is skew adjoint.

    Exact mathematical passage
    
    \dot W^*=-W^*K.
    
\dot xUse in source · 9 passages

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  • Use in source · monograph_atlas.tex, line 398

    vpage22The smaller system remembers the discarded oneAN EXACT QUANTUM MEMORY EQUATIONTraditional edition: Theorem II.9.8, Theorem II.9.11. Choose H=X, initial state (1,0)^T, and retain the first coordinate. The coupled equations and their solution are idot x=y, idot y=x, x(t)=cos t, y(t)=- isin t. The hidden probability returns periodically. Deleting the hidden row and column would instead leave the zero Hamiltonian and predict x(t)=1. vfigmemory headEliminate exactly, not approximately Integrat…

    Exact mathematical passage
    
    \ii\dot x=y,\qquad \ii\dot y=x,\qquad
    x(t)=\cos t,\quad y(t)=-\ii\sin t.
    
\dot yUse in source · 9 passages

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  • Use in source · monograph_atlas.tex, line 218

    1 · 0. Since U^*dot U=J, the coordinate Hamiltonian is H_rm frame=- i J=mat0 · i - i · 0, idot y=H_rm framey. This matrix is Hermitian. Omitting it would predict a constant y, contradicting the displayed coordinates. In this example the norm of the omitted time derivative is exactly one, so the failure is not a small numerical residual.

    Exact mathematical passage
    
    H_{\rm frame}=-\ii J=\mat{0&\ii\\-\ii&0},
    \qquad \ii\dot y=H_{\rm frame}y.
    
\downarrowUse in source · 9 passages

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  • Use in source · monograph_atlas.tex, line 740

    It does not assert a uniform interval width from that argument, a moving time t_N with no extra estimates, or a dimension plateau at every scale. At fixed finite N, d_N(t)→0 as tdownarrow0 and as t→∞. By contrast, first taking N→∞ at positive t and then taking tdownarrow0 yields the continuum dimension. headWhere the infinite tail is controlled At a fixed time, the proof bounds centered modes below by 16k^2 and above by 4π^2k^2. The summable Gaussian dominators control both the heat trace and it…

    Exact mathematical passage
    t\downarrow0
E'Use in source · 2 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 1611

    [Uniform self energy bounds] Let δ=dist(z,Spec D)>0, g=norm B. Then normΣ(z)≤fracg^2δ and normΣ'(z)≤fracg^2δ^2. For real E,E' in an interval at distance at least δ from Spec D, normΣ(E)-Σ(E') ≤ fracg^2δ^2absE-E'.

    Exact mathematical passage
    E,E'
e^{-(t_a+t_b)H}Use in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 431

    nnegative entries and column sums one. Conjugate by the unitary Z. The spectrum and positivity of the quadratic form are preserved, but both off-diagonal entries become -1/4. Thus positivity as an operator is not entrywise positivity and does not by itself give a Markov interpretation. headA useful finite positive kernel For this nonnegative H, vectors u_a and times t_a≥0 satisfy ∑_a,b⟨ u_a,e^-(t_a+t_b)Hu_b⟩ = ∑_a e^-t_aHu_a ^2≥0. The factorization makes positivity transparent. It remains a fini…

    Exact mathematical passage
    
    \sum_{a,b}\langle u_a,e^{-(t_a+t_b)H}u_b\rangle
    =\left\|\sum_a e^{-t_aH}u_a\right\|^2\ge0.
    
\e^{-1/(4t)}Use in source · 3 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 2125

    [Continuum torus small time dimension] Let d_rm torus(t) =-2frac dlog Z_d(t) dlog t. Then d_rm torus(t) = d+O(t^-1 e^-1/(4t)) as tdownarrow0.

    Exact mathematical passage
    
    d_{\rm torus}(t)
    =
     d+O\left(t^{-1}\e^{-1/(4t)}\right)
    
\e^{-16t\abs{k}^2}Use in source · 2 passages

Search aliases: e^-16tabsk^2 e abs mathrm abs

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  • Use in source · Read passage · 02_strengthened.tex, line 2095

    ixed integer mode, [source reference] gives λ_N(k)⟶4π^2absk^2. For centered modes, the inequality sin x≥frac2xπ, 0≤ x≤fracπ2, gives λ_N(k)≥16absk^2. Also λ_N(k)≤4π^2absk^2. Extend the discrete summands by zero outside the centered residue box. The heat trace terms are dominated by e^-16tabsk^2, and the moment terms by 4π^2absk^2 e^-16tabsk^2. Both dominating sequences are summable on Z^d. Dominated convergence proves the two limits. Their quotient gives spectral dimension convergence.

    Exact mathematical passage
    
    \e^{-16t\abs{k}^2},
    
e^{-2\ii t}Use in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 680

    4/5 · 0 · 2. Its memory kernel is K(t)=frac925e^- i t+frac1625e^-2 i t, K(0)=1. Each oscillatory coefficient is positive although K(t) need not be real or pointwise nonnegative. At t=π/2, it equals -16/25-9 i/25. xfigmemory_positive headPositive definite means a matrix test at arbitrary times For retained scalars v_j and real times t_j, the structural identity is ∑_j,koverline v_jK(t_j-t_k)v_k = ∑_k e^ i t_kDB^*v_k ^2≥0. The exact worked check specializes to t=(0,π/2,π) and v=(1,2,-1). Its phase…

    Exact mathematical passage
    
    K(t)=\frac9{25}e^{-\ii t}+\frac{16}{25}e^{-2\ii t},
    \qquad K(0)=1.
    
e^{-2it}Use in source · 1 passage

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  • Use in source · memory_positive.tex, line 7

    weight 16/25; draw[->] (3,1.4)--(5,0.6);draw[->] (9,1.4)--(7,0.6); node[draw,align=center] at (6,0.4) K(t)=(9/25)e^-it+(16/25)e^-2it;

    Exact mathematical passage
    K(t)=(9/25)e^{-it}+(16/25)e^{-2it}
e^{-2\tau}Use in source · 3 passages

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  • Use in source · monograph_atlas.tex, line 422

    vpage23Positive transfer is not a stochastic matrixSPECTRAL POSITIVITY IS BASIS INDEPENDENTTraditional edition: Theorem II.10.1, Theorem II.10.3. For H=I-X, the two eigenvalues are zero and two. Its Euclidean transfer is T(τ)=e^-τ H =frac12mat1+q · 1-q 1-q · 1+q, q=e^-2τ. For τ≥0, the eigenvalues 1,q lie in (0,1], and multiplying two such matrices replaces q,r by qr. This is the semigroup law in spectral coordinates. vfigeuclidean At q=1/2, the displayed T happens also to have nonnegative entrie…

    Exact mathematical passage
    
    T(\tau)=e^{-\tau H}
    =\frac12\mat{1+q&1-q\\1-q&1+q},\qquad q=e^{-2\tau}.
    
\e^{-4\pi^2t\abs{k}^2}Use in source · 3 passages

Search aliases: e^-4π^2tabsk^2 e pi abs mathrm pi abs

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  • Use in source · Read passage · 02_strengthened.tex, line 2061

    [Fixed time heat trace convergence] For every t>0, ∑_k∈Λ_N^* e^-tλ_N(k) ⟶ ∑_k∈ Z^d e^-4π^2tabsk^2 as N→∞. The first spectral moments also converge: ∑_k∈Λ_N^* λ_N(k) e^-tλ_N(k) ⟶ ∑_k∈ Z^d 4π^2absk^2 e^-4π^2tabsk^2. Consequently, the discrete spectral dimensions converge to the continuum torus spectral dimension at every fixed positive time.

    Exact mathematical passage
    
    \sum_{k\in\Lambda_N^*}
    \e^{-t\lambda_N(k)}
    \longrightarrow
    \sum_{k\in\ZZ^d}
    \e^{-4\pi^2t\abs{k}^2}
    
e^{-4\tau}Use in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 442

    vpage24A dimension curve is a scale diagnosticTHE EXACT HEAT TRACE ON FOUR SITESTraditional edition: Definition II.11.1, Proposition II.11.2. For the Laplacian on a cycle with four sites L=2I-S-S^*, the eigenvalues are 0,2,2,4. The normalized heat trace and its diagnostic of spectral dimension are therefore K(τ)=frac1+2e^-2τ+e^-4τ4 =frac(1+e^-2τ)^24, d_s(τ)=-2τfracK'(τ)K(τ) =frac8τe^2τ+1. No numerical differentiation is needed for this finite example. vfigspectral_dimension headBoth ends reflect…

    Exact mathematical passage
    
    K(\tau)=\frac{1+2e^{-2\tau}+e^{-4\tau}}4
    =\frac{(1+e^{-2\tau})^2}4,
    \qquad
     d_s(\tau)=-2\tau\frac{K'(\tau)}{K(\tau)}
    =\frac{8\tau}{e^{2\tau}+1}.
    
\e^{-a(E_j-E_0)}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 1852

    Diagonalize H. Each eigenvalue of T is e^-a(E_j-E_0) and therefore lies in (0,1]. The power law follows from the functional calculus.

    Exact mathematical passage
    
    \e^{-a(E_j-E_0)}
    
\e^{-a(H-E_0I)}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 1838

    Let H=H^* on a nonzero finite dimensional Hilbert space and let E_0=minSpec H. For a lattice time step a>0, define T= e^-a(H-E_0I).

    Exact mathematical passage
    
    T=\e^{-a(H-E_0I)}.
    
\e^{-\abs{n}^2/(4t)}Use in source · 2 passages

Search aliases: e^-absn^2/(4t) e abs mathrm abs

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  • Use in source · Read passage · 02_strengthened.tex, line 2107

    [Theta transformation] The continuum flat torus heat trace satisfies Z_d(t) = ∑_k∈ Z^d e^-4π^2tabsk^2 = (4π t)^-d/2 ∑_n∈ Z^d e^-absn^2/(4t). This is the Poisson summation formula for a Gaussian.

    Exact mathematical passage
    
    Z_d(t)
    =
    \sum_{k\in\ZZ^d}\e^{-4\pi^2t\abs{k}^2}
    =
    (4\pi t)^{-d/2}
    \sum_{n\in\ZZ^d}\e^{-\abs{n}^2/(4t)}.
    
\e^{-aH_T}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 1867

    [Hamiltonian reconstruction from transfer] Let T be positive definite, self adjoint, and contractive. Then H_T=-a^-1log T is a nonnegative self adjoint operator and T^n= e^-naH_T. It is the unique nonnegative self adjoint operator with T= e^-aH_T.

    Exact mathematical passage
    T=\e^{-aH_T}
e^{-H_n}Use in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 797

    For transfers on two states T_n=diag(1,q_n)=e^-H_n, with H_n=diag(0,-log q_n) at unit time, the error in trace norm is 2^-(n+2) and the heat traces converge to 3/2. The criterion for convergence of spectral dimension additionally assumes convergence of the first heat moments in trace norm and a nonzero limiting heat trace. Convergence of the heat trace alone does not determine that quotient. headThe retained evidence and the remaining open targets The extension includes retained exact checks ove…

    Exact mathematical passage
    T_n=\diag(1,q_n)=e^{-H_n}
e^{-i(t-s)H_{QQ}}Use in source · 1 passage

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  • Use in source · Read passage · 01_finite_core.tex, line 973

    idot y · =H_QPx+H_QQy. Solving the second equation gives y(t) =e^-itH_QQy(0) -i∫_0^t e^-i(t-s)H_QQH_QPx(s) ds. Substitution yields the exact Volterra equation idot x(t) = · H_PPx(t) +H_PQe^-itH_QQy(0)

    Exact mathematical passage
    
    y(t)
    =e^{-itH_{QQ}}y(0)
    -i\int_0^t e^{-i(t-s)H_{QQ}}H_{QP}x(s)\,ds.
    
\e^{-\ii sH}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 2445

    The summability condition makes (H_n) Cauchy in operator norm. The limit is self adjoint. Duhamel's identity gives e^- i tH_n- e^- i tH =- i∫_0^t e^- i(t-s)H_n(H_n-H) e^- i sH d s. Both unitary factors have norm one, which gives the first estimate. The same argument gives the Euclidean estimate because the semigroups generated by nonnegative Hamiltonians are contractions.

    Exact mathematical passage
    
    \e^{-\ii tH_n}-\e^{-\ii tH}
    =-\ii\int_0^t
    \e^{-\ii(t-s)H_n}(H_n-H)\e^{-\ii sH}\dd s.
    
\e^{-\ii sH_{\rm d}}Use in source · 1 passage

Search aliases: e^-ii sH_rm d e^- i sH_rm d e ii rm mathrm mathrm rm

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  • Use in source · Read passage · 02_strengthened.tex, line 582

    Let H_rm d=PHP+QHQ, H_rm o=PHQ+QHP. The propagator generated by H_rm d preserves P H and Q H. Duhamel's formula relative to H_rm d gives Q e^- i tHP = - i ∫_0^t Q e^- i(t-s)HH_rm o e^- i sH_rm dP d s. Since H_rm oP=QHP and both propagators are unitary, the norm is at most abstnormQHP. Use [source reference] for the last equality.

    Exact mathematical passage
    
    Q\e^{-\ii tH}P
    =
    -\ii
    \int_0^t
    Q\e^{-\ii(t-s)H}H_{\rm o}\e^{-\ii sH_{\rm d}}P
    \dd s.
    
e^{-\ii t}Use in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 680

    4/5 · 0 · 2. Its memory kernel is K(t)=frac925e^- i t+frac1625e^-2 i t, K(0)=1. Each oscillatory coefficient is positive although K(t) need not be real or pointwise nonnegative. At t=π/2, it equals -16/25-9 i/25. xfigmemory_positive headPositive definite means a matrix test at arbitrary times For retained scalars v_j and real times t_j, the structural identity is ∑_j,koverline v_jK(t_j-t_k)v_k = ∑_k e^ i t_kDB^*v_k ^2≥0. The exact worked check specializes to t=(0,π/2,π) and v=(1,2,-1). Its phase…

    Exact mathematical passage
    
    K(t)=\frac9{25}e^{-\ii t}+\frac{16}{25}e^{-2\ii t},
    \qquad K(0)=1.
    
\e^{-\ii tA}Use in source · 1 passage

Search aliases: e^-ii tA e^- i tA e ii mathrm mathrm

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  • Use in source · Read passage · 02_strengthened.tex, line 1770

    If B=0, the retained and hidden equations decouple. Conversely, suppose that every solution with y(0)=0 satisfies x(t)= e^- i tAx(0). The full block equation gives ddot x(0) = -(A^2+BB^*)x(0), while the declared local equation gives ddot x(0)=-A^2x(0). Since this holds for every retained initial vector, BB^*=0. Hence B=0.

    Exact mathematical passage
    x(t)=\e^{-\ii tA}x(0)
\e^{-\ii tD}Use in source · 3 passages

Search aliases: e^-ii tD e^- i tD e ii mathrm mathrm

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  • Use in source · Read passage · 02_strengthened.tex, line 1680

    [Exact retained memory equation] The retained coordinate satisfies idot x(t) = · Ax(t)+B e^- i tDy(0) · - i∫_0^tK(t-s)x(s) d s, where K(t)=B e^- i tDB^*. For Res>0, ∫_0^∞ e^-stK(t) d t = B(s+ i D)^-1B^*.

    Exact mathematical passage
    
    \begin{aligned}
    \ii\dot x(t)
    ={}&Ax(t)+B\e^{-\ii tD}y(0)\\
    &-\ii\int_0^tK(t-s)x(s)\dd s,
    \end{aligned}
    
e^{-\ii tD}Use in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 696

    A nonzero initial hidden vector also supplies the forcing term Be^- i tDy(0). It is additional data, not part of the convolution kernel. The retained checks cover the displayed kernel values, exact Gram factorization, and acceleration defect. The integral equation follows from the written elimination argument. takeawayMemory is positive definite through a Gram factorization, not through pointwise signs. Exact bare local closure requires the coupling to vanish.

    Exact mathematical passage
    Be^{-\ii tD}y(0)
\e^{-\ii tE_r}Use in source · 1 passage

Search aliases: e^-ii tE_r e^- i tE_r e ii mathrm mathrm

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  • Use in source · Read passage · 02_strengthened.tex, line 1744

    [Finite oscillatory memory expansion] If D=∑_rE_rQ_r is the spectral decomposition of the hidden Hamiltonian, then K(t)=∑_r e^- i tE_rBQ_rB^*. Every coefficient BQ_rB^* is positive semidefinite.

    Exact mathematical passage
    
    K(t)=\sum_r\e^{-\ii tE_r}BQ_rB^*.
    
\e^{-\ii tH}Use in source · 11 passages

Search aliases: e^-ii tH e^- i tH e ii mathrm mathrm

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  • Use in source · Read passage · 02_strengthened.tex, line 525

    [Exact invariant packets] The following conditions are equivalent: item The Hamiltonian commutes with each projector: [H,P_a]=0 for every a. item Transfer blocks between distinct packets vanish: P_bHP_a=0 whenever a≠ b. item Every packet P_a H is invariant under e^- i tH for every real t. When they hold, H=∑_aP_aHP_a and e^- i tH=∑_aP_a e^- i tHP_a.

    Exact mathematical passage
    \e^{-\ii tH}
e^{-\ii tH}Use in source · 3 passages

Search aliases: e^-ii tH e^- i tH ii mathrm

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  • Use in source · monograph_atlas.tex, line 31

    H · Self-adjoint Hamiltonian · It generates evolution in real time through e^- i tH.

    Exact mathematical passage
    e^{-\ii tH}
\e^{-\ii tH_n}Use in source · 4 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 2428

    [Norm summable Hamiltonian tower] Let (H_n) be bounded self adjoint operators on one Hilbert space and assume ∑_n=0^∞normH_n+1-H_n<∞. Then H_n converges in norm to a bounded self adjoint operator H. For every T>0, sup_abs t≤ T norm e^- i tH_n- e^- i tH ≤ TnormH_n-H. If every H_n≥0, then sup_0≤ t≤ T norm e^-tH_n- e^-tH ≤ TnormH_n-H.

    Exact mathematical passage
    
    \sup_{\abs t\leq T}
    \norm{\e^{-\ii tH_n}-\e^{-\ii tH}}
    \leq
    T\norm{H_n-H}.
    
e^{-\ii tH_n}Use in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 779

    For the norm route, work instead on the single fixed space C^2 and set H_n=diag(0,1+2^-n), H=diag(0,1). Here normH_n+1-H_n=2^-(n+1) and normH_n-H=2^-n. The summable tail supplies an error bound for every n. For |t|≤ T, the paper's Duhamel estimate gives norme^- i tH_n-e^- i tH≤ T2^-n. The Euclidean counterpart holds on 0≤ t≤ T because both Hamiltonians are nonnegative. If packet projectors also converge in norm, leakage operators converge uniformly on these time intervals. headExecution scope Ex…

    Exact mathematical passage
    
    \norm{e^{-\ii tH_n}-e^{-\ii tH}}\leq T2^{-n}.
    
\e^{-\ii tH_\ell}Use in source · 1 passage

Search aliases: e^-ii tH_ℓ e^- i tH_ℓ e ii ell mathrm mathrm ell

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  • Use in source · Read passage · 02_strengthened.tex, line 2380

    [Bounded Hamiltonian direct limit] Assume H_ℓ+1R_ℓ=R_ℓ H_ℓ and sup_ℓnormH_ℓ<∞. Then there is a unique bounded self adjoint operator H_∞ on H_∞ such that H_∞ι_ℓ=ι_ℓ H_ℓ for every ℓ. It satisfies e^- i tH_∞ι_ℓ = ι_ℓ e^- i tH_ℓ and e^-tH_∞ι_ℓ = ι_ℓ e^-tH_ℓ when the Hamiltonians are nonnegative.

    Exact mathematical passage
    
    \e^{-\ii tH_\infty}\iota_\ell
    =
    \iota_\ell\e^{-\ii tH_\ell}
    
\e^{-\ii tH_\infty}Use in source · 1 passage

Search aliases: e^-ii tH_∞ e^- i tH_∞ e ii infty mathrm mathrm infty

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  • Use in source · Read passage · 02_strengthened.tex, line 2380

    [Bounded Hamiltonian direct limit] Assume H_ℓ+1R_ℓ=R_ℓ H_ℓ and sup_ℓnormH_ℓ<∞. Then there is a unique bounded self adjoint operator H_∞ on H_∞ such that H_∞ι_ℓ=ι_ℓ H_ℓ for every ℓ. It satisfies e^- i tH_∞ι_ℓ = ι_ℓ e^- i tH_ℓ and e^-tH_∞ι_ℓ = ι_ℓ e^-tH_ℓ when the Hamiltonians are nonnegative.

    Exact mathematical passage
    
    \e^{-\ii tH_\infty}\iota_\ell
    =
    \iota_\ell\e^{-\ii tH_\ell}
    
\e^{-\ii(t-s)D}Use in source · 1 passage

Search aliases: e^-ii(t-s)D e^- i(t-s)D e ii mathrm mathrm

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  • Use in source · Read passage · 02_strengthened.tex, line 1705

    The hidden equation is idot y=B^*x+Dy. Variation of constants gives y(t)= e^- i tDy(0) - i∫_0^t e^- i(t-s)DB^*x(s) d s. Substitute into idot x=Ax+By. The Laplace formula follows by diagonalizing D or integrating the norm convergent finite dimensional exponential.

    Exact mathematical passage
    
    y(t)=\e^{-\ii tD}y(0)
    -\ii\int_0^t\e^{-\ii(t-s)D}B^*x(s)\dd s.
    
\e^{-\ii(t-s)H}Use in source · 1 passage

Search aliases: e^-ii(t-s)H e^- i(t-s)H e ii mathrm mathrm

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  • Use in source · Read passage · 02_strengthened.tex, line 582

    Let H_rm d=PHP+QHQ, H_rm o=PHQ+QHP. The propagator generated by H_rm d preserves P H and Q H. Duhamel's formula relative to H_rm d gives Q e^- i tHP = - i ∫_0^t Q e^- i(t-s)HH_rm o e^- i sH_rm dP d s. Since H_rm oP=QHP and both propagators are unitary, the norm is at most abstnormQHP. Use [source reference] for the last equality.

    Exact mathematical passage
    
    Q\e^{-\ii tH}P
    =
    -\ii
    \int_0^t
    Q\e^{-\ii(t-s)H}H_{\rm o}\e^{-\ii sH_{\rm d}}P
    \dd s.
    
\e^{-\ii(t-s)H_n}Use in source · 1 passage

Search aliases: e^-ii(t-s)H_n e^- i(t-s)H_n e ii mathrm mathrm

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  • Use in source · Read passage · 02_strengthened.tex, line 2445

    The summability condition makes (H_n) Cauchy in operator norm. The limit is self adjoint. Duhamel's identity gives e^- i tH_n- e^- i tH =- i∫_0^t e^- i(t-s)H_n(H_n-H) e^- i sH d s. Both unitary factors have norm one, which gives the first estimate. The same argument gives the Euclidean estimate because the semigroups generated by nonnegative Hamiltonians are contractions.

    Exact mathematical passage
    
    \e^{-\ii tH_n}-\e^{-\ii tH}
    =-\ii\int_0^t
    \e^{-\ii(t-s)H_n}(H_n-H)\e^{-\ii sH}\dd s.
    
\e^{-\ii(t_j-t_k)D}Use in source · 1 passage

Search aliases: e^-ii(t_j-t_k)D e^- i(t_j-t_k)D e ii mathrm mathrm

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  • Use in source · Read passage · 02_strengthened.tex, line 1727

    Set w=∑_k=1^m e^ i t_kDB^*v_k. Then norm w^2 = ∑_j,k ipB^*v_j e^- i(t_j-t_k)DB^*v_k = ∑_j,k ipv_jK(t_j-t_k)v_k.

    Exact mathematical passage
    
    \norm w^2
    =
    \sum_{j,k}
    \ip{B^*v_j}{\e^{-\ii(t_j-t_k)D}B^*v_k}
    =
    \sum_{j,k}
    \ip{v_j}{K(t_j-t_k)v_k}.
    
e^{-\ii\pi L/2}Use in source · 2 passages

Search aliases: e^-iiπ L/2 e^- iπ L/2 ii pi mathrm pi

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  • Use in source · monograph_atlas.tex, line 495

    lculation of transfer to the opposite siteSEEDS, CHARACTERS, INTERFERENCE, AND DEPHASINGTraditional edition: Corollary II.3.3, Theorem II.4.4, Theorem II.7.4. Return to the shift on four sites S and Laplacian L=2I-S-S^*. The same character projectors have energies (0,2,4,2). At time t=π/2, their evolution phases are (1,-1,1,-1), exactly the character eigenvalues of S^2. Hence e^- iπ L/2=S^2, ket0⟼ket2. vfigperfect_transfer At halfway time π/4, the actual amplitude vector is (- i,1, i,1)^T/2, giv…

    Exact mathematical passage
    
    e^{-\ii\pi L/2}=S^2,\qquad
    \ket0\longmapsto\ket2.
    
e^{-it}Use in source · 1 passage

Search aliases: e^-it

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  • Use in source · memory_positive.tex, line 7

    weight 16/25; draw[->] (3,1.4)--(5,0.6);draw[->] (9,1.4)--(7,0.6); node[draw,align=center] at (6,0.4) K(t)=(9/25)e^-it+(16/25)e^-2it;

    Exact mathematical passage
    K(t)=(9/25)e^{-it}+(16/25)e^{-2it}
e^{-itH_{QQ}}Use in source · 3 passages

Search aliases: e^-itH_QQ

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  • Use in source · Read passage · 01_finite_core.tex, line 973

    idot y · =H_QPx+H_QQy. Solving the second equation gives y(t) =e^-itH_QQy(0) -i∫_0^t e^-i(t-s)H_QQH_QPx(s) ds. Substitution yields the exact Volterra equation idot x(t) = · H_PPx(t) +H_PQe^-itH_QQy(0)

    Exact mathematical passage
    
    y(t)
    =e^{-itH_{QQ}}y(0)
    -i\int_0^t e^{-i(t-s)H_{QQ}}H_{QP}x(s)\,ds.
    
\e^{-na(E_j-E_0)}Use in source · 1 passage

Search aliases: e^-na(E_j-E_0) e mathrm

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  • Use in source · Read passage · 02_strengthened.tex, line 1934

    In the spectral decomposition, T^n-P_0 has eigenvalues zero on the ground space and e^-na(E_j-E_0) on the excited eigenspaces. The largest is e^-naΔ.

    Exact mathematical passage
    \e^{-na(E_j-E_0)}
\e^{-na(H-E_0I)}Use in source · 1 passage

Search aliases: e^-na(H-E_0I) e mathrm

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  • Use in source · Read passage · 02_strengthened.tex, line 1844

    [Finite Euclidean transfer] The operator T is positive definite, self adjoint, and contractive. Its spectrum lies in (0,1], and T^n= e^-na(H-E_0I) for every n∈ N.

    Exact mathematical passage
    
    T^n=\e^{-na(H-E_0I)}
    
\e^{-naH_T}Use in source · 1 passage

Search aliases: e^-naH_T e mathrm

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  • Use in source · Read passage · 02_strengthened.tex, line 1864

    [Hamiltonian reconstruction from transfer] Let T be positive definite, self adjoint, and contractive. Then H_T=-a^-1log T is a nonnegative self adjoint operator and T^n= e^-naH_T. It is the unique nonnegative self adjoint operator with T= e^-aH_T.

    Exact mathematical passage
    
    T^n=\e^{-naH_T}.
    
\e^{-na\Delta}Use in source · 2 passages

Search aliases: e^-naΔ e Delta mathrm Delta

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  • Use in source · Read passage · 02_strengthened.tex, line 1928

    [Ground packet convergence] Let P_0 be the spectral projector of H at E_0, and let Δ=min{E_j-E_0:E_j>E_0}. If an excited eigenvalue exists, then normT^n-P_0= e^-naΔ.

    Exact mathematical passage
    
    \norm{T^n-P_0}=\e^{-na\Delta}.
    
\e^{-st}Use in source · 1 passage

Search aliases: e^-st e mathrm

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  • Use in source · Read passage · 02_strengthened.tex, line 1692

    · - i∫_0^tK(t-s)x(s) d s, where K(t)=B e^- i tDB^*. For Res>0, ∫_0^∞ e^-stK(t) d t = B(s+ i D)^-1B^*.

    Exact mathematical passage
    
    \int_0^\infty\e^{-st}K(t)\dd t
    =
    B(s+\ii D)^{-1}B^*.
    
e^{-t(H-E_0I)}Use in source · 1 passage

Search aliases: e^-t(H-E_0I)

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  • Use in source · monograph_atlas.tex, line 714

    For a family with nontrivial excited spectra, a uniform exponential rate needs a common positive lower bound on the gap. Ground multiplicity does not cause a problem: P_0 selects the entire eigenspace at the minimum energy. For a Hamiltonian whose minimum is E_0≠0, the normalized transfer is e^-t(H-E_0I) before taking the limit. headPositivity is retained at several Euclidean times For arbitrary vectors u_j and nonnegative integer times n_j, the reflected kernel obeys ∑_j,k⟨ u_j,T^n_j+n_ku_k⟩ = …

    Exact mathematical passage
    e^{-t(H-E_0I)}
e^{-t(x-e)}Use in source · 2 passages

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  • Use in source · Read passage · 03_supplement_03.tex, line 143

    Connecting power series and spectral calculus. The shifted generator is proved Hermitian. The implementation then identifies the actual matrix exponential with continuous functional calculus: T_e(t)=f_t(H), f_t(x)=e^-t(x-e). The formal proof uses composition, scalar multiplication, subtraction, and the established agreement between the exponential in functional calculus and the exponential defined by a power series. Spectral mapping is consequently available for the operator that was actually de…

    Exact mathematical passage
    
    \boxed{T_e(t)=f_t(H),\qquad f_t(x)=e^{-t(x-e)}.}
    
e^{-t_aH}Use in source · 1 passage

Search aliases: e^-t_aH

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  • Use in source · monograph_atlas.tex, line 431

    nnegative entries and column sums one. Conjugate by the unitary Z. The spectrum and positivity of the quadratic form are preserved, but both off-diagonal entries become -1/4. Thus positivity as an operator is not entrywise positivity and does not by itself give a Markov interpretation. headA useful finite positive kernel For this nonnegative H, vectors u_a and times t_a≥0 satisfy ∑_a,b⟨ u_a,e^-(t_a+t_b)Hu_b⟩ = ∑_a e^-t_aHu_a ^2≥0. The factorization makes positivity transparent. It remains a fini…

    Exact mathematical passage
    
    \sum_{a,b}\langle u_a,e^{-(t_a+t_b)H}u_b\rangle
    =\left\|\sum_a e^{-t_aH}u_a\right\|^2\ge0.
    
\e^{-tH}Use in source · 1 passage

Search aliases: e^-tH e mathrm

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  • Use in source · Read passage · 02_strengthened.tex, line 2435

    Let (H_n) be bounded self adjoint operators on one Hilbert space and assume ∑_n=0^∞normH_n+1-H_n<∞. Then H_n converges in norm to a bounded self adjoint operator H. For every T>0, sup_abs t≤ T norm e^- i tH_n- e^- i tH ≤ TnormH_n-H. If every H_n≥0, then sup_0≤ t≤ T norm e^-tH_n- e^-tH ≤ TnormH_n-H.

    Exact mathematical passage
    
    \sup_{0\leq t\leq T}
    \norm{\e^{-tH_n}-\e^{-tH}}
    \leq
    T\norm{H_n-H}.
    
\e^{-tH_n}Use in source · 1 passage

Search aliases: e^-tH_n e mathrm

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  • Use in source · Read passage · 02_strengthened.tex, line 2435

    Let (H_n) be bounded self adjoint operators on one Hilbert space and assume ∑_n=0^∞normH_n+1-H_n<∞. Then H_n converges in norm to a bounded self adjoint operator H. For every T>0, sup_abs t≤ T norm e^- i tH_n- e^- i tH ≤ TnormH_n-H. If every H_n≥0, then sup_0≤ t≤ T norm e^-tH_n- e^-tH ≤ TnormH_n-H.

    Exact mathematical passage
    
    \sup_{0\leq t\leq T}
    \norm{\e^{-tH_n}-\e^{-tH}}
    \leq
    T\norm{H_n-H}.
    
\e^{-tH_\ell}Use in source · 1 passage

Search aliases: e^-tH_ℓ e ell mathrm ell

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  • Use in source · Read passage · 02_strengthened.tex, line 2386

    imit] Assume H_ℓ+1R_ℓ=R_ℓ H_ℓ and sup_ℓnormH_ℓ<∞. Then there is a unique bounded self adjoint operator H_∞ on H_∞ such that H_∞ι_ℓ=ι_ℓ H_ℓ for every ℓ. It satisfies e^- i tH_∞ι_ℓ = ι_ℓ e^- i tH_ℓ and e^-tH_∞ι_ℓ = ι_ℓ e^-tH_ℓ when the Hamiltonians are nonnegative.

    Exact mathematical passage
    
    \e^{-tH_\infty}\iota_\ell
    =
    \iota_\ell\e^{-tH_\ell}
    
\e^{-tH_\infty}Use in source · 1 passage

Search aliases: e^-tH_∞ e infty mathrm infty

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  • Use in source · Read passage · 02_strengthened.tex, line 2386

    imit] Assume H_ℓ+1R_ℓ=R_ℓ H_ℓ and sup_ℓnormH_ℓ<∞. Then there is a unique bounded self adjoint operator H_∞ on H_∞ such that H_∞ι_ℓ=ι_ℓ H_ℓ for every ℓ. It satisfies e^- i tH_∞ι_ℓ = ι_ℓ e^- i tH_ℓ and e^-tH_∞ι_ℓ = ι_ℓ e^-tH_ℓ when the Hamiltonians are nonnegative.

    Exact mathematical passage
    
    \e^{-tH_\infty}\iota_\ell
    =
    \iota_\ell\e^{-tH_\ell}
    
\e^{-tL_n}Use in source · 3 passages

Search aliases: e^-tL_n e mathrm

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  • Use in source · Read passage · 02_strengthened.tex, line 2512

    [Heat trace convergence from trace norm] Let L_n,L be nonnegative self adjoint operators on one Hilbert space. For a fixed t>0, assume their heat operators are trace class and that e^-tL_n⟶ e^-tL in trace norm. Then Tr( e^-tL_n)⟶Tr( e^-tL). If also the heat moment operators are trace class and L_n e^-tL_n⟶ L e^-tL in trace norm and the limiting heat trace is nonzero, then the spectral dimensions defined by the heat moment ratio converge at that time.

    Exact mathematical passage
    
    \e^{-tL_n}\longrightarrow\e^{-tL}
    
e^{-t\lambda}Use in source · 1 passage

Search aliases: e^-tλ lambda

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  • Use in source · monograph_atlas.tex, line 728

    At the single time t=log2/16, two small grids admit exact rational heat weights: c|c|c|c|c N · spectrum · Z_N · ∑λ e^-tλ · d_N/log2 2 · (0,16) · 3/2 · 8 · 2/3 4 · (0,32,32,64) · 25/16 · 20 · 8/5 These are unnormalized traces. Normalizing by N changes Z_N but leaves the logarithmic derivative at that fixed grid unchanged. xfigheat_limits headThe theorem uses two separate choices For each ε>0, first choose a fixed positive time t_ε so that the continuum torus dimension differs from one by less tha…

    Exact mathematical passage
    
    \begin{array}{c|c|c|c|c}
    N&\text{spectrum}&Z_N&\sum\lambda e^{-t\lambda}&d_N/\log2\\\hline
    2&(0,16)&3/2&8&2/3\\
    4&(0,32,32,64)&25/16&20&8/5
    \end{array}
    
\e^{-t\lambda_N(k)}Use in source · 2 passages

Search aliases: e^-tλ_N(k) e lambda mathrm lambda

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  • Use in source · Read passage · 02_strengthened.tex, line 2061

    [Fixed time heat trace convergence] For every t>0, ∑_k∈Λ_N^* e^-tλ_N(k) ⟶ ∑_k∈ Z^d e^-4π^2tabsk^2 as N→∞. The first spectral moments also converge: ∑_k∈Λ_N^* λ_N(k) e^-tλ_N(k) ⟶ ∑_k∈ Z^d 4π^2absk^2 e^-4π^2tabsk^2. Consequently, the discrete spectral dimensions converge to the continuum torus spectral dimension at every fixed positive time.

    Exact mathematical passage
    
    \sum_{k\in\Lambda_N^*}
    \e^{-t\lambda_N(k)}
    \longrightarrow
    \sum_{k\in\ZZ^d}
    \e^{-4\pi^2t\abs{k}^2}
    
e^{-t\lambda_N(k)}Use in source · 2 passages

Search aliases: e^-tλ_N(k) lambda

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  • Use in source · monograph_atlas.tex, line 725

    vpage37The dimension window has an order of limitsFINITE HEAT DATA AND THE QUANTIFIERSTraditional edition: Theorem II.11.5, Corollary II.11.8. For the unit circle grid with N sites, the scaled eigenvalues are λ_N(k)=4N^2sin^2(π k/N). Put Z_N(t)=∑_ke^-tλ_N(k) and d_N(t)=2t∑_kλ_N(k)e^-tλ_N(k)/Z_N(t).

    Exact mathematical passage
    Z_N(t)=\sum_ke^{-t\lambda_N(k)}
e^{-\tau H}Use in source · 1 passage

Search aliases: e^-τ H tau

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  • Use in source · monograph_atlas.tex, line 422

    vpage23Positive transfer is not a stochastic matrixSPECTRAL POSITIVITY IS BASIS INDEPENDENTTraditional edition: Theorem II.10.1, Theorem II.10.3. For H=I-X, the two eigenvalues are zero and two. Its Euclidean transfer is T(τ)=e^-τ H =frac12mat1+q · 1-q 1-q · 1+q, q=e^-2τ. For τ≥0, the eigenvalues 1,q lie in (0,1], and multiplying two such matrices replaces q,r by qr. This is the semigroup law in spectral coordinates. vfigeuclidean At q=1/2, the displayed T happens also to have nonnegative entrie…

    Exact mathematical passage
    
    T(\tau)=e^{-\tau H}
    =\frac12\mat{1+q&1-q\\1-q&1+q},\qquad q=e^{-2\tau}.
    
e^{-\tau(E_j-E_0)}Use in source · 1 passage

Search aliases: e^-τ(E_j-E_0) tau

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  • Use in source · Read passage · 01_finite_core.tex, line 1072

    Diagonalize H=∑_jE_jP_j. Then T(τ)=∑_j e^-τ(E_j-E_0)P_j. Every eigenvalue is strictly positive and at most one. Multiplication adds the exponents, proving the semigroup law and T(0)=I. Positivity here is operator positivity, not an assertion that every matrix entry is nonnegative.

    Exact mathematical passage
    
    T(\tau)=\sum_j e^{-\tau(E_j-E_0)}P_j.
    
e^{-\tau(H-E_0I)}Use in source · 1 passage

Search aliases: e^-τ(H-E_0I) tau

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  • Use in source · Read passage · 01_finite_core.tex, line 1056

    [Finite Euclidean transfer] Let H be Hermitian on a nonzero finite-dimensional Hilbert space. For all real τ,σ≥0, T(τ)=e^-τ(H-E_0I), E_0=minSpec H, is positive definite and satisfies T(τ+σ)=T(τ)T(σ). Its spectrum is contained in (0,1].

    Exact mathematical passage
    
    T(\tau)=e^{-\tau(H-E_0I)},
    \qquad
    E_0=\min\Spec H,
    
e^{-\tau\lambda_j}Use in source · 2 passages

Search aliases: e^-τλ_j tau lambda

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  • Use in source · Read passage · 01_finite_core.tex, line 1116

    Let L≥0 be a finite Laplacian on N≥1 states, with eigenvalues λ_j and at least one zero eigenvalue. For diffusion time τ>0, define the normalized heat trace K(τ)=frac1N∑_j e^-τλ_j and the scale-dependent spectral dimension d_s(τ) =-2fracdlog K(τ)dlogτ. For a finite system, d_s(τ) is a diagnostic, not a topological invariant. Indeed, finite differentiation gives d_s(τ)=2τ frac∑_jλ_j e^-τλ_j∑_j e^-τλ_j. It tends to zero as τdownarrow0 and, under the stated assumption of a zero mode, as τ→∞. If a g…

    Exact mathematical passage
    
    K(\tau)=\frac1N\sum_j e^{-\tau\lambda_j}
    
e^{2\pi i/N}Use in source · 1 passage

Search aliases: e^2π i/N pi

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  • Use in source · Read passage · 01_finite_core.tex, line 192

    Let N≥1 be an integer, and let S be a unitary symmetry whose order divides N: S^N=I. Set ω=e^2π i/N.

    Exact mathematical passage
    \omega=e^{2\pi i/N}
\e^{2\pi\ii/N}Use in source · 1 passage

Search aliases: e^2πii/N e^2π i/N e pi ii mathrm pi mathrm

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e^{2\tau}Use in source · 1 passage

Search aliases: e^2τ tau

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  • Use in source · monograph_atlas.tex, line 442

    vpage24A dimension curve is a scale diagnosticTHE EXACT HEAT TRACE ON FOUR SITESTraditional edition: Definition II.11.1, Proposition II.11.2. For the Laplacian on a cycle with four sites L=2I-S-S^*, the eigenvalues are 0,2,2,4. The normalized heat trace and its diagnostic of spectral dimension are therefore K(τ)=frac1+2e^-2τ+e^-4τ4 =frac(1+e^-2τ)^24, d_s(τ)=-2τfracK'(τ)K(τ) =frac8τe^2τ+1. No numerical differentiation is needed for this finite example. vfigspectral_dimension headBoth ends reflect…

    Exact mathematical passage
    
    K(\tau)=\frac{1+2e^{-2\tau}+e^{-4\tau}}4
    =\frac{(1+e^{-2\tau})^2}4,
    \qquad
     d_s(\tau)=-2\tau\frac{K'(\tau)}{K(\tau)}
    =\frac{8\tau}{e^{2\tau}+1}.
    
\e^{\ii t_kD}Use in source · 1 passage

Search aliases: e^ii t_kD e^ i t_kD e ii mathrm mathrm

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  • Use in source · Read passage · 02_strengthened.tex, line 1723

    Set w=∑_k=1^m e^ i t_kDB^*v_k. Then norm w^2 = ∑_j,k ipB^*v_j e^- i(t_j-t_k)DB^*v_k = ∑_j,k ipv_jK(t_j-t_k)v_k.

    Exact mathematical passage
    
    w=\sum_{k=1}^{m}\e^{\ii t_kD}B^*v_k.
    
e^{\ii t_kD}Use in source · 1 passage

Search aliases: e^ii t_kD e^ i t_kD ii mathrm

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  • Use in source · monograph_atlas.tex, line 688

    ts memory kernel is K(t)=frac925e^- i t+frac1625e^-2 i t, K(0)=1. Each oscillatory coefficient is positive although K(t) need not be real or pointwise nonnegative. At t=π/2, it equals -16/25-9 i/25. xfigmemory_positive headPositive definite means a matrix test at arbitrary times For retained scalars v_j and real times t_j, the structural identity is ∑_j,koverline v_jK(t_j-t_k)v_k = ∑_k e^ i t_kDB^*v_k ^2≥0. The exact worked check specializes to t=(0,π/2,π) and v=(1,2,-1). Its phases lie in QQ( i…

    Exact mathematical passage
    
    \sum_{j,k}\overline v_jK(t_j-t_k)v_k
    =\left\|\sum_k e^{\ii t_kD}B^*v_k\right\|^2\geq0.
    
e^{\ii\phi}Use in source · 1 passage

Search aliases: e^iiϕ e^ iϕ ii phi mathrm phi

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  • Use in source · monograph_atlas.tex, line 283

    n·σ). This is a smooth rank-one orthogonal projector. The intrinsic curvature is the endomorphism-valued two-form P( d Pwedge d P)P. With the paper's scalar convention, its component is F_θϕ=- iTr (P[∂_θ P,∂_ϕ P]) =frac12sinθ. vfigbloch_curvature headA local frame gives the same answer Away from the south pole, use u_N=(cos(θ/2),e^ iϕsin(θ/2))^T. Then P=u_Nu_N^* and the scalar one-form is A_N=- i u_N^* d u_N=frac1-cosθ2 dϕ, d A_N=frac12sinθ dθwedge dϕ. Thus the curvature flux through the cap 0≤θ…

    Exact mathematical passage
    u_N=(\cos(\theta/2),e^{\ii\phi}\sin(\theta/2))^T
e^{isH}Use in source · 2 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 442

    Set F(s)=e^isHPe^-isH. Differentiating the exponential gives F'(s)=i e^isH[H,P]e^-isH, F(0)=P. Unitary conjugation preserves the operator norm, so F'(s) = [H,P] . The mean-value estimate on the interval between 0 and t yields F(t)-P ≤ |t| [H,P] . Finally, e^itHQe^-itHP=(P-F(t))P and P ≤1. Left multiplication by e^itH preserves the norm and gives the desired inequality. This argument includes positive, negative and zero time.

    Exact mathematical passage
    F(s)=e^{isH}Pe^{-isH}
e^{itH}Use in source · 2 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 450

    Set F(s)=e^isHPe^-isH. Differentiating the exponential gives F'(s)=i e^isH[H,P]e^-isH, F(0)=P. Unitary conjugation preserves the operator norm, so F'(s) = [H,P] . The mean-value estimate on the interval between 0 and t yields F(t)-P ≤ |t| [H,P] . Finally, e^itHQe^-itHP=(P-F(t))P and P ≤1. Left multiplication by e^itH preserves the norm and gives the desired inequality. This argument includes positive, negative and zero time.

    Exact mathematical passage
    e^{itH}Qe^{-itH}P=(P-F(t))P
\e^{t\Gcal}Use in source · 2 passages

Search aliases: e^tGcal e^t G e Gcal mathrm mathcal

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  • Use in source · Read passage · 02_strengthened.tex, line 1244

    a Lindblad generator] Let S be unitary and N≥1 an integer with S^N=I. Assume SHS^*=H and, for every jump operator, there is a charge q_r such that SL_rS^*=ω^q_rL_r. Then the Lindblad generator G preserves every coherence order: G L_p= L_p G. The quantum dynamical semigroup e^t G has the same property.

    Exact mathematical passage
    \e^{t\Gcal}
e^{zH}Use in source · 2 passages

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  • Use in source · Read passage · 03_supplement_01.tex, line 59

    Symmetry and measurement. Exact symmetry: source Theorem 5.1. If HP_a=P_aH for every packet, then P_bHP_a=0 (b≠ a), H=∑_aP_aHP_a. In a complex Banach algebra, commutation also propagates to the actual exponential: e^zHP_a=P_ae^zH (z∈ C). Consequently, e^zH=∑_aP_ae^zHP_a, P_be^zHP_a=0 (b≠ a). Taking z=-it gives evolution in real time. The Lean proof applies the exponential commutation theorem directly, so invariance of the packets is a proved consequence of commutation. Self-adjointness of H is n…

    Exact mathematical passage
    
    e^{zH}P_a=P_ae^{zH}\qquad(z\in\C).
    
E_0Use in source · 17 passages

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  • Use in source · monograph_atlas.tex, line 714

    For a family with nontrivial excited spectra, a uniform exponential rate needs a common positive lower bound on the gap. Ground multiplicity does not cause a problem: P_0 selects the entire eigenspace at the minimum energy. For a Hamiltonian whose minimum is E_0≠0, the normalized transfer is e^-t(H-E_0I) before taking the limit. headPositivity is retained at several Euclidean times For arbitrary vectors u_j and nonnegative integer times n_j, the reflected kernel obeys ∑_j,k⟨ u_j,T^n_j+n_ku_k⟩ = …

    Exact mathematical passage
    E_0\ne0
E_0^*Use in source · 1 passage

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  • Use in source · Read passage · 03_supplement_05.tex, line 211

    A genuine channel can still be uncorrectable. For full qubit dephasing, E_0=diag(1,0) and E_1=diag(0,1), the Kraus normalization is checked. But E_0^*E_0 cannot be a scalar multiple of I, as its two diagonal entries differ. Necessity therefore proves that no finite recovery channel corrects the full code space. The case of the zero code is also checked independently.

    Exact mathematical passage
    E_0^*E_0
E_1Use in source · 5 passages

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  • Use in source · monograph_atlas.tex, line 597

    vpage32Null Gram directions are removed before recoveryA TOTAL CHANNEL FROM SINGULAR ERROR DATATraditional edition: Theorem II.8.3, Theorem II.8.4. Let HH= C^3, with nonzero code projector P=diag(1,1,0). On the code use the error family E_1=(3/5)P, E_2=(4/5)P, and E_3=0. Its Knill--Laflamme Gram matrix is c=frac125mat9 · 12 · 0

    Exact mathematical passage
    E_1=(3/5)P
E_{12}Use in source · 2 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 1217

    ty gives A_ABΠ^phys=0, Π^phys A_ABΠ^phys=0 automatically. This compression therefore cannot certify operator closure away from the physical range. A nonzero measured compression contradicts the exact-kernel assumptions or indicates an approximation or implementation error. For example, C_1=diag(1,0,0) and C_2=E_12+E_21 annihilate the same third coordinate, while their commutator E_12-E_21 is nonzero. With zero proposed structure coefficients, the anomaly is nonzero but its physical compression v…

    Exact mathematical passage
    C_2=E_{12}+E_{21}
E_2Use in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 597

    vpage32Null Gram directions are removed before recoveryA TOTAL CHANNEL FROM SINGULAR ERROR DATATraditional edition: Theorem II.8.3, Theorem II.8.4. Let HH= C^3, with nonzero code projector P=diag(1,1,0). On the code use the error family E_1=(3/5)P, E_2=(4/5)P, and E_3=0. Its Knill--Laflamme Gram matrix is c=frac125mat9 · 12 · 0

    Exact mathematical passage
    E_2=(4/5)P
E_{21}Use in source · 2 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 1217

    ty gives A_ABΠ^phys=0, Π^phys A_ABΠ^phys=0 automatically. This compression therefore cannot certify operator closure away from the physical range. A nonzero measured compression contradicts the exact-kernel assumptions or indicates an approximation or implementation error. For example, C_1=diag(1,0,0) and C_2=E_12+E_21 annihilate the same third coordinate, while their commutator E_12-E_21 is nonzero. With zero proposed structure coefficients, the anomaly is nonzero but its physical compression v…

    Exact mathematical passage
    C_2=E_{12}+E_{21}
E_3Use in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 597

    vpage32Null Gram directions are removed before recoveryA TOTAL CHANNEL FROM SINGULAR ERROR DATATraditional edition: Theorem II.8.3, Theorem II.8.4. Let HH= C^3, with nonzero code projector P=diag(1,1,0). On the code use the error family E_1=(3/5)P, E_2=(4/5)P, and E_3=0. Its Knill--Laflamme Gram matrix is c=frac125mat9 · 12 · 0

    Exact mathematical passage
    E_3=0
E_{ab}Use in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 70

    For the exact calculation, apply the four matrix units E_ab to each seed matrix, flatten the outputs, and compute their column rank. The observed dimensions are two and four, respectively. The calculation directly exhibits the independent rows counted by the theorem. takeawaySchmidt rank measures the remote multiplicity directions accessible to the local operator span. It is not permission for unrestricted deterministic local state preparation.

    Exact mathematical passage
    E_{ab}
E_b^*Use in source · 1 passage

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  • Use in source · Read passage · 03_supplement_05.tex, line 169

    Cross terms for the original errors. For arbitrary positive Gram data, the same recovery satisfies R(E_aρ E_b^*)=C_baρ (Pρ P=ρ). The index order ba is intentional: the defining Gram relation is PE_a^*E_bP=C_abP. The proof first derives scalar corrected Kraus composites for the constructed recovery and then uses its trace-preserving completeness to identify the original Gram entries.

    Exact mathematical passage
    
    \boxed{\mathcal R(E_a\rho E_b^*)=C_{ba}\rho\qquad(P\rho P=\rho).}
    
E_{ii}^{\lambda}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 259

    x an irreducible unitary representation π_λ:G→ U(d_λ) and an orthonormal basis of its representation space. Define E_ij^λ = fracd_λabsG ∑_g∈ G [π_λ(g^-1)]_jiU(g). Then E_ij^λE_kℓ^μ = δ_λμδ_jkE_iℓ^λ, (E_ij^λ)^*=E_ji^λ, and P_λ=∑_i=1^d_λE_ii^λ.

    Exact mathematical passage
    
    P_\lambda=\sum_{i=1}^{d_\lambda}E_{ii}^{\lambda}.
    
E_{ij}^{\lambda}Use in source · 2 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 243

    [Representation matrix units] Fix an irreducible unitary representation π_λ:G→ U(d_λ) and an orthonormal basis of its representation space. Define E_ij^λ = fracd_λabsG ∑_g∈ G [π_λ(g^-1)]_jiU(g). Then E_ij^λE_kℓ^μ = δ_λμδ_jkE_iℓ^λ, (E_ij^λ)^*=E_ji^λ, and P_λ=∑_i=1^d_λE_ii^λ.

    Exact mathematical passage
    
    E_{ij}^{\lambda}
    =
    \frac{d_\lambda}{\abs{G}}
    \sum_{g\in G}
    \bigl[\pi_\lambda(g^{-1})\bigr]_{ji}U(g).
    
E_{i\ell}^{\lambda}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 251

    [Representation matrix units] Fix an irreducible unitary representation π_λ:G→ U(d_λ) and an orthonormal basis of its representation space. Define E_ij^λ = fracd_λabsG ∑_g∈ G [π_λ(g^-1)]_jiU(g). Then E_ij^λE_kℓ^μ = δ_λμδ_jkE_iℓ^λ, (E_ij^λ)^*=E_ji^λ, and P_λ=∑_i=1^d_λE_ii^λ.

    Exact mathematical passage
    
    E_{ij}^{\lambda}E_{k\ell}^{\mu}
    =
    \delta_{\lambda\mu}\delta_{jk}E_{i\ell}^{\lambda},
    \qquad
    \bigl(E_{ij}^{\lambda}\bigr)^*=E_{ji}^{\lambda},
    
E_jUse in source · 6 passages

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  • Use in source · Read passage · monograph_examples.tex, line 17

    resolvent elimination give different results. Normalization changes the map. Let P=|0⟩⟨0| on C^2 and Z=diag(1,-1). The normalized Kraus family sqrt3/4 I, sqrt1/4 Z satisfies ∑_j K_j^*K_j=I and maps P to P. The unnormalized family sqrt3 I, Z satisfies ∑_j E_j^*E_j=4I and maps P to 4P. The two families have the same relative weights, but their total normalization differs. Both outputs are proportional to the same projector, but their traces differ. [H]centering includegraphics[width=.94textwidth]m…

    Exact mathematical passage
    \sum_j E_j^*E_j=4I
e_jUse in source · 2 passages

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  • Use in source · Read passage · 03_supplement_02.tex, line 17

    0 · x≠ a. The seed is ψ_0=ket0. Define a translation operator by (T_a v)(x)=v(x-a). At position j, the local Pauli X is X_j=T_e_j, where e_j has a single nonzero binary coordinate. The formal circuit uses the identity when a_j=0 and X_j when a_j=1.

    Exact mathematical passage
    X_j=T_{e_j}
E_j^*Use in source · 1 passage

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  • Use in source · Read passage · monograph_examples.tex, line 17

    resolvent elimination give different results. Normalization changes the map. Let P=|0⟩⟨0| on C^2 and Z=diag(1,-1). The normalized Kraus family sqrt3/4 I, sqrt1/4 Z satisfies ∑_j K_j^*K_j=I and maps P to P. The unnormalized family sqrt3 I, Z satisfies ∑_j E_j^*E_j=4I and maps P to 4P. The two families have the same relative weights, but their total normalization differs. Both outputs are proportional to the same projector, but their traces differ. [H]centering includegraphics[width=.94textwidth]m…

    Exact mathematical passage
    \sum_j E_j^*E_j=4I
E_{ji}^{\lambda}Use in source · 1 passage

Search aliases: E_ji^λ lambda

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  • Use in source · Read passage · 02_strengthened.tex, line 251

    [Representation matrix units] Fix an irreducible unitary representation π_λ:G→ U(d_λ) and an orthonormal basis of its representation space. Define E_ij^λ = fracd_λabsG ∑_g∈ G [π_λ(g^-1)]_jiU(g). Then E_ij^λE_kℓ^μ = δ_λμδ_jkE_iℓ^λ, (E_ij^λ)^*=E_ji^λ, and P_λ=∑_i=1^d_λE_ii^λ.

    Exact mathematical passage
    
    E_{ij}^{\lambda}E_{k\ell}^{\mu}
    =
    \delta_{\lambda\mu}\delta_{jk}E_{i\ell}^{\lambda},
    \qquad
    \bigl(E_{ij}^{\lambda}\bigr)^*=E_{ji}^{\lambda},
    
E_kUse in source · 13 passages

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  • Use in source · monograph_atlas.tex, line 29

    E_k · Positive measurement effect · It gives the outcome probability Tr(E_kρ).

    Exact mathematical passage
    E_k
E_{k\ell}^{\mu}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 251

    [Representation matrix units] Fix an irreducible unitary representation π_λ:G→ U(d_λ) and an orthonormal basis of its representation space. Define E_ij^λ = fracd_λabsG ∑_g∈ G [π_λ(g^-1)]_jiU(g). Then E_ij^λE_kℓ^μ = δ_λμδ_jkE_iℓ^λ, (E_ij^λ)^*=E_ji^λ, and P_λ=∑_i=1^d_λE_ii^λ.

    Exact mathematical passage
    
    E_{ij}^{\lambda}E_{k\ell}^{\mu}
    =
    \delta_{\lambda\mu}\delta_{jk}E_{i\ell}^{\lambda},
    \qquad
    \bigl(E_{ij}^{\lambda}\bigr)^*=E_{ji}^{\lambda},
    
E_rUse in source · 4 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 792

    Let P=P^*=P^2 project onto a code space C⊂ H, and let E_1,…,E_r be a finite family of complex error matrices. Neither a nonzero code nor channel normalization is assumed unless stated. The operators P E_a^*E_bP are the obstruction packets on the code. If they retain information about the logical state beyond one scalar multiple of P, the environment can distinguish logical states and exact correction is impossible.

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    E_1,\ldots,E_r
E_xUse in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 253

    vpage14A chart failure is not a singular fiberTHE RANGE BUNDLE IS CONSTRUCTED LOCALLYTraditional edition: Theorem II.6.7. Details of the range atlas: saved v0.6.0 supplement, pp. 2--4. The fiber of a projector field is the actual fixed subspace E_x={v:P(x)v=v}. To compare it with a nearby anchor fiber E_a, the completion proof constructs T_a(x)=P(x)P(a)+(I-P(x))(I-P(a)). It equals the identity at the anchor and intertwines the two projectors. Where it is invertible, its restriction provides loca…

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    E_x=\{v:P(x)v=v\}
E_zUse in source · 2 passages

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  • Use in source · Read passage · 03_supplement_04.tex, line 130

    very operator supported on the code, Pρ P=ρ, the central identity is R(V_aρ V_b^*)=δ_abρ. Consequently normalized mixtures satisfy R (∑_ap_aV_aρ V_a^*)=ρ when ∑_ap_a=1. The identity is algebraic and is proved for complex weights. Physical mixtures use the nonnegative real case. For a coherent error E_z=∑_a z_aV_a, the calculation of the cross terms yields R(E_zρ E_z^*)=(∑_a z_aoverlinez_a)ρ. Thus the same map also corrects normalized coherent superpositions. This construction supplies the recove…

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    E_z=\sum_a z_aV_a
E_z^*Use in source · 1 passage

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  • Use in source · Read passage · 03_supplement_04.tex, line 131

    identity is R(V_aρ V_b^*)=δ_abρ. Consequently normalized mixtures satisfy R (∑_ap_aV_aρ V_a^*)=ρ when ∑_ap_a=1. The identity is algebraic and is proved for complex weights. Physical mixtures use the nonnegative real case. For a coherent error E_z=∑_a z_aV_a, the calculation of the cross terms yields R(E_zρ E_z^*)=(∑_a z_aoverlinez_a)ρ. Thus the same map also corrects normalized coherent superpositions. This construction supplies the recovery stage used in the full Knill--Laflamme proof that foll…

    Exact mathematical passage
    
    \mathcal R(E_z\rho E_z^*)=\left(\sum_a z_a\overline{z_a}\right)\rho.
    
E_\ellUse in source · 6 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 1003

    At resolution ℓ, define Q_ℓ = ( A_ℓ, H_ℓ, D_ℓ, {P_ℓ,α}, E_ℓ, C_ℓ, Π_ℓ^phys, T_ℓ ). In order, the entries specify the observable algebra, Hilbert space, geometric or Dirac-type operator, packet projectors, embedding into the fine space, reconstruction onto the coarse space, physical constraint projector, and transfer operator. The maps have types E_ℓ: H_ℓ→ H_ℓ+1 and C_ℓ: H_ℓ+1→ H_ℓ. The left inverse relation C_ℓ E_ℓ=I alone does not imply C_ℓ=E_ℓ^* or make the embedding isometric.

    Exact mathematical passage
    
    \boxed{
    \mathfrak Q_\ell
    =
    \left(
    \cA_\ell,
    \cH_\ell,
    D_\ell,
    \{P_{\ell,\alpha}\},
    E_\ell,
    C_\ell,
    \Pi_\ell^{\mathrm{phys}},
    T_\ell
    \right).
    }
    
E_\ell^*Use in source · 1 passage

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  • Use in source · Read passage · 01_finite_core.tex, line 1019

    order, the entries specify the observable algebra, Hilbert space, geometric or Dirac-type operator, packet projectors, embedding into the fine space, reconstruction onto the coarse space, physical constraint projector, and transfer operator. The maps have types E_ℓ: H_ℓ→ H_ℓ+1 and C_ℓ: H_ℓ+1→ H_ℓ. The left inverse relation C_ℓ E_ℓ=I alone does not imply C_ℓ=E_ℓ^* or make the embedding isometric.

    Exact mathematical passage
    C_\ell=E_\ell^*
\mathrm{eff}Use in source · 7 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 907

    [Exact Feshbach resolvent] Assume that both zI_Q-H_QQ and zI-H are invertible. Define H_eff(z) = H_PP +H_PQ(z-H_QQ)^-1H_QP. Then P(z-H)^-1P = (z-H_eff(z))^-1 where the left side is restricted to P H, the right side is an inverse on that retained space, and both are written in the same orthonormal basis. Here z-H_QQ and z-H_eff abbreviate the appropriately sized scalar matrices minus the indicated blocks.

    Exact mathematical passage
    
    \boxed{
    H_{\mathrm{eff}}(z)
    =
    H_{PP}
    +H_{PQ}(z-H_{QQ})^{-1}H_{QP}.
    }
    
\operatorname{End}Use in source · 1 passage

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  • Use in source · Read passage · 01_finite_core.tex, line 573

    [Projected connection] Let M be a smooth finite-dimensional real manifold without boundary, let V be a finite-dimensional real normed vector space, and let P:M→End_ R(V) be smooth with P(x)^2=P(x). In the quantum application, V is the underlying real space of a finite complex Hilbert space and P is an orthogonal complex-linear projector.

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    P:M\to\operatorname{End}_{\bbR}(V)
\operatorname{End}_{\bbR}Use in source · 1 passage

Search aliases: End_bbR End_ R operatorname bbR operatorname mathbb

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  • Use in source · Read passage · 01_finite_core.tex, line 573

    [Projected connection] Let M be a smooth finite-dimensional real manifold without boundary, let V be a finite-dimensional real normed vector space, and let P:M→End_ R(V) be smooth with P(x)^2=P(x). In the quantum application, V is the underlying real space of a finite complex Hilbert space and P is an orthogonal complex-linear projector.

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    P:M\to\operatorname{End}_{\bbR}(V)
\mathrm{even}Use in source · 3 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 228

    For parity, S=Z^⊗ n, P_even=fracI+S2, P_odd=fracI-S2.

    Exact mathematical passage
    
    S=Z^{\otimes n},
    \qquad
    P_{\mathrm{even}}=\frac{I+S}{2},
    \qquad
    P_{\mathrm{odd}}=\frac{I-S}{2}.
    
\expUse in source · 9 passages

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  • Use in source · Read passage · 03_supplement_03.tex, line 93

    Constructed cyclic character projectors. Let N>0 and let S be a unitary complex matrix with S^N=I. The implementation uses the standard additive character of Z/N Z and proves its expression through a root of unity: ω=exp(2π i/N), χ(r)=ω^val(r). Here val(r) is the canonical representative in {0,…,N-1}. The representation is constructed as ρ(r)=S^val(r). Reduction of exponents modulo N is proved from S^N=I, giving ρ(r+s)=ρ(r)ρ(s) and ρ(0)=I. The final matrix theorem derives the representation law …

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    \omega=\exp(2\pi i/N),\qquad
    \chi(r)=\omega^{\operatorname{val}(r)}.
    
\mathrm{extra}Use in source · 2 passages

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  • Use in source · Read passage · 03_supplement_04.tex, line 109

    The recovery is not left undefined outside the syndrome subspaces. Its explicit Kraus operators are R_a=V_a^* together with R_extra=Q, giving R(ρ)=∑_aV_a^*ρ V_a+Qρ Q. They satisfy exact completeness: ∑_aR_a^*R_a+R_extra^*R_extra =∑_aV_aV_a^*+Q=S+Q=I. For finite complex matrices, trace preservation and complete positivity at every finite auxiliary dimension are proved for this actual map. The amplified map is identified with the Kraus family I_J⊗ R_a, including the complement term. Positivity is …

    Exact mathematical passage
    R_{\mathrm{extra}}=Q
F'Use in source · 2 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 443

    Set F(s)=e^isHPe^-isH. Differentiating the exponential gives F'(s)=i e^isH[H,P]e^-isH, F(0)=P. Unitary conjugation preserves the operator norm, so F'(s) = [H,P] . The mean-value estimate on the interval between 0 and t yields F(t)-P ≤ |t| [H,P] . Finally, e^itHQe^-itHP=(P-F(t))P and P ≤1. Left multiplication by e^itH preserves the norm and gives the desired inequality. This argument includes positive, negative and zero time.

    Exact mathematical passage
    
    F'(s)=i\,e^{isH}[H,P]e^{-isH},\qquad F(0)=P.
    
F^*Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 1295

    Exact correction of an error span means that one completely positive trace preserving recovery R satisfies R(Fρ F^*)=q_Fρ for every F in that span and every code-supported matrix ρ, with a nonnegative scalar q_F depending on F but not on the logical input. For every normalized channel with Kraus operators in the same span, the same recovery restores the code input with total scalar one. Individual unnormalized errors are not required to have unit recovery weight.

    Exact mathematical passage
    \Rcal(F\rho F^*)=q_F\rho
F_1Use in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 603

    0 · 0 · 0, PE_a^*E_bP=c_abP. The errors are redundant rather than three distinct syndromes. A real unitary change of error coordinates gives W=mat3/5 · 4/5 · 0 -4/5 · 3/5 · 0 0 · 0 · 1, WcW^*=diag(1,0,0), (F_1,F_2,F_3)=(P,0,0). xfiggram headNormalize only positive eigenvalues The positive branch has V_1=P as an isometry on the code, and syndrome support Q=P. No factor λ^-1/2 is formed on either zero branch: those branches vanish on the code. Treating them as extra recoverable packets would divid…

    Exact mathematical passage
    
    W=\mat{3/5&4/5&0\\-4/5&3/5&0\\0&0&1},
    \quad WcW^*=\diag(1,0,0),
    \quad(F_1,F_2,F_3)=(P,0,0).
    
F_2Use in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 603

    0 · 0 · 0, PE_a^*E_bP=c_abP. The errors are redundant rather than three distinct syndromes. A real unitary change of error coordinates gives W=mat3/5 · 4/5 · 0 -4/5 · 3/5 · 0 0 · 0 · 1, WcW^*=diag(1,0,0), (F_1,F_2,F_3)=(P,0,0). xfiggram headNormalize only positive eigenvalues The positive branch has V_1=P as an isometry on the code, and syndrome support Q=P. No factor λ^-1/2 is formed on either zero branch: those branches vanish on the code. Treating them as extra recoverable packets would divid…

    Exact mathematical passage
    
    W=\mat{3/5&4/5&0\\-4/5&3/5&0\\0&0&1},
    \quad WcW^*=\diag(1,0,0),
    \quad(F_1,F_2,F_3)=(P,0,0).
    
F_3Use in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 603

    0 · 0 · 0, PE_a^*E_bP=c_abP. The errors are redundant rather than three distinct syndromes. A real unitary change of error coordinates gives W=mat3/5 · 4/5 · 0 -4/5 · 3/5 · 0 0 · 0 · 1, WcW^*=diag(1,0,0), (F_1,F_2,F_3)=(P,0,0). xfiggram headNormalize only positive eigenvalues The positive branch has V_1=P as an isometry on the code, and syndrome support Q=P. No factor λ^-1/2 is formed on either zero branch: those branches vanish on the code. Treating them as extra recoverable packets would divid…

    Exact mathematical passage
    
    W=\mat{3/5&4/5&0\\-4/5&3/5&0\\0&0&1},
    \quad WcW^*=\diag(1,0,0),
    \quad(F_1,F_2,F_3)=(P,0,0).
    
F_aUse in source · 3 passages

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  • Use in source · Read passage · 03_supplement_05.tex, line 42

    From Gram data to an actual total recovery. Assume Csucceq0 and PE_a^*E_bP=C_abP. First restrict the error operators to the code, F_a=E_aP. The finite Hermitian spectral theorem supplies a unitary U such that U^*CU=diag(λ_r), λ_r≥0.

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    F_a=E_aP
F_a^*Use in source · 1 passage

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  • Use in source · Read passage · 03_supplement_05.tex, line 53

    Define the transformed errors by an actual finite sum, B_r=∑_a U_arF_a. The formal module proves the identities B_rP=B_r, B_r^*B_s=δ_rsλ_rP, ∑_rB_rρ B_r^*=∑_aF_aρ F_a^*. For ρ supported on the code, the restricted and unrestricted error sums are equal. Thus the unitary change of error coordinates preserves the actual channel on the code.

    Exact mathematical passage
    
    B_rP=B_r,\qquad B_r^*B_s=\delta_{rs}\lambda_rP,
    \qquad \sum_rB_r\rho B_r^*=\sum_aF_a\rho F_a^*.
    
f_{AB}^{\ \ C}Use in source · 2 passages

Search aliases: f_AB^ C

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  • Use in source · Read passage · 01_finite_core.tex, line 1198

    At one finite level, let widehat C_A be a finite family of matrix constraints, with fixed scalar structure coefficients, and let Π^phys be the orthogonal projector onto their exact common kernel. If the classical constraint algebra has structure coefficients f_AB^ C, define the anomaly operator A_AB = [widehat C_A,widehat C_B] -i∑_C f_AB^ Cwidehat C_C. Its physical packet is Π^phys A_ABΠ^phys. In this exact finite setting, widehat C_CΠ^phys=0 for every C. Associativity gives A_ABΠ^phys=0, Π^phys…

    Exact mathematical passage
    f_{AB}^{\ \ C}
f_cUse in source · 3 passages

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  • Use in source · Read passage · 03_supplement_01.tex, line 188

    A constraint diagnostic that vanishes automatically. Section 12 defines the physical projector using the exact common kernel of the constraints. In finite dimensions this gives C_aP=0 for every a. Absorb the factor i and any structure coefficient into f_c, and write A_ab=C_aC_b-C_bC_a-∑_cf_cC_c. [Exact common-kernel compression] If C_cP=0 for every c, then A_abP=0, P A_abP=0. No idempotence or adjoint property of P is needed for this implication. Associativity gives A_abP=C_a(C_bP)-C_b(C_aP)-∑_c…

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    f_c
F_jUse in source · 7 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 1323

    [Orthogonal syndrome construction] Assume the Knill Laflamme identities. Then the coefficient matrix c is positive semidefinite. Choose a unitary matrix W such that WcW^*=diag(λ_1,…,λ_r), λ_j≥0, and define F_j=∑_aoverlineW_jaE_a. For every j with λ_j>0, the operator V_j=λ_j^-1/2F_jP is an isometry from the code into H. Its range projector Q_j=V_jV_j^* is a syndrome packet, and the nonzero Q_j are pairwise orthogonal.

    Exact mathematical passage
    
    F_j=\sum_a\overline{W_{ja}}E_a.
    
F_j^*Use in source · 4 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 1343

    For z∈ C^r, let F_z=∑_az_aE_a. Then PF_z^*F_zP=(z^*cz)P≥0, so c≥0. The unitary change of error coordinates gives PF_j^*F_ℓ P = λ_jδ_jℓP. Thus V_j^*V_ℓ=δ_jℓP. Each V_j is an isometry on P H, and distinct ranges are orthogonal. Their range projectors are therefore pairwise orthogonal.

    Exact mathematical passage
    
    PF_j^*F_\ell P
    =
    \lambda_j\delta_{j\ell}P.
    
F_{P\circ f}Use in source · 1 passage

Search aliases: F_P∘ f circ

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  • Use in source · Read passage · 03_supplement_04.tex, line 86

    Tensor properties and the remaining global boundary. The coefficient is proved bilinear, alternating, and supported on the range on both sides. The chain rule proves the pullback identity F_P∘ f(x)(v,w)=F_P(f(x))(Df(x)v,Df(x)w). The main theorem has global regularity hypotheses on normed parameter spaces. The pullback identity alone does not supply localization, smooth local trivializations, or gluing. The final supplement constructs the global range bundle and proves that the local connections …

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    F_{P\circ f}(x)(v,w)=F_P(f(x))(Df(x)v,Df(x)w).
    
F_rUse in source · 6 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 843

    textitSufficiency. Diagonalize C=Udiag(λ_r)U^* with U unitary and λ_r≥0. Define compressed transformed errors F_r=∑_aU_arE_aP. Then F_rP=F_r and F_r^*F_s=λ_rδ_rsP. If λ_r=0, F_r^*F_r=0 forces F_r=0. For positive eigenvalues only, set V_r=F_r/sqrtλ_r. These satisfy V_rP=V_r, V_r^*V_s=δ_rsP. Let S=∑_λ_r>0V_rV_r^*. Orthogonality makes S an orthogonal projector. Use the recovery branches K_r=V_r^*, K_unused=I-S. They are complete on the whole ambient space because ∑_rK_r^*K_r+K_unused^*K_unused =S+(…

    Exact mathematical passage
    
    F_r=\sum_aU_{ar}E_aP.
    
F_r^*Use in source · 2 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 846

    textitSufficiency. Diagonalize C=Udiag(λ_r)U^* with U unitary and λ_r≥0. Define compressed transformed errors F_r=∑_aU_arE_aP. Then F_rP=F_r and F_r^*F_s=λ_rδ_rsP. If λ_r=0, F_r^*F_r=0 forces F_r=0. For positive eigenvalues only, set V_r=F_r/sqrtλ_r. These satisfy V_rP=V_r, V_r^*V_s=δ_rsP. Let S=∑_λ_r>0V_rV_r^*. Orthogonality makes S an orthogonal projector. Use the recovery branches K_r=V_r^*, K_unused=I-S. They are complete on the whole ambient space because ∑_rK_r^*K_r+K_unused^*K_unused =S+(…

    Exact mathematical passage
    F_r^*F_s=\lambda_r\delta_{rs}P
F_sUse in source · 1 passage

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  • Use in source · Read passage · 01_finite_core.tex, line 846

    textitSufficiency. Diagonalize C=Udiag(λ_r)U^* with U unitary and λ_r≥0. Define compressed transformed errors F_r=∑_aU_arE_aP. Then F_rP=F_r and F_r^*F_s=λ_rδ_rsP. If λ_r=0, F_r^*F_r=0 forces F_r=0. For positive eigenvalues only, set V_r=F_r/sqrtλ_r. These satisfy V_rP=V_r, V_r^*V_s=δ_rsP. Let S=∑_λ_r>0V_rV_r^*. Orthogonality makes S an orthogonal projector. Use the recovery branches K_r=V_r^*, K_unused=I-S. They are complete on the whole ambient space because ∑_rK_r^*K_r+K_unused^*K_unused =S+(…

    Exact mathematical passage
    F_r^*F_s=\lambda_r\delta_{rs}P
f_tUse in source · 1 passage

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  • Use in source · Read passage · 03_supplement_03.tex, line 143

    Connecting power series and spectral calculus. The shifted generator is proved Hermitian. The implementation then identifies the actual matrix exponential with continuous functional calculus: T_e(t)=f_t(H), f_t(x)=e^-t(x-e). The formal proof uses composition, scalar multiplication, subtraction, and the established agreement between the exponential in functional calculus and the exponential defined by a power series. Spectral mapping is consequently available for the operator that was actually de…

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    \boxed{T_e(t)=f_t(H),\qquad f_t(x)=e^{-t(x-e)}.}
    
F_zUse in source · 2 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 1338

    For z∈ C^r, let F_z=∑_az_aE_a. Then PF_z^*F_zP=(z^*cz)P≥0, so c≥0. The unitary change of error coordinates gives PF_j^*F_ℓ P = λ_jδ_jℓP. Thus V_j^*V_ℓ=δ_jℓP. Each V_j is an isometry on P H, and distinct ranges are orthogonal. Their range projectors are therefore pairwise orthogonal.

    Exact mathematical passage
    F_z=\sum_az_aE_a
F_z^*Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 1339

    For z∈ C^r, let F_z=∑_az_aE_a. Then PF_z^*F_zP=(z^*cz)P≥0, so c≥0. The unitary change of error coordinates gives PF_j^*F_ℓ P = λ_jδ_jℓP. Thus V_j^*V_ℓ=δ_jℓP. Each V_j is an isometry on P H, and distinct ranges are orthogonal. Their range projectors are therefore pairwise orthogonal.

    Exact mathematical passage
    
    PF_z^*F_zP=(z^*cz)P\geq0,
    
F_{\theta\phi}Use in source · 2 passages

Search aliases: F_θϕ theta phi

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  • Use in source · monograph_atlas.tex, line 277

    LOCH PROJECTOR CALCULATIONTraditional edition: Theorem II.6.7, Corollary II.6.8. On the unit sphere, set n=(sinθcosϕ,sinθsinϕ,cosθ) and P(θ,ϕ)=frac12(I+n·σ). This is a smooth rank-one orthogonal projector. The intrinsic curvature is the endomorphism-valued two-form P( d Pwedge d P)P. With the paper's scalar convention, its component is F_θϕ=- iTr (P[∂_θ P,∂_ϕ P]) =frac12sinθ. vfigbloch_curvature headA local frame gives the same answer Away from the south pole, use u_N=(cos(θ/2),e^ iϕsin(θ/2))^T.…

    Exact mathematical passage
    
    F_{\theta\phi}=-\ii\Tr\!\left(P[\partial_\theta P,\partial_\phi P]\right)
    =\frac12\sin\theta.
    
F_\ellUse in source · 1 passage

Search aliases: F_ℓ ell

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  • Use in source · Read passage · 02_strengthened.tex, line 1343

    For z∈ C^r, let F_z=∑_az_aE_a. Then PF_z^*F_zP=(z^*cz)P≥0, so c≥0. The unitary change of error coordinates gives PF_j^*F_ℓ P = λ_jδ_jℓP. Thus V_j^*V_ℓ=δ_jℓP. Each V_j is an isometry on P H, and distinct ranges are orthogonal. Their range projectors are therefore pairwise orthogonal.

    Exact mathematical passage
    
    PF_j^*F_\ell P
    =
    \lambda_j\delta_{j\ell}P.
    
\FcalUse in source · 5 passages

Search aliases: Fcal F mathcal

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  • Use in source · Read passage · 02_strengthened.tex, line 869

    [Nonabelian packet connection] The one form with matrix values A=V^* d V is skew adjoint. Under a frame change V'=VG, where G(x)∈ U(r), A' = G^* A G+G^* d G. Its curvature F= d A+ Awedge A satisfies F=V^*( d Pwedge d P)V.

    Exact mathematical passage
    
    \Fcal=\dd\Acal+\Acal\wedge\Acal
    
\Fcal_{\theta\phi}Use in source · 3 passages

Search aliases: Fcal_θϕ F_θϕ Fcal theta phi mathcal theta phi

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  • Use in source · Read passage · 02_strengthened.tex, line 901

    [Bloch sphere curvature] Let P(θ,ϕ) = frac12(I+ n(θ,ϕ)·σ), where n=(sinθcosϕ,sinθsinϕ,cosθ). With the convention F_θϕ =- iTr(P[∂_θ P,∂_ϕ P]), one has F_θϕ=frac12sinθ and frac12π ∫_0^2π∫_0^π F_θϕ dθ dϕ =1.

    Exact mathematical passage
    
    \Fcal_{\theta\phi}
    =-\ii\Tr\bigl(P[\partial_\theta P,\partial_\phi P]\bigr),
    
\mathrm{fine}Use in source · 1 passage

Search aliases: fine mathrm

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  • Use in source · Read passage · 01_finite_core.tex, line 239

    Fix N≥1. Suppose every factor a has a complete orthogonal family P^(a)_0,…,P^(a)_N-1. The fine tensor packets are P_ j^fine = P^(1)_j_1⊗⋯⊗ P^(m)_j_m.

    Exact mathematical passage
    
    P_{\mathbf j}^{\mathrm{fine}}
    =
    P^{(1)}_{j_1}\otimes\cdots\otimes P^{(m)}_{j_m}.
    
G^*Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 863

    [Nonabelian packet connection] The one form with matrix values A=V^* d V is skew adjoint. Under a frame change V'=VG, where G(x)∈ U(r), A' = G^* A G+G^* d G. Its curvature F= d A+ Awedge A satisfies F=V^*( d Pwedge d P)V.

    Exact mathematical passage
    
    \Acal'
    =
    G^*\Acal G+G^*\dd G.
    
g^{-1}Use in source · 3 passages

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  • Use in source · monograph_atlas.tex, line 534

    , not unproved continuum claims or a new theorem count. vpage29Nonabelian packets carry multiplicityA SIX-DIMENSIONAL REGULAR REPRESENTATIONTraditional edition: Theorem II.3.1, Theorem II.3.2. Let HH= C[S_3] have the six orthonormal basis vectors ket g, with left action U(h)ket g=kethg. The irreducible characters on the identity, transposition, and three-cycle classes are c|rrr|r · e · (12) · (123) · d_λ trivial · 1 · 1 · 1 · 1 sign · 1 · -1 · 1 · 1 standard · 2 · 0 · -1 · 2 P_λ=fracd_λ6∑_g∈ S_3…

    Exact mathematical passage
    
    \begin{array}{c|rrr|r}
     & e & (12)&(123)&d_\lambda\\\hline
    \text{trivial}&1&1&1&1\\
    \text{sign}&1&-1&1&1\\
    \text{standard}&2&0&-1&2
    \end{array}
    \qquad
    P_\lambda=\frac{d_\lambda}{6}\sum_{g\in S_3}\chi_\lambda(g^{-1})U(g).
    
g^2Use in source · 5 passages

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  • Use in source · monograph_atlas.tex, line 661

    The sign in the upper half plane comes from self-adjoint hidden data. It is not an entrywise sign condition on an arbitrary effective matrix. xfigstability headA stability estimate with a common spectral gap Compare (B,D)=(1,2) with (widetilde B,widetilde D)=(9/8,17/8) at z=3. Both hidden spectral distances are at least δ=3/4, and both couplings are bounded by g=9/8. Then |Σ-widetildeΣ|=|1-frac8156|=frac2556, frac2gδ|B-widetilde B| +fracg^2δ^2|D-widetilde D|=frac2132. The theorem bounds the diff…

    Exact mathematical passage
    
    |\Sigma-\widetilde\Sigma|=\left|1-\frac{81}{56}\right|=\frac{25}{56},
    \qquad
    \frac{2g}{\delta}|B-\widetilde B|
    +\frac{g^2}{\delta^2}|D-\widetilde D|=\frac{21}{32}.
    
g_{aa}Use in source · 1 passage

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  • Use in source · Read passage · 03_supplement_06.tex, line 50

    Smooth overlap maps and rank. The coordinate transition is g_ab(x)=A_b(x)B_a(x). It is smooth on U_a∩ U_b, agrees with the actual change between local homeomorphisms, and satisfies g_aa=I, g_bcg_ab=g_ac. A continuous linear equivalence between E_a and E_x also gives local constancy of fiber dimension. No single constant rank across disconnected components is assumed.

    Exact mathematical passage
    
    g_{aa}=I,\qquad g_{bc}g_{ab}=g_{ac}.
    
g_{ab}Use in source · 3 passages

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  • Use in source · Read passage · 03_supplement_06.tex, line 49

    Smooth overlap maps and rank. The coordinate transition is g_ab(x)=A_b(x)B_a(x). It is smooth on U_a∩ U_b, agrees with the actual change between local homeomorphisms, and satisfies g_aa=I, g_bcg_ab=g_ac. A continuous linear equivalence between E_a and E_x also gives local constancy of fiber dimension. No single constant rank across disconnected components is assumed.

    Exact mathematical passage
    g_{ab}(x)=A_b(x)B_a(x)
g_{ac}Use in source · 1 passage

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  • Use in source · Read passage · 03_supplement_06.tex, line 50

    Smooth overlap maps and rank. The coordinate transition is g_ab(x)=A_b(x)B_a(x). It is smooth on U_a∩ U_b, agrees with the actual change between local homeomorphisms, and satisfies g_aa=I, g_bcg_ab=g_ac. A continuous linear equivalence between E_a and E_x also gives local constancy of fiber dimension. No single constant rank across disconnected components is assumed.

    Exact mathematical passage
    
    g_{aa}=I,\qquad g_{bc}g_{ab}=g_{ac}.
    
g_{bc}Use in source · 1 passage

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  • Use in source · Read passage · 03_supplement_06.tex, line 50

    Smooth overlap maps and rank. The coordinate transition is g_ab(x)=A_b(x)B_a(x). It is smooth on U_a∩ U_b, agrees with the actual change between local homeomorphisms, and satisfies g_aa=I, g_bcg_ab=g_ac. A continuous linear equivalence between E_a and E_x also gives local constancy of fiber dimension. No single constant rank across disconnected components is assumed.

    Exact mathematical passage
    
    g_{aa}=I,\qquad g_{bc}g_{ab}=g_{ac}.
    
G_{jk}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 1876

    [Finite reflection positivity] For vectors v_1,…,v_m∈ H and nonnegative integers n_1,…,n_m, the matrix G_jk=ipv_jT^n_j+n_kv_k is positive semidefinite. Equivalently, ∑_j,koverlinec_jc_k ipv_jT^n_j+n_kv_k ≥0 for every c∈ C^m.

    Exact mathematical passage
    
    G_{jk}=\ip{v_j}{T^{n_j+n_k}v_k}
    
\GcalUse in source · 6 passages

Search aliases: Gcal G mathcal

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  • Use in source · Read passage · 02_strengthened.tex, line 1214

    [Finite Lindblad generator] A norm continuous semigroup of completely positive trace preserving maps on a finite matrix algebra, in the Schr odinger picture, has a generator of the form G(X) = - i[H,X] + ∑_r ( L_rXL_r^* - frac12L_r^*L_rX - frac12XL_r^*L_r ), where H=H^*. Conversely, every operator of this form generates a completely positive trace preserving semigroup [source reference].

    Exact mathematical passage
    
    \Gcal(X)
    =
    -\ii[H,X]
    +
    \sum_r
    \left(
    L_rXL_r^*
    -
    \frac12L_r^*L_rX
    -
    \frac12XL_r^*L_r
    \right),
    
hUse in source · 44 passages

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  • Use in source · monograph_atlas.tex, line 461

    vpage25Refine the grid while holding the mode fixedAN EXACT ERROR ENCLOSURE, NOT A FITTED SLOPETraditional edition: Theorem II.11.4. For the circle symbol, the continuum value is k^2 and the grid value is λ_k,h=frac4h^2sin^2 (frackh2), h≠0. For a fixed low mode, the paper bounds the error by 0≤ k^2-λ_k,h≤ k^4h^2/12. The spacing condition matters because the displayed expression divides by h^2. vfigdispersion headWhat is certified in the displayed table? Take k=1 and h=1/4,1/8,1/16. For x=h/2∈[0,…

    Exact mathematical passage
    
    \lambda_{k,h}=\frac4{h^2}\sin^2\!\left(\frac{kh}{2}\right),\qquad h\ne0.
    
H^{-1}Use in source · 1 passage

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  • Use in source · Read passage · monograph_examples.tex, line 10

    1 · 3) and retain its first coordinate. The eliminated block is invertible and the Schur complement of H is 2-1/3=5/3. Its inverse is 3/5, exactly the retained entry of H^-1. Inverting the compressed entry alone gives 1/2. The difference records the contribution of a path through the eliminated coordinate. Direct compression omits that contribution, while block inversion retains it. [H]centering includegraphics[width=.94textwidth]monograph_figures/exact_feshbach_compression.pdf captionThis ratio…

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    H^{-1}
h^{-2}Use in source · 1 passage

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  • Use in source · Read passage · 01_finite_core.tex, line 1143

    [Low-mode second-order bound] For every real k and every nonzero real h, define λ_k,h=4h^-2sin^2(kh/2). Then 0≤ k^2-λ_k,h ≤ frack^4h^212.

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    \lambda_{k,h}=4h^{-2}\sin^2(kh/2)
h^2Use in source · 20 passages

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  • Use in source · monograph_atlas.tex, line 461

    vpage25Refine the grid while holding the mode fixedAN EXACT ERROR ENCLOSURE, NOT A FITTED SLOPETraditional edition: Theorem II.11.4. For the circle symbol, the continuum value is k^2 and the grid value is λ_k,h=frac4h^2sin^2 (frackh2), h≠0. For a fixed low mode, the paper bounds the error by 0≤ k^2-λ_k,h≤ k^4h^2/12. The spacing condition matters because the displayed expression divides by h^2. vfigdispersion headWhat is certified in the displayed table? Take k=1 and h=1/4,1/8,1/16. For x=h/2∈[0,…

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    \lambda_{k,h}=\frac4{h^2}\sin^2\!\left(\frac{kh}{2}\right),\qquad h\ne0.
    
H_0Use in source · 3 passages

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  • Use in source · Read passage · 03_supplement_04.tex, line 40

    Checked consequences. Unitarity also gives the capped estimate Qexp(-itH)P ≤min{1, |t| [H,P] }. If H=H_0+V, both summands are self-adjoint, and [H_0,P]=0, then Qexp(-it(H_0+V))P ≤2|t| V . The latter uses [V,P] ≤2 V . Its constant is not claimed to be optimal. Exact commutation gives zero leakage. The work does not include unbounded generators or time-dependent Hamiltonians.

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    H=H_0+V
H_1Use in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 766

    vpage39Two routes to a bounded Hamiltonian limitEXACT EMBEDDINGS AND A SUMMABLE TAILTraditional edition: Theorem II.13.2, Theorem II.13.4, Corollary II.13.5. For the exact route, let HH_n= C^n with coordinate inclusions and H_n=diag(0,1,1/2,…,1/(n-1)), H_1=(0). The old energies are retained at every level, H_n+1R_n=R_nH_n, and normH_n≤1. On the Hilbert space of the direct limit ℓ^2( N_0), the diagonal sequence defines a bounded self-adjoint H_∞. Projectors onto even addresses also intertwine and…

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    H_n=\diag(0,1,1/2,\ldots,1/(n-1)),\qquad H_1=(0).
    
\mathcal H_AUse in source · 1 passage

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  • Use in source · Read passage · 03_supplement_03.tex, line 81

    Full support is expressed as surjectivity of the reduced matrix's linear map. Assuming d_A>0, the checked equivalence is O_A(ψ)= H_A⊗ H_B Longleftrightarrow Ranρ_B= H_B. Normalization of ψ is unnecessary for these dimension and support statements. The zero state has rank 0 because its decomposition needs no product terms.

    Exact mathematical passage
    
    \boxed{\mathcal O_A(\psi)=\mathcal H_A\otimes\mathcal H_B
    \quad\Longleftrightarrow\quad \Ran\rho_B=\mathcal H_B.}
    
\mathcal H_BUse in source · 1 passage

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  • Use in source · Read passage · 03_supplement_03.tex, line 81

    Full support is expressed as surjectivity of the reduced matrix's linear map. Assuming d_A>0, the checked equivalence is O_A(ψ)= H_A⊗ H_B Longleftrightarrow Ranρ_B= H_B. Normalization of ψ is unnecessary for these dimension and support statements. The zero state has rank 0 because its decomposition needs no product terms.

    Exact mathematical passage
    
    \boxed{\mathcal O_A(\psi)=\mathcal H_A\otimes\mathcal H_B
    \quad\Longleftrightarrow\quad \Ran\rho_B=\mathcal H_B.}
    
H_{\mathrm{eff}}Use in source · 7 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 907

    [Exact Feshbach resolvent] Assume that both zI_Q-H_QQ and zI-H are invertible. Define H_eff(z) = H_PP +H_PQ(z-H_QQ)^-1H_QP. Then P(z-H)^-1P = (z-H_eff(z))^-1 where the left side is restricted to P H, the right side is an inverse on that retained space, and both are written in the same orthonormal basis. Here z-H_QQ and z-H_eff abbreviate the appropriately sized scalar matrices minus the indicated blocks.

    Exact mathematical passage
    
    \boxed{
    H_{\mathrm{eff}}(z)
    =
    H_{PP}
    +H_{PQ}(z-H_{QQ})^{-1}H_{QP}.
    }
    
H_{\mathrm{eff}}^*Use in source · 1 passage

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  • Use in source · Read passage · 03_supplement_02.tex, line 110

    The explicitly defined coordinate curve y(s)=U(s)^*ψ(s) is differentiable at t, with dot y=dot U^*ψ(t)+U(t)^*dotψ. It satisfies idot y=H_effy(t), H_eff=U(t)^*HU(t)-iU(t)^*dot U. The connection term -iU(t)^*dot U is Hermitian. If H^*=H, then H_eff^*=H_eff.

    Exact mathematical passage
    H_{\mathrm{eff}}^*=H_{\mathrm{eff}}
H_{\mathrm{even}}Use in source · 2 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 395

    For two qubits and real parameters J,h, consider H = JX⊗ X +h(Z⊗ I+I⊗ Z). In the ordered even basis {ket00,ket11} and odd basis {ket01,ket10}, H_even = 2h · J J · -2h , H_odd = 0 · J J · 0 . Therefore Spec H_even ={±sqrt4h^2+J^2}, Spec H_odd={± J}.

    Exact mathematical passage
    
    H_{\mathrm{even}}
    =
    \begin{pmatrix}
    2h&J\\
    J&-2h
    \end{pmatrix},
    \qquad
    H_{\mathrm{odd}}
    =
    \begin{pmatrix}
    0&J\\
    J&0
    \end{pmatrix}.
    
H_nUse in source · 24 passages

Search aliases: H_n

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  • Use in source · monograph_atlas.tex, line 766

    vpage39Two routes to a bounded Hamiltonian limitEXACT EMBEDDINGS AND A SUMMABLE TAILTraditional edition: Theorem II.13.2, Theorem II.13.4, Corollary II.13.5. For the exact route, let HH_n= C^n with coordinate inclusions and H_n=diag(0,1,1/2,…,1/(n-1)), H_1=(0). The old energies are retained at every level, H_n+1R_n=R_nH_n, and normH_n≤1. On the Hilbert space of the direct limit ℓ^2( N_0), the diagonal sequence defines a bounded self-adjoint H_∞. Projectors onto even addresses also intertwine and…

    Exact mathematical passage
    
    H_n=\diag(0,1,1/2,\ldots,1/(n-1)),\qquad H_1=(0).
    
H_{n+1}Use in source · 3 passages

Search aliases: H_n+1

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  • Use in source · monograph_atlas.tex, line 769

    vpage39Two routes to a bounded Hamiltonian limitEXACT EMBEDDINGS AND A SUMMABLE TAILTraditional edition: Theorem II.13.2, Theorem II.13.4, Corollary II.13.5. For the exact route, let HH_n= C^n with coordinate inclusions and H_n=diag(0,1,1/2,…,1/(n-1)), H_1=(0). The old energies are retained at every level, H_n+1R_n=R_nH_n, and normH_n≤1. On the Hilbert space of the direct limit ℓ^2( N_0), the diagonal sequence defines a bounded self-adjoint H_∞. Projectors onto even addresses also intertwine and…

    Exact mathematical passage
    H_{n+1}R_n=R_nH_n
H_{n+1,n}Use in source · 1 passage

Search aliases: H_n+1,n

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  • Use in source · Read passage · 01_finite_core.tex, line 1079

    The paper tests a controlled volume-state model H_nn=2κ+V(n), H_n,n+1=H_n+1,n=-κ, with κ>0 and a real confining potential. This is a finite transfer-matrix test only. Operator positivity alone is not reflection positivity of a Euclidean field measure. It is not derived from a gravitational path integral and is not evidence for a unique microscopic spacetime dynamics.

    Exact mathematical passage
    
    H_{nn}=2\kappa+V(n),
    \qquad
    H_{n,n+1}=H_{n+1,n}=-\kappa,
    
H_{n,n+1}Use in source · 1 passage

Search aliases: H_n,n+1

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  • Use in source · Read passage · 01_finite_core.tex, line 1079

    The paper tests a controlled volume-state model H_nn=2κ+V(n), H_n,n+1=H_n+1,n=-κ, with κ>0 and a real confining potential. This is a finite transfer-matrix test only. Operator positivity alone is not reflection positivity of a Euclidean field measure. It is not derived from a gravitational path integral and is not evidence for a unique microscopic spacetime dynamics.

    Exact mathematical passage
    
    H_{nn}=2\kappa+V(n),
    \qquad
    H_{n,n+1}=H_{n+1,n}=-\kappa,
    
H_{nn}Use in source · 1 passage

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  • Use in source · Read passage · 01_finite_core.tex, line 1079

    The paper tests a controlled volume-state model H_nn=2κ+V(n), H_n,n+1=H_n+1,n=-κ, with κ>0 and a real confining potential. This is a finite transfer-matrix test only. Operator positivity alone is not reflection positivity of a Euclidean field measure. It is not derived from a gravitational path integral and is not evidence for a unique microscopic spacetime dynamics.

    Exact mathematical passage
    
    H_{nn}=2\kappa+V(n),
    \qquad
    H_{n,n+1}=H_{n+1,n}=-\kappa,
    
H_{\mathrm{odd}}Use in source · 2 passages

Search aliases: H_odd mathrm

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  • Use in source · Read passage · 01_finite_core.tex, line 395

    For two qubits and real parameters J,h, consider H = JX⊗ X +h(Z⊗ I+I⊗ Z). In the ordered even basis {ket00,ket11} and odd basis {ket01,ket10}, H_even = 2h · J J · -2h , H_odd = 0 · J J · 0 . Therefore Spec H_even ={±sqrt4h^2+J^2}, Spec H_odd={± J}.

    Exact mathematical passage
    
    H_{\mathrm{even}}
    =
    \begin{pmatrix}
    2h&J\\
    J&-2h
    \end{pmatrix},
    \qquad
    H_{\mathrm{odd}}
    =
    \begin{pmatrix}
    0&J\\
    J&0
    \end{pmatrix}.
    
H_{PP}Use in source · 6 passages

Search aliases: H_PP

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  • Use in source · monograph_atlas.tex, line 389

    1 · 2 and retain its first coordinate. The eliminated block is H_QQ=2. Whenever z-2 and the full zI-H are invertible, H_rm eff(z)=frac1z-2, [(zI-H)^-1]_00 =frac1z-1/(z-2)=fracz-2z^2-2z-1. This is the corrected hypothesis set recorded in the formal release. vfigfeshbach At z=3, the exact retained resolvent is 1/2. Bare truncation uses only H_PP=0 and gives 1/3, an error of 1/6. The omitted coupling has changed the response even though the retained diagonal entry did not change. headA pole can bel…

    Exact mathematical passage
    H_{PP}=0
H_{PQ}Use in source · 7 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 897

    Let P be a retained packet projector and Q=I-P. In packet coordinates, H= H_PP · H_PQ H_QP · H_QQ .

    Exact mathematical passage
    
    H=
    \begin{pmatrix}
    H_{PP}&H_{PQ}\\
    H_{QP}&H_{QQ}
    \end{pmatrix}.
    
H_{QP}Use in source · 7 passages

Search aliases: H_QP

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  • Use in source · Read passage · 01_finite_core.tex, line 897

    Let P be a retained packet projector and Q=I-P. In packet coordinates, H= H_PP · H_PQ H_QP · H_QQ .

    Exact mathematical passage
    
    H=
    \begin{pmatrix}
    H_{PP}&H_{PQ}\\
    H_{QP}&H_{QQ}
    \end{pmatrix}.
    
H_{QQ}Use in source · 12 passages

Search aliases: H_QQ

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  • Use in source · monograph_atlas.tex, line 381

    1 · 2 and retain its first coordinate. The eliminated block is H_QQ=2. Whenever z-2 and the full zI-H are invertible, H_rm eff(z)=frac1z-2, [(zI-H)^-1]_00 =frac1z-1/(z-2)=fracz-2z^2-2z-1. This is the corrected hypothesis set recorded in the formal release. vfigfeshbach At z=3, the exact retained resolvent is 1/2. Bare truncation uses only H_PP=0 and gives 1/3, an error of 1/6. The omitted coupling has changed the response even though the retained diagonal entry did not change. headA pole can bel…

    Exact mathematical passage
    H_{QQ}=2
H_{\rm d}Use in source · 4 passages

Search aliases: H_rm d rm

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  • Use in source · Read passage · 02_strengthened.tex, line 576

    Let H_rm d=PHP+QHQ, H_rm o=PHQ+QHP. The propagator generated by H_rm d preserves P H and Q H. Duhamel's formula relative to H_rm d gives Q e^- i tHP = - i ∫_0^t Q e^- i(t-s)HH_rm o e^- i sH_rm dP d s. Since H_rm oP=QHP and both propagators are unitary, the norm is at most abstnormQHP. Use [source reference] for the last equality.

    Exact mathematical passage
    
    H_{\rm d}=PHP+QHQ,
    \qquad
    H_{\rm o}=PHQ+QHP.
    
H_{\rm eff}Use in source · 1 passage

Search aliases: H_rm eff rm

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  • Use in source · monograph_atlas.tex, line 382

    1 · 2 and retain its first coordinate. The eliminated block is H_QQ=2. Whenever z-2 and the full zI-H are invertible, H_rm eff(z)=frac1z-2, [(zI-H)^-1]_00 =frac1z-1/(z-2)=fracz-2z^2-2z-1. This is the corrected hypothesis set recorded in the formal release. vfigfeshbach At z=3, the exact retained resolvent is 1/2. Bare truncation uses only H_PP=0 and gives 1/3, an error of 1/6. The omitted coupling has changed the response even though the retained diagonal entry did not change. headA pole can bel…

    Exact mathematical passage
    
    H_{\rm eff}(z)=\frac1{z-2},\qquad
    \bigl[(zI-H)^{-1}\bigr]_{00}
    =\frac1{z-1/(z-2)}=\frac{z-2}{z^2-2z-1}.
    
H_{\rm even}Use in source · 1 passage

Search aliases: H_rm even rm

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  • Use in source · monograph_atlas.tex, line 175

    etry reveals blocks, not approximationsONE HAMILTONIAN IN TWO ORDERSTraditional edition: Theorem II.5.1. Take the exact rational Hamiltonian H=X⊗ X+frac38(Z⊗ I+I⊗ Z). It commutes with total parity Z⊗ Z. Reordering the computational basis into even addresses (00,11) and odd addresses (01,10) displays the invariant subspaces explicitly. vfighamiltonian H_rm even=mat3/4 · 1 1 · -3/4, H_rm odd=mat0 · 1 1 · 0. The even block squares to (25/16)I, so its eigenvalues are ±5/4. The odd block squares to I…

    Exact mathematical passage
    
    H_{\rm even}=\mat{3/4&1\\1&-3/4},\qquad
    H_{\rm odd}=\mat{0&1\\1&0}.
    
H_{\rm frame}Use in source · 1 passage

Search aliases: H_rm frame rm

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  • Use in source · monograph_atlas.tex, line 218

    1 · 0. Since U^*dot U=J, the coordinate Hamiltonian is H_rm frame=- i J=mat0 · i - i · 0, idot y=H_rm framey. This matrix is Hermitian. Omitting it would predict a constant y, contradicting the displayed coordinates. In this example the norm of the omitted time derivative is exactly one, so the failure is not a small numerical residual.

    Exact mathematical passage
    
    H_{\rm frame}=-\ii J=\mat{0&\ii\\-\ii&0},
    \qquad \ii\dot y=H_{\rm frame}y.
    
H_{\rm Had}Use in source · 4 passages

Search aliases: H_rm Had rm

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  • Use in source · monograph_atlas.tex, line 40

    A Hamiltonian and a Hadamard gate are both traditionally denoted H. Where both appear, the gate is H_rm Had and the Hamiltonian keeps the letter H. Numerical labels on a drawing are coordinates or exact example values, not observations of a physical device. takeawayCheck the type before interpreting the picture. An idempotent projector, a density matrix, and a channel matrix have different defining equations.

    Exact mathematical passage
    H_{\rm Had}
H_{\rm mov}Use in source · 5 passages

Search aliases: H_rm mov rm

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  • Use in source · Read passage · 02_strengthened.tex, line 704

    [Moving frame Hamiltonian] Let U(t) solve idot U(t)=H(t)U(t), U(0)=I, where H(t)=H(t)^* is continuous on the compact time interval under consideration. Set V(t)=W(t)^*U(t). Then idot V(t)=H_rm mov(t)V(t), where H_rm mov(t) = W(t)^*H(t)W(t)- i W(t)^*dot W(t) = W(t)^*(H(t)- i K(t))W(t). The moving frame Hamiltonian is self adjoint.

    Exact mathematical passage
    
    \ii\dot V(t)=H_{\rm mov}(t)V(t),
    
H_{\rm o}Use in source · 3 passages

Search aliases: H_rm o rm

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  • Use in source · Read passage · 02_strengthened.tex, line 576

    Let H_rm d=PHP+QHQ, H_rm o=PHQ+QHP. The propagator generated by H_rm d preserves P H and Q H. Duhamel's formula relative to H_rm d gives Q e^- i tHP = - i ∫_0^t Q e^- i(t-s)HH_rm o e^- i sH_rm dP d s. Since H_rm oP=QHP and both propagators are unitary, the norm is at most abstnormQHP. Use [source reference] for the last equality.

    Exact mathematical passage
    
    H_{\rm d}=PHP+QHQ,
    \qquad
    H_{\rm o}=PHQ+QHP.
    
H_{\rm odd}Use in source · 1 passage

Search aliases: H_rm odd rm

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  • Use in source · monograph_atlas.tex, line 175

    etry reveals blocks, not approximationsONE HAMILTONIAN IN TWO ORDERSTraditional edition: Theorem II.5.1. Take the exact rational Hamiltonian H=X⊗ X+frac38(Z⊗ I+I⊗ Z). It commutes with total parity Z⊗ Z. Reordering the computational basis into even addresses (00,11) and odd addresses (01,10) displays the invariant subspaces explicitly. vfighamiltonian H_rm even=mat3/4 · 1 1 · -3/4, H_rm odd=mat0 · 1 1 · 0. The even block squares to (25/16)I, so its eigenvalues are ±5/4. The odd block squares to I…

    Exact mathematical passage
    
    H_{\rm even}=\mat{3/4&1\\1&-3/4},\qquad
    H_{\rm odd}=\mat{0&1\\1&0}.
    
H_TUse in source · 3 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 1860

    [Hamiltonian reconstruction from transfer] Let T be positive definite, self adjoint, and contractive. Then H_T=-a^-1log T is a nonnegative self adjoint operator and T^n= e^-naH_T. It is the unique nonnegative self adjoint operator with T= e^-aH_T.

    Exact mathematical passage
    
    H_T=-a^{-1}\log T
    
H_{\ell+1}Use in source · 1 passage

Search aliases: H_ℓ+1 ell

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  • Use in source · Read passage · 02_strengthened.tex, line 2368

    [Bounded Hamiltonian direct limit] Assume H_ℓ+1R_ℓ=R_ℓ H_ℓ and sup_ℓnormH_ℓ<∞. Then there is a unique bounded self adjoint operator H_∞ on H_∞ such that H_∞ι_ℓ=ι_ℓ H_ℓ for every ℓ. It satisfies e^- i tH_∞ι_ℓ = ι_ℓ e^- i tH_ℓ and e^-tH_∞ι_ℓ = ι_ℓ e^-tH_ℓ when the Hamiltonians are nonnegative.

    Exact mathematical passage
    
    H_{\ell+1}R_\ell=R_\ell H_\ell
    
H_\inftyUse in source · 7 passages

Search aliases: H_∞ infty

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  • Use in source · monograph_atlas.tex, line 769

    ditional edition: Theorem II.13.2, Theorem II.13.4, Corollary II.13.5. For the exact route, let HH_n= C^n with coordinate inclusions and H_n=diag(0,1,1/2,…,1/(n-1)), H_1=(0). The old energies are retained at every level, H_n+1R_n=R_nH_n, and normH_n≤1. On the Hilbert space of the direct limit ℓ^2( N_0), the diagonal sequence defines a bounded self-adjoint H_∞. Projectors onto even addresses also intertwine and give a fixed complete system of two packets in the limit. xfigtower_tail headCompatibi…

    Exact mathematical passage
    H_\infty
\Hcal_AUse in source · 3 passages

Search aliases: Hcal_A H_A Hcal mathcal

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  • Use in source · Read passage · 02_strengthened.tex, line 154

    [Local orbit and Schmidt rank] Let ψ∈ H_A⊗ H_B, let d_A=dim H_A≥1, and let r be the Schmidt rank of ψ. Then dimspan{(A⊗ I_B)ψ:A∈End( H_A)} = d_A r. Local operators on A generate the whole bipartite Hilbert space exactly when the reduced state on B has full support.

    Exact mathematical passage
    \psi\in\Hcal_A\otimes\Hcal_B
\Hcal_BUse in source · 1 passage

Search aliases: Hcal_B H_B Hcal mathcal

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  • Use in source · Read passage · 02_strengthened.tex, line 154

    [Local orbit and Schmidt rank] Let ψ∈ H_A⊗ H_B, let d_A=dim H_A≥1, and let r be the Schmidt rank of ψ. Then dimspan{(A⊗ I_B)ψ:A∈End( H_A)} = d_A r. Local operators on A generate the whole bipartite Hilbert space exactly when the reduced state on B has full support.

    Exact mathematical passage
    \psi\in\Hcal_A\otimes\Hcal_B
\Hcal_{\phys}Use in source · 4 passages

Search aliases: Hcal_phys H_phys Hcal phys mathcal mathrm

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  • Use in source · Read passage · 02_strengthened.tex, line 2216

    [Physical compression is not a closure test] Let H_phys=⋂_aKer C_a and let P_phys be its orthogonal projector. Then P_phys[C_a,C_b]P_phys=0 for every pair a,b, whether or not the constraint span closes.

    Exact mathematical passage
    
    \Hcal_{\phys}=\bigcap_a\Ker C_a
    
\Hcal_XUse in source · 2 passages

Search aliases: Hcal_X H_X Hcal mathcal

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  • Use in source · Read passage · 02_strengthened.tex, line 1042

    Let Φ:End( H_X)→End( H_Y) be linear. Choose packet systems (P_a) on H_X and (Q_c) on H_Y. Define Φ_cd,ab = Q_cdΦ P_ab.

    Exact mathematical passage
    \Phi:\End(\Hcal_X)\to\End(\Hcal_Y)
\Hcal_YUse in source · 3 passages

Search aliases: Hcal_Y H_Y Hcal mathcal

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  • Use in source · Read passage · 02_strengthened.tex, line 1042

    Let Φ:End( H_X)→End( H_Y) be linear. Choose packet systems (P_a) on H_X and (Q_c) on H_Y. Define Φ_cd,ab = Q_cdΦ P_ab.

    Exact mathematical passage
    \Phi:\End(\Hcal_X)\to\End(\Hcal_Y)
\Hcal_ZUse in source · 1 passage

Search aliases: Hcal_Z H_Z Hcal mathcal

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  • Use in source · Read passage · 02_strengthened.tex, line 1054

    [Exact channel block calculus] Every linear map has the exact reconstruction Φ=∑_a,b,c,dΦ_cd,ab. If Ψ:End( H_Y)→End( H_Z), then (ΨΦ)_ef,ab = ∑_c,d Ψ_ef,cdΦ_cd,ab.

    Exact mathematical passage
    \Psi:\End(\Hcal_Y)\to\End(\Hcal_Z)
\Hcal_\inftyUse in source · 4 passages

Search aliases: Hcal_∞ H_∞ Hcal infty mathcal infty

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  • Use in source · Read passage · 02_strengthened.tex, line 2360

    Let H_∞ be the Hilbert direct limit of the isometric system, and let ι_ℓ: H_ℓ⟶ H_∞ be the canonical isometries.

    Exact mathematical passage
    \Hcal_\infty
\HHUse in source · 7 passages

Search aliases: HH

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  • Use in source · monograph_atlas.tex, line 25

    midrule HH,ψ · Hilbert space and state vector · They specify the space of addresses and its coherent amplitudes.

    Exact mathematical passage
    \HH,\psi
\HH_nUse in source · 1 passage

Search aliases: HH_n HH

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  • Use in source · monograph_atlas.tex, line 765

    vpage39Two routes to a bounded Hamiltonian limitEXACT EMBEDDINGS AND A SUMMABLE TAILTraditional edition: Theorem II.13.2, Theorem II.13.4, Corollary II.13.5. For the exact route, let HH_n= C^n with coordinate inclusions and H_n=diag(0,1,1/2,…,1/(n-1)), H_1=(0). The old energies are retained at every level, H_n+1R_n=R_nH_n, and normH_n≤1. On the Hilbert space of the direct limit ℓ^2( N_0), the diagonal sequence defines a bounded self-adjoint H_∞. Projectors onto even addresses also intertwine and…

    Exact mathematical passage
    \HH_n=\CC^n
\hlineUse in source · 2 passages

Search aliases: hline

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  • Use in source · monograph_atlas.tex, line 534

    , not unproved continuum claims or a new theorem count. vpage29Nonabelian packets carry multiplicityA SIX-DIMENSIONAL REGULAR REPRESENTATIONTraditional edition: Theorem II.3.1, Theorem II.3.2. Let HH= C[S_3] have the six orthonormal basis vectors ket g, with left action U(h)ket g=kethg. The irreducible characters on the identity, transposition, and three-cycle classes are c|rrr|r · e · (12) · (123) · d_λ trivial · 1 · 1 · 1 · 1 sign · 1 · -1 · 1 · 1 standard · 2 · 0 · -1 · 2 P_λ=fracd_λ6∑_g∈ S_3…

    Exact mathematical passage
    
    \begin{array}{c|rrr|r}
     & e & (12)&(123)&d_\lambda\\\hline
    \text{trivial}&1&1&1&1\\
    \text{sign}&1&-1&1&1\\
    \text{standard}&2&0&-1&2
    \end{array}
    \qquad
    P_\lambda=\frac{d_\lambda}{6}\sum_{g\in S_3}\chi_\lambda(g^{-1})U(g).
    
\HSUse in source · 4 passages

Search aliases: HS mathrm

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  • Use in source · Read passage · 02_strengthened.tex, line 939

    Density matrices and observables carry both an input packet and an output packet. Equip End( H) with the Hilbert Schmidt inner product ipXY_HS=Tr(X^*Y).

    Exact mathematical passage
    
    \ip{X}{Y}_{\HS}=\Tr(X^*Y).
    
I^*Use in source · 1 passage

Search aliases: I^*

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  • Use in source · monograph_atlas.tex, line 370

    main inside the original code, so the previous syndrome partition reports no bit flip. frac3ket000+4ket1115 ⟼ frac3ket000-4ket1115. The populations are unchanged, but the relative phase is not. vfiglogical_error Let V be the code isometry with columns ket000,ket111. For the proposed error family {I,Z_1}, its off-diagonal error compression is V^*I^*Z_1V=mat1 · 0 0 · -1. This matrix is not cI for any scalar c. Thus the Knill--Laflamme condition fails for that family. Its trace is zero even though …

    Exact mathematical passage
    
    V^*I^*Z_1V=\mat{1&0\\0&-1}.
    
I_3Use in source · 3 passages

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  • Use in source · monograph_atlas.tex, line 74

    vpage5Why one seed is not always enoughAN EXACT MULTIPLICITY LOWER BOUNDTraditional edition: Theorem II.2.3. Consider M_2( C)⊗ I_3 acting on C^2⊗ C^3. A seed is a 2×3 coefficient matrix. Its two rows span at most two directions in the three-dimensional multiplicity factor. Therefore no single seed is cyclic for this algebra. C_1=mat1 · 0 · 0

    Exact mathematical passage
    M_2(\CC)\otimes I_3
I_6Use in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 544

    standard · 2 · 0 · -1 · 2 P_λ=fracd_λ6∑_g∈ S_3χ_λ(g^-1)U(g). All matrices in this example are rational. Multiplying them gives self-adjoint idempotents of ranks 1,1,4, with pairwise zero products and sum I_6. xfigs3 headThe standard packet has dimension four The standard representation occurs twice in the regular representation. Its isotypic component therefore has dimension 2·2=4: one factor carries the two-dimensional irreducible action and the other records multiplicity. A character projector…

    Exact mathematical passage
    I_6
I_BUse in source · 4 passages

Search aliases: I_B

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  • Use in source · Read passage · 01_finite_core.tex, line 138

    [Local orbit and Schmidt rank] Let ψ∈ H_A⊗ H_B, with dim H_A=d_A≥1, and let r be its Schmidt rank. The reduced positive operator on B is ρ_B=Tr_A(ketψbraψ). Normalization of ψ does not affect its support. Then dimspan{(A⊗ I_B)ψ:A∈ M_d_A( C)} =d_A r. In particular, local operators on A generate the complete bipartite Hilbert space exactly when the reduced state on B has full support.

    Exact mathematical passage
    
    \boxed{
    \dim\operatorname{span}\{(A\otimes I_B)\psi:A\in M_{d_A}(\bbC)\}
    =d_A r.
    }
    
I_{\Hcal}Use in source · 1 passage

Search aliases: I_Hcal I_ H Hcal mathcal

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  • Use in source · Read passage · 02_strengthened.tex, line 215

    [Finite group isotypic projectors] The operators P_λ = fracd_λabsG ∑_g∈ G overlineχ_λ(g)U(g) are orthogonal projectors. They satisfy P_λ P_μ=δ_λμP_λ, ∑_λ∈widehat GP_λ=I_ H. The range of P_λ is the λ isotypic component of H.

    Exact mathematical passage
    
    P_\lambda P_\mu=\delta_{\lambda\mu}P_\lambda,
    \qquad
    \sum_{\lambda\in\widehat G}P_\lambda=I_{\Hcal}.
    
I_JUse in source · 2 passages

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  • Use in source · Read passage · 03_supplement_02.tex, line 211

    To prove complete positivity rather than positivity alone, let J be an arbitrary finite auxiliary index set. For a matrix X indexed by J× n, define its blockwise amplification by [Φ^(J)(X)]_(i,u),(j,v) =Φ(X_(i,·),(j,·))_u,v. The explicit index calculation proves the identity Φ^(J)(X)=∑_a (I_J⊗ K_a)X(I_J⊗ K_a)^*. The displayed identity identifies the defined amplification with tensoring by the identity, which is the operation needed for complete positivity. Every summand on the right is positive …

    Exact mathematical passage
    
     \boxed{\quad
     \Phi^{(J)}(X)=\sum_a (I_J\otimes K_a)X(I_J\otimes K_a)^*.
     \quad}
    
I_mUse in source · 7 passages

Search aliases: I_m

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  • Use in source · monograph_atlas.tex, line 82

    0 · 0 · 0. These two matrices provide a complete set of row directions. Their individual orbit dimensions are four and two, and together those spans fill the six-dimensional state space. vfigseed_rank headFrom the example to the finite formula For a block M_d( C)⊗ I_m, k seed matrices contribute at most kd independent multiplicity directions. Hence k≥lceil m/drceil. Partitioning a multiplicity basis into groups of size at most d attains this bound. For a direct sum of such blocks, the worst bloc…

    Exact mathematical passage
    M_d(\CC)\otimes I_m
I_{m_r}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 104

    Let A ≅ ⊕_r=1^s (M_d_r( C)⊗ I_m_r) act on H ≅ ⊕_r=1^s ( C^d_r⊗ C^m_r). Assume d_r,m_r≥1 for each displayed block. For an empty block family, the seed rank and the displayed finite supremum are defined as zero. A vector in one block is identified with a d_r by m_r coefficient matrix.

    Exact mathematical passage
    
    \Acal
    \cong
    \bigoplus_{r=1}^{s}
    \bigl(M_{d_r}(\CC)\otimes I_{m_r}\bigr)
    
I_{M_\mu}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 225

    Complete reducibility gives a unitary decomposition H ≅ ⊕_μ∈widehat G V_μ⊗ M_μ, U(g) ≅ ⊕_μ π_μ(g)⊗ I_M_μ. On the μ summand, the displayed average is central in the irreducible representation π_μ, so it is a scalar by Schur's lemma. Taking its trace and applying character orthogonality shows that the scalar is one when μ=λ and zero otherwise. The asserted identities follow on the direct sum.

    Exact mathematical passage
    
    \Hcal
    \cong
    \bigoplus_{\mu\in\widehat G}
    V_\mu\otimes M_\mu,
    \qquad
    U(g)
    \cong
    \bigoplus_\mu
    \pi_\mu(g)\otimes I_{M_\mu}.
    
I_PUse in source · 3 passages

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  • Use in source · Read passage · 03_supplement_01.tex, line 101

    Corrected Feshbach resolvent. Write a finite complex matrix in retained and eliminated coordinates: H=A · B{ C · D, zI-H=zI_P-A · -B -C · zI_Q-D. Set D_z=zI_Q-D, S_z=zI_P-A-BD_z^-1C. The effective Hamiltonian is H_eff(z)=A+BD_z^-1C, so S_z=zI_P-H_eff(z).

    Exact mathematical passage
    
    H=\begin{pmatrix}A&B\\C&D\end{pmatrix},\qquad
    zI-H=\begin{pmatrix}zI_P-A&-B\\-C&zI_Q-D\end{pmatrix}.
    
I_QUse in source · 3 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 906

    [Exact Feshbach resolvent] Assume that both zI_Q-H_QQ and zI-H are invertible. Define H_eff(z) = H_PP +H_PQ(z-H_QQ)^-1H_QP. Then P(z-H)^-1P = (z-H_eff(z))^-1 where the left side is restricted to P H, the right side is an inverse on that retained space, and both are written in the same orthonormal basis. Here z-H_QQ and z-H_eff abbreviate the appropriately sized scalar matrices minus the indicated blocks.

    Exact mathematical passage
    zI_Q-H_{QQ}
I_{\rm in}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 1083

    labelstrong:standardfact:001 A linear map Φ:M_n( C)→ M_m( C) is completely positive exactly when it has a Kraus representation Φ(X)=∑_rK_rXK_r^*. It is trace preserving exactly when ∑_rK_r^*K_r=I. Equivalently, its Choi matrix J(Φ) = ∑_i,jΦ(ketibraj)⊗ketibraj is positive, and trace preservation is Tr_rm outJ(Φ)=I_rm in.

    Exact mathematical passage
    
    \Tr_{\rm out}J(\Phi)=I_{\rm in}.
    
\idUse in source · 6 passages

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  • Use in source · monograph_atlas.tex, line 330

    vpage18An ancilla tests more than positivityWHY COMPLETE POSITIVITY IS THE RELEVANT CONDITIONTraditional edition: Classical input II.7.7. Ordinary transpose T sends a positive matrix on one system to another positive matrix and preserves its trace. Those properties are insufficient for a quantum channel on a subsystem of an entangled state. The test must include id⊗ T on the larger system. vfigcomplete_positivity Apply this extended map to the Bell density matrix. The result is (id⊗ T)(ρ_rm Bell…

    Exact mathematical passage
    \id\otimes\mathsf T
\ii^{-jk}Use in source · 1 passage

Search aliases: ii^-jk i^-jk ii mathrm

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  • Use in source · monograph_atlas.tex, line 93

    vpage6Four phases resolve a cyclic shiftCHARACTER PROJECTORS YOU CAN MULTIPLYTraditional edition: Corollary II.3.3. On four sites, let Sket k=ketk+1bmod4 and let ω= i. The character projectors are the exact matrices P_j=frac14∑_r=0^3 i^-jrS^r, v_j(k)=frac12 i^-jk, P_j=v_jv_j^*. All entries belong to the Gaussian rationals. Thus no approximation to a root of unity is needed in this model. vfigcyclic_four headReading the columns Each column v_j is a normalized wave around the four sites. Advancing…

    Exact mathematical passage
    
    P_j=\frac14\sum_{r=0}^3\ii^{-jr}S^r,
    \qquad v_j(k)=\frac12\ii^{-jk},\qquad P_j=v_jv_j^*.
    
\ii^{-jr}Use in source · 1 passage

Search aliases: ii^-jr i^-jr ii mathrm

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  • Use in source · monograph_atlas.tex, line 93

    vpage6Four phases resolve a cyclic shiftCHARACTER PROJECTORS YOU CAN MULTIPLYTraditional edition: Corollary II.3.3. On four sites, let Sket k=ketk+1bmod4 and let ω= i. The character projectors are the exact matrices P_j=frac14∑_r=0^3 i^-jrS^r, v_j(k)=frac12 i^-jk, P_j=v_jv_j^*. All entries belong to the Gaussian rationals. Thus no approximation to a root of unity is needed in this model. vfigcyclic_four headReading the columns Each column v_j is a normalized wave around the four sites. Advancing…

    Exact mathematical passage
    
    P_j=\frac14\sum_{r=0}^3\ii^{-jr}S^r,
    \qquad v_j(k)=\frac12\ii^{-jk},\qquad P_j=v_jv_j^*.
    
\ii^jUse in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 100

    character projectors are the exact matrices P_j=frac14∑_r=0^3 i^-jrS^r, v_j(k)=frac12 i^-jk, P_j=v_jv_j^*. All entries belong to the Gaussian rationals. Thus no approximation to a root of unity is needed in this model. vfigcyclic_four headReading the columns Each column v_j is a normalized wave around the four sites. Advancing the address multiplies it by i^j. The entries show phase differences rather than four different probability distributions: every column has uniform site probability 1/4.

    Exact mathematical passage
    \ii^j
\ImUse in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 653

    1 · 2, so A=0, B=1, and D=2. In its elimination domain, Σ(z)=1/(z-2). At z=3+ i, Σ(3+ i)=frac1- i2, ImΣ(z)=-(Im z)|(z-2)^-1|^2≤0. The sign in the upper half plane comes from self-adjoint hidden data. It is not an entrywise sign condition on an arbitrary effective matrix. xfigstability headA stability estimate with a common spectral gap Compare (B,D)=(1,2) with (widetilde B,widetilde D)=(9/8,17/8) at z=3. Both hidden spectral distances are at least δ=3/4, and both couplings are bounded by g=9/8. …

    Exact mathematical passage
    
    \Sigma(3+\ii)=\frac{1-\ii}{2},\qquad
    \Im\Sigma(z)=-(\Im z)\left|(z-2)^{-1}\right|^2\leq0.
    
\operatorname{Im}Use in source · 2 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 1576

    [Upper half plane sign] If Imz>0, then ImΣ(z) = -(Imz) B(z-D)^-1(overline z-D)^-1B^* ≤0. Thus -Σ is an operator valued Herglotz function.

    Exact mathematical passage
    \operatorname{Im}z>0
\operatorname{im}Use in source · 1 passage

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  • Use in source · constraint_image.tex, line 8

    same constraints;node[rotate=90,font=footnotesize] at (11.4,1.7) new coordinate; node[font=small] at (6,0.15) closure on imR transfers, and the new complement needs its own test;

    Exact mathematical passage
    \operatorname{im}R
\ipUse in source · 11 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 457

    [Path interference formula] Fix a source vector ψ∈ P_a_0 H and a target packet b. Let Γ_b be the set of packet paths from a_0 to b, and set η_γ=U_γψ. Choose any total order on this finite path set. Then normP_bUψ^2 = ∑_γ∈Γ_bnormη_γ^2 + 2Re ∑_substackγ,γ'∈Γ_b γ<γ' ipη_γη_γ'. Consequently, normP_bUψ ≤ ∑_γ∈Γ_bnormη_γ. If the path outputs are pairwise orthogonal, the target probability is the sum of the path probabilities.

    Exact mathematical passage
    
    \norm{P_bU\psi}^2
    =
    \sum_{\gamma\in\Gamma_b}\norm{\eta_\gamma}^2
    +
    2\operatorname{Re}
    \sum_{\substack{\gamma,\gamma'\in\Gamma_b\\ \gamma<\gamma'}}
    \ip{\eta_\gamma}{\eta_{\gamma'}}.
    
JUse in source · 20 passages

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  • Use in source · monograph_atlas.tex, line 217

    -sin t. The vector has not moved in the laboratory, but its coordinate entries have changed. vfigmoving_frame headThe missing term can be computed exactly Let J=mat0 · -1 1 · 0. Since U^*dot U=J, the coordinate Hamiltonian is H_rm frame=- i J=mat0 · i

    Exact mathematical passage
    J=\mat{0&-1\\1&0}
\bm jUse in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 343

    Suppose the ath tensor factor carries a cyclic packet family (P_j^(a))_j∈ Z/N Z. The fine tensor packets are P_ j^rm fine = P_j_1^(1)⊗⋯⊗ P_j_m^(m).

    Exact mathematical passage
    
    P_{\bm j}^{\rm fine}
    =
    P_{j_1}^{(1)}\otimes\cdots\otimes P_{j_m}^{(m)}.
    
\mathbf jUse in source · 1 passage

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  • Use in source · Read passage · 01_finite_core.tex, line 239

    Fix N≥1. Suppose every factor a has a complete orthogonal family P^(a)_0,…,P^(a)_N-1. The fine tensor packets are P_ j^fine = P^(1)_j_1⊗⋯⊗ P^(m)_j_m.

    Exact mathematical passage
    
    P_{\mathbf j}^{\mathrm{fine}}
    =
    P^{(1)}_{j_1}\otimes\cdots\otimes P^{(m)}_{j_m}.
    
J^2Use in source · 1 passage

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  • Use in source · Read passage · 01_finite_core.tex, line 411

    J · 0 . Therefore Spec H_even ={±sqrt4h^2+J^2}, Spec H_odd={± J}.

    Exact mathematical passage
    
    \Spec H_{\mathrm{even}}
    =\{\pm\sqrt{4h^2+J^2}\},
    \qquad
    \Spec H_{\mathrm{odd}}=\{\pm J\}.
    
j_1Use in source · 4 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 239

    Fix N≥1. Suppose every factor a has a complete orthogonal family P^(a)_0,…,P^(a)_N-1. The fine tensor packets are P_ j^fine = P^(1)_j_1⊗⋯⊗ P^(m)_j_m.

    Exact mathematical passage
    
    P_{\mathbf j}^{\mathrm{fine}}
    =
    P^{(1)}_{j_1}\otimes\cdots\otimes P^{(m)}_{j_m}.
    
j_mUse in source · 4 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 239

    Fix N≥1. Suppose every factor a has a complete orthogonal family P^(a)_0,…,P^(a)_N-1. The fine tensor packets are P_ j^fine = P^(1)_j_1⊗⋯⊗ P^(m)_j_m.

    Exact mathematical passage
    
    P_{\mathbf j}^{\mathrm{fine}}
    =
    P^{(1)}_{j_1}\otimes\cdots\otimes P^{(m)}_{j_m}.
    
j_rUse in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 2476

    [Reflection positivity is closed under limits] Suppose C_n(j,k) are reflection positive kernels on N, meaning every finite matrix (C_n(j_r,j_s))_r,s is positive semidefinite. If C_n(j,k)⟶ C(j,k) for every pair, then C is reflection positive.

    Exact mathematical passage
    
    \bigl(C_n(j_r,j_s)\bigr)_{r,s}
    
j_sUse in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 2476

    [Reflection positivity is closed under limits] Suppose C_n(j,k) are reflection positive kernels on N, meaning every finite matrix (C_n(j_r,j_s))_r,s is positive semidefinite. If C_n(j,k)⟶ C(j,k) for every pair, then C is reflection positive.

    Exact mathematical passage
    
    \bigl(C_n(j_r,j_s)\bigr)_{r,s}
    
K'Use in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 442

    vpage24A dimension curve is a scale diagnosticTHE EXACT HEAT TRACE ON FOUR SITESTraditional edition: Definition II.11.1, Proposition II.11.2. For the Laplacian on a cycle with four sites L=2I-S-S^*, the eigenvalues are 0,2,2,4. The normalized heat trace and its diagnostic of spectral dimension are therefore K(τ)=frac1+2e^-2τ+e^-4τ4 =frac(1+e^-2τ)^24, d_s(τ)=-2τfracK'(τ)K(τ) =frac8τe^2τ+1. No numerical differentiation is needed for this finite example. vfigspectral_dimension headBoth ends reflect…

    Exact mathematical passage
    
    K(\tau)=\frac{1+2e^{-2\tau}+e^{-4\tau}}4
    =\frac{(1+e^{-2\tau})^2}4,
    \qquad
     d_s(\tau)=-2\tau\frac{K'(\tau)}{K(\tau)}
    =\frac{8\tau}{e^{2\tau}+1}.
    
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  • Use in source · Read passage · 02_strengthened.tex, line 719

    Differentiate V=W^*U. Since dot W=KW and K^*=-K, dot W^*=-W^*K. Substitution gives the equation. The first term in H_rm mov is self adjoint. The operator - i W^*dot W is self adjoint because W^*dot W is skew adjoint.

    Exact mathematical passage
    K^*=-K
K^2Use in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 454

    For the Cartesian product of two identical cycles with four sites, the Laplacian eigenvalues add and the heat traces multiply: K_2=K^2. Consequently d_s,2=2d_s exactly. The product identity determines the second curve exactly from the first.

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    K_2=K^2
k^2Use in source · 9 passages

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  • Use in source · monograph_atlas.tex, line 460

    vpage25Refine the grid while holding the mode fixedAN EXACT ERROR ENCLOSURE, NOT A FITTED SLOPETraditional edition: Theorem II.11.4. For the circle symbol, the continuum value is k^2 and the grid value is λ_k,h=frac4h^2sin^2 (frackh2), h≠0. For a fixed low mode, the paper bounds the error by 0≤ k^2-λ_k,h≤ k^4h^2/12. The spacing condition matters because the displayed expression divides by h^2. vfigdispersion headWhat is certified in the displayed table? Take k=1 and h=1/4,1/8,1/16. For x=h/2∈[0,…

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    k^2
k^4Use in source · 6 passages

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  • Use in source · monograph_atlas.tex, line 464

    vpage25Refine the grid while holding the mode fixedAN EXACT ERROR ENCLOSURE, NOT A FITTED SLOPETraditional edition: Theorem II.11.4. For the circle symbol, the continuum value is k^2 and the grid value is λ_k,h=frac4h^2sin^2 (frackh2), h≠0. For a fixed low mode, the paper bounds the error by 0≤ k^2-λ_k,h≤ k^4h^2/12. The spacing condition matters because the displayed expression divides by h^2. vfigdispersion headWhat is certified in the displayed table? Take k=1 and h=1/4,1/8,1/16. For x=h/2∈[0,…

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    0\le k^2-\lambda_{k,h}\le k^4h^2/12
K_0Use in source · 5 passages

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  • Use in source · monograph_atlas.tex, line 312

    vpage17A channel acts on four matrix entriesPOPULATIONS AND COHERENCES TRANSFORM DIFFERENTLYTraditional edition: Theorem II.7.6, Example II.7.12. Choose amplitude damping with γ=9/25: K_0=mat1 · 0 0 · 4/5, K_1=mat0 · 3/5 0 · 0, K_0^*K_0+K_1^*K_1=I. The channel Φ(ρ)=∑_aK_aρ K_a^* is trace preserving and completely positive. The special parameter keeps every displayed coefficient rational. vfigdamping The superoperator uses the entry order (ρ_00,ρ_01,ρ_10,ρ_11). Population leaves the excited state…

    Exact mathematical passage
    
    K_0=\mat{1&0\\0&4/5},\qquad
    K_1=\mat{0&3/5\\0&0},\qquad K_0^*K_0+K_1^*K_1=I.
    
K_0^*Use in source · 2 passages

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  • Use in source · monograph_atlas.tex, line 312

    vpage17A channel acts on four matrix entriesPOPULATIONS AND COHERENCES TRANSFORM DIFFERENTLYTraditional edition: Theorem II.7.6, Example II.7.12. Choose amplitude damping with γ=9/25: K_0=mat1 · 0 0 · 4/5, K_1=mat0 · 3/5 0 · 0, K_0^*K_0+K_1^*K_1=I. The channel Φ(ρ)=∑_aK_aρ K_a^* is trace preserving and completely positive. The special parameter keeps every displayed coefficient rational. vfigdamping The superoperator uses the entry order (ρ_00,ρ_01,ρ_10,ρ_11). Population leaves the excited state…

    Exact mathematical passage
    
    K_0=\mat{1&0\\0&4/5},\qquad
    K_1=\mat{0&3/5\\0&0},\qquad K_0^*K_0+K_1^*K_1=I.
    
K_1Use in source · 6 passages

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  • Use in source · monograph_atlas.tex, line 312

    vpage17A channel acts on four matrix entriesPOPULATIONS AND COHERENCES TRANSFORM DIFFERENTLYTraditional edition: Theorem II.7.6, Example II.7.12. Choose amplitude damping with γ=9/25: K_0=mat1 · 0 0 · 4/5, K_1=mat0 · 3/5 0 · 0, K_0^*K_0+K_1^*K_1=I. The channel Φ(ρ)=∑_aK_aρ K_a^* is trace preserving and completely positive. The special parameter keeps every displayed coefficient rational. vfigdamping The superoperator uses the entry order (ρ_00,ρ_01,ρ_10,ρ_11). Population leaves the excited state…

    Exact mathematical passage
    
    K_0=\mat{1&0\\0&4/5},\qquad
    K_1=\mat{0&3/5\\0&0},\qquad K_0^*K_0+K_1^*K_1=I.
    
K_1^*Use in source · 2 passages

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  • Use in source · monograph_atlas.tex, line 312

    vpage17A channel acts on four matrix entriesPOPULATIONS AND COHERENCES TRANSFORM DIFFERENTLYTraditional edition: Theorem II.7.6, Example II.7.12. Choose amplitude damping with γ=9/25: K_0=mat1 · 0 0 · 4/5, K_1=mat0 · 3/5 0 · 0, K_0^*K_0+K_1^*K_1=I. The channel Φ(ρ)=∑_aK_aρ K_a^* is trace preserving and completely positive. The special parameter keeps every displayed coefficient rational. vfigdamping The superoperator uses the entry order (ρ_00,ρ_01,ρ_10,ρ_11). Population leaves the excited state…

    Exact mathematical passage
    
    K_0=\mat{1&0\\0&4/5},\qquad
    K_1=\mat{0&3/5\\0&0},\qquad K_0^*K_0+K_1^*K_1=I.
    
K_2Use in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 454

    For the Cartesian product of two identical cycles with four sites, the Laplacian eigenvalues add and the heat traces multiply: K_2=K^2. Consequently d_s,2=2d_s exactly. The product identity determines the second curve exactly from the first.

    Exact mathematical passage
    K_2=K^2
K_aUse in source · 13 passages

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  • Use in source · monograph_atlas.tex, line 30

    K_a · Kraus operator · It describes one channel branch and need not be a projector.

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    K_a
K_a^*Use in source · 8 passages

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  • Use in source · monograph_atlas.tex, line 316

    0 · 0, K_0^*K_0+K_1^*K_1=I. The channel Φ(ρ)=∑_aK_aρ K_a^* is trace preserving and completely positive. The special parameter keeps every displayed coefficient rational. vfigdamping The superoperator uses the entry order (ρ_00,ρ_01,ρ_10,ρ_11). Population leaves the excited state with factor 9/25, while coherences contract by 4/5. These are not the same rate or the same coordinate.

    Exact mathematical passage
    \Phi(\rho)=\sum_aK_a\rho K_a^*
K_jUse in source · 6 passages

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  • Use in source · Read passage · monograph_examples.tex, line 17

    e, and the plotted values are exact fractions. The example shows why direct compression and resolvent elimination give different results. Normalization changes the map. Let P=|0⟩⟨0| on C^2 and Z=diag(1,-1). The normalized Kraus family sqrt3/4 I, sqrt1/4 Z satisfies ∑_j K_j^*K_j=I and maps P to P. The unnormalized family sqrt3 I, Z satisfies ∑_j E_j^*E_j=4I and maps P to 4P. The two families have the same relative weights, but their total normalization differs. Both outputs are proportional to th…

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    \sum_j K_j^*K_j=I
k_jUse in source · 2 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 2022

    Let N≥2 and let Λ_N=( Z/N Z)^d be the unit flat torus grid with spacing 1/N. The standard periodic difference Laplacian has eigenvalues λ_N(k) = 4N^2 ∑_j=1^d sin^2(fracπ k_jN), where k runs through centered residue representatives. This is the standard periodic finite difference Laplacian [source reference].

    Exact mathematical passage
    
    \lambda_N(k)
    =
    4N^2
    \sum_{j=1}^{d}
    \sin^2\left(\frac{\pi k_j}{N}\right),
    
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  • Use in source · Read passage · monograph_examples.tex, line 17

    e, and the plotted values are exact fractions. The example shows why direct compression and resolvent elimination give different results. Normalization changes the map. Let P=|0⟩⟨0| on C^2 and Z=diag(1,-1). The normalized Kraus family sqrt3/4 I, sqrt1/4 Z satisfies ∑_j K_j^*K_j=I and maps P to P. The unnormalized family sqrt3 I, Z satisfies ∑_j E_j^*E_j=4I and maps P to 4P. The two families have the same relative weights, but their total normalization differs. Both outputs are proportional to th…

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    \sum_j K_j^*K_j=I
k_j^4Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 2033

    [Low mode dispersion in dimension d] For every centered mode k, 0 ≤ 4π^2absk^2-λ_N(k) ≤ frac4π^43N^2 ∑_j=1^dk_j^4.

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    0
    \leq
    4\pi^2\abs{k}^2-\lambda_N(k)
    \leq
    \frac{4\pi^4}{3N^2}
    \sum_{j=1}^{d}k_j^4.
    
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  • Use in source · Read passage · 01_finite_core.tex, line 723

    [Finite Kraus channel] Let K_1,…,K_r satisfy ∑_aK_a^*K_a=I. Then Φ(ρ)=∑_aK_aρ K_a^* is completely positive and trace preserving.

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    K_1,\ldots,K_r
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  • Use in source · Read passage · 01_finite_core.tex, line 855

    _rδ_rsP. If λ_r=0, F_r^*F_r=0 forces F_r=0. For positive eigenvalues only, set V_r=F_r/sqrtλ_r. These satisfy V_rP=V_r, V_r^*V_s=δ_rsP. Let S=∑_λ_r>0V_rV_r^*. Orthogonality makes S an orthogonal projector. Use the recovery branches K_r=V_r^*, K_unused=I-S. They are complete on the whole ambient space because ∑_rK_r^*K_r+K_unused^*K_unused =S+(I-S)^2=I. The inverse unitary change of coordinates reconstructs each E_aP from the F_r. Every recovery branch of a coherent combination is therefore scala…

    Exact mathematical passage
    
    \sum_rK_r^*K_r+K_{\mathrm{unused}}^*K_{\mathrm{unused}}
    =S+(I-S)^2=I.
    
K_{\mathrm{unused}}Use in source · 2 passages

Search aliases: K_unused mathrm

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  • Use in source · Read passage · 01_finite_core.tex, line 851

    efine compressed transformed errors F_r=∑_aU_arE_aP. Then F_rP=F_r and F_r^*F_s=λ_rδ_rsP. If λ_r=0, F_r^*F_r=0 forces F_r=0. For positive eigenvalues only, set V_r=F_r/sqrtλ_r. These satisfy V_rP=V_r, V_r^*V_s=δ_rsP. Let S=∑_λ_r>0V_rV_r^*. Orthogonality makes S an orthogonal projector. Use the recovery branches K_r=V_r^*, K_unused=I-S. They are complete on the whole ambient space because ∑_rK_r^*K_r+K_unused^*K_unused =S+(I-S)^2=I. The inverse unitary change of coordinates reconstructs each E_aP…

    Exact mathematical passage
    
    K_r=V_r^*,\qquad K_{\mathrm{unused}}=I-S.
    
K_{\mathrm{unused}}^*Use in source · 1 passage

Search aliases: K_unused^* mathrm

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  • Use in source · Read passage · 01_finite_core.tex, line 855

    _rδ_rsP. If λ_r=0, F_r^*F_r=0 forces F_r=0. For positive eigenvalues only, set V_r=F_r/sqrtλ_r. These satisfy V_rP=V_r, V_r^*V_s=δ_rsP. Let S=∑_λ_r>0V_rV_r^*. Orthogonality makes S an orthogonal projector. Use the recovery branches K_r=V_r^*, K_unused=I-S. They are complete on the whole ambient space because ∑_rK_r^*K_r+K_unused^*K_unused =S+(I-S)^2=I. The inverse unitary change of coordinates reconstructs each E_aP from the F_r. Every recovery branch of a coherent combination is therefore scala…

    Exact mathematical passage
    
    \sum_rK_r^*K_r+K_{\mathrm{unused}}^*K_{\mathrm{unused}}
    =S+(I-S)^2=I.
    
\KerUse in source · 4 passages

Search aliases: Ker operatorname

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\mathcal LUse in source · 1 passage

Search aliases: L mathcal

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  • Use in source · Read passage · 03_supplement_04.tex, line 49

    Actual projected differentiation and curvature. Let E,F be real normed spaces. Let P:E→ L(F,F) be differentiable with P(x)^2=P(x) for every x. Let s:E→ F be C^2 with P(x)s(x)=s(x), and let X,Y:E→ E be differentiable vector fields. The checked connection is the actual expression ∇_Xs(x)=P(x) Ds(x)[X(x)]. It is proved to preserve the range condition. It is linear in the vector field direction and obeys the scalar Leibniz rule ∇_X(cs)=Dc[X] s+c∇_Xs for differentiable real scalar functions c. No dif…

    Exact mathematical passage
    P:E\to\mathcal L(F,F)
L_jUse in source · 3 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 823

    textitNecessity. Fix an error E_a and let L_j=K_jE_aP. Perfect recovery on rank-one code operators gives ∑_jketL_jψbraL_jψ =t_aketψbraψ (ψ∈ C). For every vector orthogonal to ψ, the quadratic form on the left is a sum of nonnegative squared absolute values and equals zero. Each L_jψ therefore lies in the span of ψ. A linear operator that preserves every line in C is scalar there: apply it to two independent vectors and their sum. The one-dimensional case is immediate, and the claim is vacuous fo…

    Exact mathematical passage
    L_j=K_jE_aP
L_NUse in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 2153

    [Rigorous intermediate dimension window] For every ε>0, there is a diffusion time t_ε>0 and an integer N_ε such that absd_L_N(t_ε)-d<ε for every N≥ N_ε.

    Exact mathematical passage
    
    \abs{d_{L_N}(t_\varepsilon)-d}<\varepsilon
    
L_nUse in source · 4 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 2511

    [Heat trace convergence from trace norm] Let L_n,L be nonnegative self adjoint operators on one Hilbert space. For a fixed t>0, assume their heat operators are trace class and that e^-tL_n⟶ e^-tL in trace norm. Then Tr( e^-tL_n)⟶Tr( e^-tL). If also the heat moment operators are trace class and L_n e^-tL_n⟶ L e^-tL in trace norm and the limiting heat trace is nonzero, then the spectral dimensions defined by the heat moment ratio converge at that time.

    Exact mathematical passage
    L_n,L
L_rUse in source · 4 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 1214

    [Finite Lindblad generator] A norm continuous semigroup of completely positive trace preserving maps on a finite matrix algebra, in the Schr odinger picture, has a generator of the form G(X) = - i[H,X] + ∑_r ( L_rXL_r^* - frac12L_r^*L_rX - frac12XL_r^*L_r ), where H=H^*. Conversely, every operator of this form generates a completely positive trace preserving semigroup [source reference].

    Exact mathematical passage
    
    \Gcal(X)
    =
    -\ii[H,X]
    +
    \sum_r
    \left(
    L_rXL_r^*
    -
    \frac12L_r^*L_rX
    -
    \frac12XL_r^*L_r
    \right),
    
L_r^*Use in source · 3 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 1214

    [Finite Lindblad generator] A norm continuous semigroup of completely positive trace preserving maps on a finite matrix algebra, in the Schr odinger picture, has a generator of the form G(X) = - i[H,X] + ∑_r ( L_rXL_r^* - frac12L_r^*L_rX - frac12XL_r^*L_r ), where H=H^*. Conversely, every operator of this form generates a completely positive trace preserving semigroup [source reference].

    Exact mathematical passage
    
    \Gcal(X)
    =
    -\ii[H,X]
    +
    \sum_r
    \left(
    L_rXL_r^*
    -
    \frac12L_r^*L_rX
    -
    \frac12XL_r^*L_r
    \right),
    
\LcalUse in source · 9 passages

Search aliases: Lcal L mathcal

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  • Use in source · monograph_atlas.tex, line 580

    vpage31Coherence order survives a covariant channelCHANNEL, CHOI, AND GENERATOR CHECKSTraditional edition: Theorem II.7.8, Theorem II.7.10, Theorem II.7.14. Take S=Z=diag(1,-1) on C^2. Under conjugation X↦ ZXZ, diagonal matrices have coherence order zero and off-diagonal matrices have coherence order one modulo two. Its projectors on Hilbert--Schmidt operator space are L_0(X)=(X+ZXZ)/2 and L_1(X)=(X-ZXZ)/2.

    Exact mathematical passage
    \Lcal_0(X)=(X+ZXZ)/2
\Lcal_0Use in source · 1 passage

Search aliases: Lcal_0 L_0 Lcal mathcal

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  • Use in source · monograph_atlas.tex, line 580

    vpage31Coherence order survives a covariant channelCHANNEL, CHOI, AND GENERATOR CHECKSTraditional edition: Theorem II.7.8, Theorem II.7.10, Theorem II.7.14. Take S=Z=diag(1,-1) on C^2. Under conjugation X↦ ZXZ, diagonal matrices have coherence order zero and off-diagonal matrices have coherence order one modulo two. Its projectors on Hilbert--Schmidt operator space are L_0(X)=(X+ZXZ)/2 and L_1(X)=(X-ZXZ)/2.

    Exact mathematical passage
    \Lcal_0(X)=(X+ZXZ)/2
\Lcal_1Use in source · 1 passage

Search aliases: Lcal_1 L_1 Lcal mathcal

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  • Use in source · monograph_atlas.tex, line 580

    er survives a covariant channelCHANNEL, CHOI, AND GENERATOR CHECKSTraditional edition: Theorem II.7.8, Theorem II.7.10, Theorem II.7.14. Take S=Z=diag(1,-1) on C^2. Under conjugation X↦ ZXZ, diagonal matrices have coherence order zero and off-diagonal matrices have coherence order one modulo two. Its projectors on Hilbert--Schmidt operator space are L_0(X)=(X+ZXZ)/2 and L_1(X)=(X-ZXZ)/2.

    Exact mathematical passage
    \Lcal_1(X)=(X-ZXZ)/2
\Lcal_pUse in source · 2 passages

Search aliases: Lcal_p L_p Lcal mathcal

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  • Use in source · Read passage · 02_strengthened.tex, line 1241

    [Charge preservation by a Lindblad generator] Let S be unitary and N≥1 an integer with S^N=I. Assume SHS^*=H and, for every jump operator, there is a charge q_r such that SL_rS^*=ω^q_rL_r. Then the Lindblad generator G preserves every coherence order: G L_p= L_p G. The quantum dynamical semigroup e^t G has the same property.

    Exact mathematical passage
    
    \Gcal\Lcal_p=\Lcal_p\Gcal.
    
\Lcal_qUse in source · 5 passages

Search aliases: Lcal_q L_q Lcal mathcal

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  • Use in source · Read passage · 02_strengthened.tex, line 1099

    [Coherence order projectors] For q∈ Z/N Z, define L_q(X) = frac1N ∑_r=0^N-1 ω^-qrS^rXS^-r. Then the L_q form a complete orthogonal packet system on Hilbert Schmidt operator space. Their ranges are the operators satisfying SXS^*=ω^qX. If P_j are the state charge projectors, then Ran L_q = ⊕_jP_j+qEnd( H)P_j.

    Exact mathematical passage
    
    \Lcal_q(X)
    =
    \frac1N
    \sum_{r=0}^{N-1}
    \omega^{-qr}S^rXS^{-r}.
    
\limUse in source · 2 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 1972

    [Finite scale limits] For every finite nonnegative L with nontrivial kernel, lim_tdownarrow0d_L(t)=0 and lim_t→∞d_L(t)=0. For every t>0, 0≤ d_L(t)≤2tnorm L.

    Exact mathematical passage
    
    \lim_{t\downarrow0}d_L(t)=0
    
\lim_{t\downarrow0}Use in source · 1 passage

Search aliases: lim_tdownarrow0 lim downarrow

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  • Use in source · Read passage · 02_strengthened.tex, line 1972

    [Finite scale limits] For every finite nonnegative L with nontrivial kernel, lim_tdownarrow0d_L(t)=0 and lim_t→∞d_L(t)=0. For every t>0, 0≤ d_L(t)≤2tnorm L.

    Exact mathematical passage
    
    \lim_{t\downarrow0}d_L(t)=0
    
\lim_{t\to\infty}Use in source · 1 passage

Search aliases: lim_t→∞ lim to infty

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  • Use in source · Read passage · 02_strengthened.tex, line 1976

    [Finite scale limits] For every finite nonnegative L with nontrivial kernel, lim_tdownarrow0d_L(t)=0 and lim_t→∞d_L(t)=0. For every t>0, 0≤ d_L(t)≤2tnorm L.

    Exact mathematical passage
    
    \lim_{t\to\infty}d_L(t)=0.
    
\log_{10}Use in source · 1 passage

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  • Use in source · spectral_dimension.tex, line 26

    125); node[font=small,align=center,anchor=east,font=scriptsize] at (0.64,2.1125) 1; draw[black!13,line width=.25pt] (0.8,3.425) -- (9.5,3.425); node[font=small,align=center,anchor=east,font=scriptsize] at (0.64,3.425) 2; draw[->,line width=.6pt] (0.8,0.8) -- (9.62,0.8); draw[->,line width=.6pt] (0.8,0.8) -- (0.8,4.07); node[font=small,align=center,font=scriptsize] at (5.15,0.25) log_10τ; node[font=small,align=center,anchor=west,font=scriptsize] at (0.8,4.35) d_s(τ); draw[line width=1.1pt] plot c…

    Exact mathematical passage
    \log_{10}\tau
\LongleftrightarrowUse in source · 6 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 1542

    [Spectral equivalence] Let z∉Spec D. Then z∈Spec H Longleftrightarrow 0∈Spec F_P(z). The map x⟼ x

    Exact mathematical passage
    
    z\in\Spec H
    \quad\Longleftrightarrow\quad
    0\in\Spec F_P(z).
    
\LongrightarrowUse in source · 3 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 803

    We call a recovery complete when it is a Kraus map R(X)=∑_jK_jXK_j^*, ∑_jK_j^*K_j=I. The family is exactly correctable when one such recovery works for every coherent error combination A_w=∑_aw_aE_a: for every w there is a real t_w≥0, independent of the logical input, such that PXP=X Longrightarrow R(A_wXA_w^*)=t_wX. The coefficient is an unnormalized weight. It is not necessarily a probability for an arbitrary matrix A_w.

    Exact mathematical passage
    
    PXP=X\quad\Longrightarrow\quad
    \cR(A_wXA_w^*)=t_wX.
    
M_2Use in source · 2 passages

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  • Use in source · monograph_atlas.tex, line 74

    vpage5Why one seed is not always enoughAN EXACT MULTIPLICITY LOWER BOUNDTraditional edition: Theorem II.2.3. Consider M_2( C)⊗ I_3 acting on C^2⊗ C^3. A seed is a 2×3 coefficient matrix. Its two rows span at most two directions in the three-dimensional multiplicity factor. Therefore no single seed is cyclic for this algebra. C_1=mat1 · 0 · 0

    Exact mathematical passage
    M_2(\CC)\otimes I_3
M_dUse in source · 8 passages

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  • Use in source · monograph_atlas.tex, line 61

    ment changes the local spanSCHMIDT RANK AS ACCESSIBLE MULTIPLICITYTraditional edition: Theorem II.2.2, Corollary II.2.4. Write a bipartite vector as a coefficient matrix C, with the first subsystem indexing rows. Acting only on that subsystem transforms C to AC. Every resulting row remains in the row space of C, and every independent choice of such rows can be obtained in this way. dimSpan{(A⊗ I)ψ:A∈ M_d( C)} =d rank C. vfiglocal_orbits The product vector ket00 has matrix C=diag(1,0). Its local …

    Exact mathematical passage
    
    \dim\Span\{(A\otimes I)\psi:A\in M_d(\CC)\}
    =d\,\rank C.
    
M_{d_A}Use in source · 2 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 138

    [Local orbit and Schmidt rank] Let ψ∈ H_A⊗ H_B, with dim H_A=d_A≥1, and let r be its Schmidt rank. The reduced positive operator on B is ρ_B=Tr_A(ketψbraψ). Normalization of ψ does not affect its support. Then dimspan{(A⊗ I_B)ψ:A∈ M_d_A( C)} =d_A r. In particular, local operators on A generate the complete bipartite Hilbert space exactly when the reduced state on B has full support.

    Exact mathematical passage
    
    \boxed{
    \dim\operatorname{span}\{(A\otimes I_B)\psi:A\in M_{d_A}(\bbC)\}
    =d_A r.
    }
    
M_{d_r}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 104

    Let A ≅ ⊕_r=1^s (M_d_r( C)⊗ I_m_r) act on H ≅ ⊕_r=1^s ( C^d_r⊗ C^m_r). Assume d_r,m_r≥1 for each displayed block. For an empty block family, the seed rank and the displayed finite supremum are defined as zero. A vector in one block is identified with a d_r by m_r coefficient matrix.

    Exact mathematical passage
    
    \Acal
    \cong
    \bigoplus_{r=1}^{s}
    \bigl(M_{d_r}(\CC)\otimes I_{m_r}\bigr)
    
M_{d\times m}Use in source · 2 passages

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  • Use in source · Read passage · 03_supplement_03.tex, line 2

    Actual orbits and sharp seed counts. Let C∈ M_d× m( C) be the coefficient matrix of one seed. Define its orbit by actual matrix multiplication: O(C)={AC:A∈ M_d( C)}. This set is already a linear subspace. The source proves that it equals the linear span of the orbit before computing its dimension.

    Exact mathematical passage
    C\in M_{d\times m}(\C)
M_mUse in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 1068

    [Finite Kraus and Choi criteria] A linear map Φ:M_n( C)→ M_m( C) is completely positive exactly when it has a Kraus representation Φ(X)=∑_rK_rXK_r^*. It is trace preserving exactly when ∑_rK_r^*K_r=I. Equivalently, its Choi matrix J(Φ) = ∑_i,jΦ(ketibraj)⊗ketibraj is positive, and trace preservation is Tr_rm outJ(Φ)=I_rm in.

    Exact mathematical passage
    \Phi:M_n(\CC)\to M_m(\CC)
M_nUse in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 1068

    [Finite Kraus and Choi criteria] A linear map Φ:M_n( C)→ M_m( C) is completely positive exactly when it has a Kraus representation Φ(X)=∑_rK_rXK_r^*. It is trace preserving exactly when ∑_rK_r^*K_r=I. Equivalently, its Choi matrix J(Φ) = ∑_i,jΦ(ketibraj)⊗ketibraj is positive, and trace preservation is Tr_rm outJ(Φ)=I_rm in.

    Exact mathematical passage
    \Phi:M_n(\CC)\to M_m(\CC)
m_rUse in source · 7 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 104

    Let A ≅ ⊕_r=1^s (M_d_r( C)⊗ I_m_r) act on H ≅ ⊕_r=1^s ( C^d_r⊗ C^m_r). Assume d_r,m_r≥1 for each displayed block. For an empty block family, the seed rank and the displayed finite supremum are defined as zero. A vector in one block is identified with a d_r by m_r coefficient matrix.

    Exact mathematical passage
    
    \Acal
    \cong
    \bigoplus_{r=1}^{s}
    \bigl(M_{d_r}(\CC)\otimes I_{m_r}\bigr)
    
M_\muUse in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 225

    Complete reducibility gives a unitary decomposition H ≅ ⊕_μ∈widehat G V_μ⊗ M_μ, U(g) ≅ ⊕_μ π_μ(g)⊗ I_M_μ. On the μ summand, the displayed average is central in the irreducible representation π_μ, so it is a scalar by Schur's lemma. Taking its trace and applying character orthogonality shows that the scalar is one when μ=λ and zero otherwise. The asserted identities follow on the direct sum.

    Exact mathematical passage
    
    \Hcal
    \cong
    \bigoplus_{\mu\in\widehat G}
    V_\mu\otimes M_\mu,
    \qquad
    U(g)
    \cong
    \bigoplus_\mu
    \pi_\mu(g)\otimes I_{M_\mu}.
    
\matUse in source · 21 passages

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  • Use in source · monograph_atlas.tex, line 75

    vpage5Why one seed is not always enoughAN EXACT MULTIPLICITY LOWER BOUNDTraditional edition: Theorem II.2.3. Consider M_2( C)⊗ I_3 acting on C^2⊗ C^3. A seed is a 2×3 coefficient matrix. Its two rows span at most two directions in the three-dimensional multiplicity factor. Therefore no single seed is cyclic for this algebra. C_1=mat1 · 0 · 0 0 · 1 · 0, C_2=mat0 · 0 · 1 0 · 0 · 0. These two matrices provide a complete set of row directions. Their individual orbit dimensions are four and two, and …

    Exact mathematical passage
    
    C_1=\mat{1&0&0\\0&1&0},\qquad
    C_2=\mat{0&0&1\\0&0&0}.
    
\mathbinUse in source · 2 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 647

    n convention A=-i⟨ u,du⟩ in a local unit frame. The associated scalar curvature density is F_μν =-iTr(P[∂_μ P,∂_ν P]). On the Bloch sphere, P(θ,ϕ) = frac12(I+ n(θ,ϕ)·σ), where n=(sinθcosϕ,sinθsinϕ,cosθ). The Pauli multiplication law gives [∂_θ P,∂_ϕ P] =fraci2(∂_θ nmathbin×∂_ϕ n)·σ. Using Tr(P a·σ)= n· a therefore yields F_θϕ =frac12 n·(∂_θ nmathbin×∂_ϕ n) =frac12sinθ. The scalar sign changes if the opposite convention for A is chosen. This explicit calculation is not a separate entry among the …

    Exact mathematical passage
    
    [\partial_\theta P,\partial_\phi P]
    =\frac{i}{2}(\partial_\theta\mathbf n\mathbin{\times}\partial_\phi\mathbf n)\cdot\boldsymbol\sigma.
    
\max_{1\le r\le s}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 135

    [Quantum seed rank] For the displayed multiplicity decomposition, srank_ A( H) = max_1≤ r≤ s lceilfracm_rd_rrceil.

    Exact mathematical passage
    
    \operatorname{srank}_{\Acal}(\Hcal)
    =
    \max_{1\le r\le s}
    \left\lceil\frac{m_r}{d_r}\right\rceil.
    
\max_rUse in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 147

    Set k=max_rlceilfracm_rd_rrceil. For each r, partition a basis of C^m_r into at most k groups of size at most d_r. Choose the coefficient matrix of the jth seed so that its row space spans the jth group. The combined row spaces span every multiplicity factor. The preceding theorem then shows that the k seeds generate every summand.

    Exact mathematical passage
    
    k=\max_r\left\lceil\frac{m_r}{d_r}\right\rceil.
    
\minUse in source · 7 passages

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  • Use in source · monograph_atlas.tex, line 198

    in(ε t)X, normQe^- i tHP=|sin(ε t)|, norm[H,P]=|ε|. The general commutator estimate becomes the elementary bound |sin u|≤ |u|. Unitarity also bounds the amplitude by one. vfigleakage headFrom a norm to a probability For this initial state, the escape probability is sin^2(ε t), not |sin(ε t)|. Consequently Pr(hidden packet at t)≤min{1,ε^2t^2}. At ε t=π/6, the amplitude is 1/2 and the probability is 1/4. Near zero, amplitudes are first order while escape probabilities are second order. Mixing thos…

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    \Pr(\text{hidden packet at }t)\le\min\{1,\varepsilon^2t^2\}.
    
\bm nUse in source · 3 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 891

    [Bloch sphere curvature] Let P(θ,ϕ) = frac12(I+ n(θ,ϕ)·σ), where n=(sinθcosϕ,sinθsinϕ,cosθ). With the convention F_θϕ =- iTr(P[∂_θ P,∂_ϕ P]), one has F_θϕ=frac12sinθ and frac12π ∫_0^2π∫_0^π F_θϕ dθ dϕ =1.

    Exact mathematical passage
    
    P(\theta,\phi)
    =
    \frac12\left(I+\bm n(\theta,\phi)\cdot\bm\sigma\right),
    
\mathbf nUse in source · 5 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 637

    For an orthogonal rank-one complex projector, use the scalar connection convention A=-i⟨ u,du⟩ in a local unit frame. The associated scalar curvature density is F_μν =-iTr(P[∂_μ P,∂_ν P]). On the Bloch sphere, P(θ,ϕ) = frac12(I+ n(θ,ϕ)·σ), where n=(sinθcosϕ,sinθsinϕ,cosθ). The Pauli multiplication law gives [∂_θ P,∂_ϕ P] =fraci2(∂_θ nmathbin×∂_ϕ n)·σ. Using Tr(P a·σ)= n· a therefore yields F_θϕ =frac12 n·(∂_θ nmathbin×∂_ϕ n) =frac12sinθ. The scalar sign changes if the opposite convention for A i…

    Exact mathematical passage
    
    P(\theta,\phi)
    =
    \frac12\left(I+\mathbf n(\theta,\phi)\cdot\boldsymbol\sigma\right),
    
\mathcal NUse in source · 5 passages

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  • Use in source · Read passage · 03_supplement_05.tex, line 3

    The precise finite channel statement. Let H= C^n be a finite coordinate space and let P=P^*=P^2. A matrix is code supported when Pρ P=ρ. For a finite family of square matrices E_a, put N_E(ρ)=∑_a E_aρ E_a^*. The input channel normalization is the actual matrix identity ∑_a E_a^*E_a=I. A finite Kraus recovery has the form R(σ)=∑_r R_rσ R_r^*, with ∑_rR_r^*R_r=I. This representation, together with the checked amplification results, provides complete positivity and trace preservation on the entire …

    Exact mathematical passage
    
    \mathcal N_E(\rho)=\sum_a E_a\rho E_a^*.
    
N^2Use in source · 4 passages

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  • Use in source · monograph_atlas.tex, line 725

    vpage37The dimension window has an order of limitsFINITE HEAT DATA AND THE QUANTIFIERSTraditional edition: Theorem II.11.5, Corollary II.11.8. For the unit circle grid with N sites, the scaled eigenvalues are λ_N(k)=4N^2sin^2(π k/N). Put Z_N(t)=∑_ke^-tλ_N(k) and d_N(t)=2t∑_kλ_N(k)e^-tλ_N(k)/Z_N(t).

    Exact mathematical passage
    \lambda_N(k)=4N^2\sin^2(\pi k/N)
n_1Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 1875

    [Finite reflection positivity] For vectors v_1,…,v_m∈ H and nonnegative integers n_1,…,n_m, the matrix G_jk=ipv_jT^n_j+n_kv_k is positive semidefinite. Equivalently, ∑_j,koverlinec_jc_k ipv_jT^n_j+n_kv_k ≥0 for every c∈ C^m.

    Exact mathematical passage
    n_1,\ldots,n_m
\mathcal N_EUse in source · 5 passages

Search aliases: N_E mathcal

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  • Use in source · Read passage · 03_supplement_05.tex, line 3

    The precise finite channel statement. Let H= C^n be a finite coordinate space and let P=P^*=P^2. A matrix is code supported when Pρ P=ρ. For a finite family of square matrices E_a, put N_E(ρ)=∑_a E_aρ E_a^*. The input channel normalization is the actual matrix identity ∑_a E_a^*E_a=I. A finite Kraus recovery has the form R(σ)=∑_r R_rσ R_r^*, with ∑_rR_r^*R_r=I. This representation, together with the checked amplification results, provides complete positivity and trace preservation on the entire …

    Exact mathematical passage
    
    \mathcal N_E(\rho)=\sum_a E_a\rho E_a^*.
    
n_jUse in source · 6 passages

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  • Use in source · monograph_atlas.tex, line 716

    xponential rate needs a common positive lower bound on the gap. Ground multiplicity does not cause a problem: P_0 selects the entire eigenspace at the minimum energy. For a Hamiltonian whose minimum is E_0≠0, the normalized transfer is e^-t(H-E_0I) before taking the limit. headPositivity is retained at several Euclidean times For arbitrary vectors u_j and nonnegative integer times n_j, the reflected kernel obeys ∑_j,k⟨ u_j,T^n_j+n_ku_k⟩ = ∑_jT^n_ju_j ^2. This is a finite Gram factorization. The …

    Exact mathematical passage
    n_j
n_kUse in source · 6 passages

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  • Use in source · monograph_atlas.tex, line 717

    tive lower bound on the gap. Ground multiplicity does not cause a problem: P_0 selects the entire eigenspace at the minimum energy. For a Hamiltonian whose minimum is E_0≠0, the normalized transfer is e^-t(H-E_0I) before taking the limit. headPositivity is retained at several Euclidean times For arbitrary vectors u_j and nonnegative integer times n_j, the reflected kernel obeys ∑_j,k⟨ u_j,T^n_j+n_ku_k⟩ = ∑_jT^n_ju_j ^2. This is a finite Gram factorization. The retained run checks the integer sem…

    Exact mathematical passage
    
    \sum_{j,k}\langle u_j,T^{n_j+n_k}u_k\rangle
    =\left\|\sum_jT^{n_j}u_j\right\|^2.
    
n_mUse in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 1875

    [Finite reflection positivity] For vectors v_1,…,v_m∈ H and nonnegative integers n_1,…,n_m, the matrix G_jk=ipv_jT^n_j+n_kv_k is positive semidefinite. Equivalently, ∑_j,koverlinec_jc_k ipv_jT^n_j+n_kv_k ≥0 for every c∈ C^m.

    Exact mathematical passage
    n_1,\ldots,n_m
N_\varepsilonUse in source · 5 passages

Search aliases: N_ε varepsilon

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  • Use in source · monograph_atlas.tex, line 738

    · 25/16 · 20 · 8/5 These are unnormalized traces. Normalizing by N changes Z_N but leaves the logarithmic derivative at that fixed grid unchanged. xfigheat_limits headThe theorem uses two separate choices For each ε>0, first choose a fixed positive time t_ε so that the continuum torus dimension differs from one by less than ε/2. Then choose N_ε so that every N≥ N_ε differs from that continuum value by less than ε/2 at the same time. This proves one controlled intermediate time for all sufficient…

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    N_\varepsilon
\NNUse in source · 3 passages

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  • Use in source · monograph_atlas.tex, line 769

    a bounded Hamiltonian limitEXACT EMBEDDINGS AND A SUMMABLE TAILTraditional edition: Theorem II.13.2, Theorem II.13.4, Corollary II.13.5. For the exact route, let HH_n= C^n with coordinate inclusions and H_n=diag(0,1,1/2,…,1/(n-1)), H_1=(0). The old energies are retained at every level, H_n+1R_n=R_nH_n, and normH_n≤1. On the Hilbert space of the direct limit ℓ^2( N_0), the diagonal sequence defines a bounded self-adjoint H_∞. Projectors onto even addresses also intertwine and give a fixed complet…

    Exact mathematical passage
    \ell^2(\NN_0)
\NN_0Use in source · 1 passage

Search aliases: NN_0 N_0 NN mathbb

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  • Use in source · monograph_atlas.tex, line 769

    a bounded Hamiltonian limitEXACT EMBEDDINGS AND A SUMMABLE TAILTraditional edition: Theorem II.13.2, Theorem II.13.4, Corollary II.13.5. For the exact route, let HH_n= C^n with coordinate inclusions and H_n=diag(0,1,1/2,…,1/(n-1)), H_1=(0). The old energies are retained at every level, H_n+1R_n=R_nH_n, and normH_n≤1. On the Hilbert space of the direct limit ℓ^2( N_0), the diagonal sequence defines a bounded self-adjoint H_∞. Projectors onto even addresses also intertwine and give a fixed complet…

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    \ell^2(\NN_0)
OUse in source · 10 passages

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  • Use in source · monograph_atlas.tex, line 126

    vpage8Track the Bell state through the circuitINTERMEDIATE PACKETS ARE NOT FINAL PACKETSTraditional edition: Theorem II.4.1, Example II.4.6. The input is ket00. First apply a Hadamard to the first qubit, then a controlled flip: ket00 xmapstoH_rm Had⊗ I fracket00+ket10sqrt2 xmapstorm CNOT fracket00+ket11sqrt2. The displayed columns keep amplitudes, including their normalization, at every step. The middle vector occupies both parity packets. The final vector occupies only the even packet. vfigbell…

    Exact mathematical passage
    
    \ket{00}\ \xmapsto{H_{\rm Had}\otimes I}\
    \frac{\ket{00}+\ket{10}}{\sqrt2}
    \ \xmapsto{\rm CNOT}\
    \frac{\ket{00}+\ket{11}}{\sqrt2}.
    
\mathcal OUse in source · 4 passages

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  • Use in source · Read passage · 03_supplement_03.tex, line 3

    Actual orbits and sharp seed counts. Let C∈ M_d× m( C) be the coefficient matrix of one seed. Define its orbit by actual matrix multiplication: O(C)={AC:A∈ M_d( C)}. This set is already a linear subspace. The source proves that it equals the linear span of the orbit before computing its dimension.

    Exact mathematical passage
    
    \mathcal O(C)=\{AC:A\in M_d(\C)\}.
    
oUse in source · 19 passages

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  • Use in source · monograph_atlas.tex, line 109

    vpage7A coarse packet can still contain coherenceTENSOR REFINEMENT BY TOTAL PARITYTraditional edition: Theorem II.3.7, Corollary II.3.8. For three qubits, the eight fine projectors are P_a=ket abra a. Grouping addresses according to the parity of their Hamming weight gives P_rm even=P_000+P_011+P_101+P_110 =fracI+Z⊗ Z⊗ Z2, P_rm odd=I-P_rm even. This is a sum of subspaces, not an averaging of their coordinates. The rank-four even packet retains all complex amplitudes on its four children. vfigpar…

    Exact mathematical passage
    
    P_{\rm even}=P_{000}+P_{011}+P_{101}+P_{110}
    =\frac{I+Z\otimes Z\otimes Z}{2},
    \qquad P_{\rm odd}=I-P_{\rm even}.
    
O_1Use in source · 1 passage

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  • Use in source · Read passage · 01_finite_core.tex, line 58

    The generated state space is H(ψ_0; O) = span { O_r⋯ O_1ψ_0: O_j∈ O, r≥0 }. The quantum seed is cyclic for the grammar when H(ψ_0; O)= H. This is a statement about the pair (ψ_0, O), not about the vector alone. A state may be cyclic for the full matrix algebra and noncyclic for a restricted physical gate set.

    Exact mathematical passage
    
    \cH(\psi_0;\cO)
    =
    \operatorname{span}
    \left\{
    O_r\cdots O_1\psi_0:
    O_j\in\cO,
    \ r\ge0
    \right\}.
    
\mathcal O_AUse in source · 1 passage

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  • Use in source · Read passage · 03_supplement_03.tex, line 81

    Full support is expressed as surjectivity of the reduced matrix's linear map. Assuming d_A>0, the checked equivalence is O_A(ψ)= H_A⊗ H_B Longleftrightarrow Ranρ_B= H_B. Normalization of ψ is unnecessary for these dimension and support statements. The zero state has rank 0 because its decomposition needs no product terms.

    Exact mathematical passage
    
    \boxed{\mathcal O_A(\psi)=\mathcal H_A\otimes\mathcal H_B
    \quad\Longleftrightarrow\quad \Ran\rho_B=\mathcal H_B.}
    
O_jUse in source · 1 passage

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  • Use in source · Read passage · 01_finite_core.tex, line 58

    The generated state space is H(ψ_0; O) = span { O_r⋯ O_1ψ_0: O_j∈ O, r≥0 }. The quantum seed is cyclic for the grammar when H(ψ_0; O)= H. This is a statement about the pair (ψ_0, O), not about the vector alone. A state may be cyclic for the full matrix algebra and noncyclic for a restricted physical gate set.

    Exact mathematical passage
    
    \cH(\psi_0;\cO)
    =
    \operatorname{span}
    \left\{
    O_r\cdots O_1\psi_0:
    O_j\in\cO,
    \ r\ge0
    \right\}.
    
O_rUse in source · 1 passage

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  • Use in source · Read passage · 01_finite_core.tex, line 58

    The generated state space is H(ψ_0; O) = span { O_r⋯ O_1ψ_0: O_j∈ O, r≥0 }. The quantum seed is cyclic for the grammar when H(ψ_0; O)= H. This is a statement about the pair (ψ_0, O), not about the vector alone. A state may be cyclic for the full matrix algebra and noncyclic for a restricted physical gate set.

    Exact mathematical passage
    
    \cH(\psi_0;\cO)
    =
    \operatorname{span}
    \left\{
    O_r\cdots O_1\psi_0:
    O_j\in\cO,
    \ r\ge0
    \right\}.
    
\mathrm{odd}Use in source · 3 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 228

    For parity, S=Z^⊗ n, P_even=fracI+S2, P_odd=fracI-S2.

    Exact mathematical passage
    
    S=Z^{\otimes n},
    \qquad
    P_{\mathrm{even}}=\frac{I+S}{2},
    \qquad
    P_{\mathrm{odd}}=\frac{I-S}{2}.
    
\overline pUse in source · 1 passage

Search aliases: overline p overline

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  • Use in source · Read passage · 03_supplement_05.tex, line 98

    Rank-one rigidity of the corrected channel. The module tests the map equality on actual matrix units and flattens each A_ra into a row. If X is the matrix of those rows and p is the vector of entries of P, the resulting Gram identity is X^*X=overline p p^ T. The checked rank-one Gram lemma proves that every row of X is proportional to p. For nonzero p, a nonzero coordinate is selected and a test vector supported on two coordinates is placed in the null space of the Gram matrix. The implication X…

    Exact mathematical passage
    
    X^*X=\overline p\,p^{\mathsf T}.
    
\overline UUse in source · 4 passages

Search aliases: overline U overline

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  • Use in source · Read passage · 02_strengthened.tex, line 37

    form a complete orthogonal packet system on Hilbert Schmidt operator space. Dephasing is the diagonal projection. Every channel has input and output superblocks, with the same composition law as ordinary matrix blocks. A covariant channel preserves the isotypic packets of the conjugation action. In the cyclic case these are coherence orders. The Choi matrix carries the equivalent symmetry under U⊗overline U.

    Exact mathematical passage
    U\otimes\overline U
\overline vUse in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 688

    ts memory kernel is K(t)=frac925e^- i t+frac1625e^-2 i t, K(0)=1. Each oscillatory coefficient is positive although K(t) need not be real or pointwise nonnegative. At t=π/2, it equals -16/25-9 i/25. xfigmemory_positive headPositive definite means a matrix test at arbitrary times For retained scalars v_j and real times t_j, the structural identity is ∑_j,koverline v_jK(t_j-t_k)v_k = ∑_k e^ i t_kDB^*v_k ^2≥0. The exact worked check specializes to t=(0,π/2,π) and v=(1,2,-1). Its phases lie in QQ( i…

    Exact mathematical passage
    
    \sum_{j,k}\overline v_jK(t_j-t_k)v_k
    =\left\|\sum_k e^{\ii t_kD}B^*v_k\right\|^2\geq0.
    
\overline v_jUse in source · 1 passage

Search aliases: overline v_j overline

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  • Use in source · monograph_atlas.tex, line 688

    ts memory kernel is K(t)=frac925e^- i t+frac1625e^-2 i t, K(0)=1. Each oscillatory coefficient is positive although K(t) need not be real or pointwise nonnegative. At t=π/2, it equals -16/25-9 i/25. xfigmemory_positive headPositive definite means a matrix test at arbitrary times For retained scalars v_j and real times t_j, the structural identity is ∑_j,koverline v_jK(t_j-t_k)v_k = ∑_k e^ i t_kDB^*v_k ^2≥0. The exact worked check specializes to t=(0,π/2,π) and v=(1,2,-1). Its phases lie in QQ( i…

    Exact mathematical passage
    
    \sum_{j,k}\overline v_jK(t_j-t_k)v_k
    =\left\|\sum_k e^{\ii t_kD}B^*v_k\right\|^2\geq0.
    
\overline zUse in source · 2 passages

Search aliases: overline z overline

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  • Use in source · Read passage · 02_strengthened.tex, line 1577

    [Upper half plane sign] If Imz>0, then ImΣ(z) = -(Imz) B(z-D)^-1(overline z-D)^-1B^* ≤0. Thus -Σ is an operator valued Herglotz function.

    Exact mathematical passage
    
    \operatorname{Im}\Sigma(z)
    =
    -(\operatorname{Im}z)
    B(z-D)^{-1}(\overline z-D)^{-1}B^*
    \leq0.
    
\overline{c_b}Use in source · 1 passage

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  • Use in source · Read passage · 03_supplement_05.tex, line 175

    For E(c)=∑_a c_aE_a, finite-sum expansion gives R(E(c)ρ E(c)^*) =(∑_a,bc_aoverlinec_bC_ba)ρ =(c^*Cc)ρ. The formula with a double sum is the literal checked conclusion. The final notation as a quadratic form follows by renaming finite indices. It is not restricted to orthogonal errors or real coefficients.

    Exact mathematical passage
    
    \mathcal R\bigl(E(c)\rho E(c)^*\bigr)
    =\left(\sum_{a,b}c_a\overline{c_b}C_{ba}\right)\rho
    =(c^*Cc)\rho.
    
\overline{c_j}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 1880

    [Finite reflection positivity] For vectors v_1,…,v_m∈ H and nonnegative integers n_1,…,n_m, the matrix G_jk=ipv_jT^n_j+n_kv_k is positive semidefinite. Equivalently, ∑_j,koverlinec_jc_k ipv_jT^n_j+n_kv_k ≥0 for every c∈ C^m.

    Exact mathematical passage
    
    \sum_{j,k}\overline{c_j}c_k
    \ip{v_j}{T^{n_j+n_k}v_k}
    \geq0
    
\overline{d_{ja}}Use in source · 1 passage

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  • Use in source · Read passage · 01_finite_core.tex, line 833

    he left is a sum of nonnegative squared absolute values and equals zero. Each L_jψ therefore lies in the span of ψ. A linear operator that preserves every line in C is scalar there: apply it to two independent vectors and their sum. The one-dimensional case is immediate, and the claim is vacuous for the zero code. Consequently K_jE_aP=d_jaP. Recovery completeness now gives PE_a^*E_bP · =∑_j (K_jE_aP)^*(K_jE_bP) · =(∑_joverlined_jad_jb)P. The coefficients form a Gram matrix, hence are positive se…

    Exact mathematical passage
    
    \begin{aligned}
    PE_a^*E_bP
    &=\sum_j (K_jE_aP)^*(K_jE_bP)\\
    &=\left(\sum_j\overline{d_{ja}}d_{jb}\right)P.
    \end{aligned}
    
\overline{U(g)}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 1146

    [Choi symmetry criterion] Let U:G→ U( H) be a finite group representation. A channel Φ is covariant, Φ(U(g)XU(g)^*) = U(g)Φ(X)U(g)^*, if and only if (U(g)⊗overlineU(g)) J(Φ) (U(g)^*⊗ U(g)^ T) = J(Φ) for every g∈ G.

    Exact mathematical passage
    
    \bigl(U(g)\otimes\overline{U(g)}\bigr)
    J(\Phi)
    \bigl(U(g)^*\otimes U(g)^{\mathsf T}\bigr)
    =
    J(\Phi)
    
\overline{W_{ja}}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 1323

    [Orthogonal syndrome construction] Assume the Knill Laflamme identities. Then the coefficient matrix c is positive semidefinite. Choose a unitary matrix W such that WcW^*=diag(λ_1,…,λ_r), λ_j≥0, and define F_j=∑_aoverlineW_jaE_a. For every j with λ_j>0, the operator V_j=λ_j^-1/2F_jP is an isometry from the code into H. Its range projector Q_j=V_jV_j^* is a syndrome packet, and the nonzero Q_j are pairwise orthogonal.

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    F_j=\sum_a\overline{W_{ja}}E_a.
    
\overline{z_a}Use in source · 1 passage

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  • Use in source · Read passage · 03_supplement_04.tex, line 131

    identity is R(V_aρ V_b^*)=δ_abρ. Consequently normalized mixtures satisfy R (∑_ap_aV_aρ V_a^*)=ρ when ∑_ap_a=1. The identity is algebraic and is proved for complex weights. Physical mixtures use the nonnegative real case. For a coherent error E_z=∑_a z_aV_a, the calculation of the cross terms yields R(E_zρ E_z^*)=(∑_a z_aoverlinez_a)ρ. Thus the same map also corrects normalized coherent superpositions. This construction supplies the recovery stage used in the full Knill--Laflamme proof that foll…

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    \mathcal R(E_z\rho E_z^*)=\left(\sum_a z_a\overline{z_a}\right)\rho.
    
\overline{z_{ra}}Use in source · 1 passage

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  • Use in source · Read passage · 03_supplement_05.tex, line 111

    Trace-preserving recovery supplies the original Gram data. Let Z_ra=z_ra. The recovery normalization gives PE_a^*E_bP · =PE_a^*(∑_rR_r^*R_r)E_bP · =∑_r(R_rE_aP)^*(R_rE_bP) · =(∑_roverlinez_raz_rb)P =(Z^*Z)_abP. Thus C=Z^*Z is positive semidefinite and satisfies the required compressed identities. The theorem pathgram_of_recovery implements this calculation with the original error and recovery matrices.

    Exact mathematical passage
    
    PE_a^*E_bP
    &=PE_a^*\Bigl(\sum_rR_r^*R_r\Bigr)E_bP\\
    &=\sum_r(R_rE_aP)^*(R_rE_bP)\\
    &=\Bigl(\sum_r\overline{z_{ra}}z_{rb}\Bigr)P
    =(Z^*Z)_{ab}P.
    
\overline{\chi(r)}Use in source · 1 passage

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  • Use in source · Read passage · 03_supplement_03.tex, line 126

    Orthogonality of the projectors. Unitarity supplies ρ(r)^*=ρ(-r), while the character obeys overlineχ(r)=χ(-r). Reindexing r↦-r proves P_j^*=P_j. The final concrete matrix theorem includes Hermiticity together with multiplication, completeness, and eigenaction. Together these identities establish orthogonal spectral packets.

    Exact mathematical passage
    \overline{\chi(r)}=\chi(-r)
\overline{\chi_\lambda(g)}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 207

    [Finite group isotypic projectors] The operators P_λ = fracd_λabsG ∑_g∈ G overlineχ_λ(g)U(g) are orthogonal projectors. They satisfy P_λ P_μ=δ_λμP_λ, ∑_λ∈widehat GP_λ=I_ H. The range of P_λ is the λ isotypic component of H.

    Exact mathematical passage
    
    P_\lambda
    =
    \frac{d_\lambda}{\abs{G}}
    \sum_{g\in G}
    \overline{\chi_\lambda(g)}U(g)
    
pUse in source · 21 passages

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  • Use in source · monograph_atlas.tex, line 299

    g Every effect in the computational basis E_a=ket abra a has the same expectation on both matrices, namely 1/2 at 00 and 11 and zero elsewhere. These measurements read only the diagonal. They cannot distinguish the pure Bell state from this incoherent mixture. headA measurement that resolves the difference Use the valid two-outcome measurement with effects E=ρ and I-E. Then Tr(Eρ)=1, Tr (E D_rm computational(ρ))=frac12. The effect itself is not diagonal in the fine computational packets. It comp…

    Exact mathematical passage
    
    \Tr(E\rho)=1,\qquad
    \Tr\!\left(E D_{\rm computational}(\rho)\right)=\frac12.
    
p^{\mathsf T}Use in source · 1 passage

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  • Use in source · Read passage · 03_supplement_05.tex, line 98

    Rank-one rigidity of the corrected channel. The module tests the map equality on actual matrix units and flattens each A_ra into a row. If X is the matrix of those rows and p is the vector of entries of P, the resulting Gram identity is X^*X=overline p p^ T. The checked rank-one Gram lemma proves that every row of X is proportional to p. For nonzero p, a nonzero coordinate is selected and a test vector supported on two coordinates is placed in the null space of the Gram matrix. The implication X…

    Exact mathematical passage
    
    X^*X=\overline p\,p^{\mathsf T}.
    
P^{(1)}_{j_1}Use in source · 2 passages

Search aliases: P^(1)_j_1

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  • Use in source · Read passage · 01_finite_core.tex, line 239

    Fix N≥1. Suppose every factor a has a complete orthogonal family P^(a)_0,…,P^(a)_N-1. The fine tensor packets are P_ j^fine = P^(1)_j_1⊗⋯⊗ P^(m)_j_m.

    Exact mathematical passage
    
    P_{\mathbf j}^{\mathrm{fine}}
    =
    P^{(1)}_{j_1}\otimes\cdots\otimes P^{(m)}_{j_m}.
    
P^{(a)}_0Use in source · 1 passage

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  • Use in source · Read passage · 01_finite_core.tex, line 238

    Fix N≥1. Suppose every factor a has a complete orthogonal family P^(a)_0,…,P^(a)_N-1. The fine tensor packets are P_ j^fine = P^(1)_j_1⊗⋯⊗ P^(m)_j_m.

    Exact mathematical passage
    P^{(a)}_0,\ldots,P^{(a)}_{N-1}
P^{(a)}_{N-1}Use in source · 1 passage

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  • Use in source · Read passage · 01_finite_core.tex, line 238

    Fix N≥1. Suppose every factor a has a complete orthogonal family P^(a)_0,…,P^(a)_N-1. The fine tensor packets are P_ j^fine = P^(1)_j_1⊗⋯⊗ P^(m)_j_m.

    Exact mathematical passage
    P^{(a)}_0,\ldots,P^{(a)}_{N-1}
P^{(i)}_{a_i}Use in source · 1 passage

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  • Use in source · Read passage · 03_supplement_02.tex, line 54

    Suppose N>0 and each factor has a complete orthogonal self-adjoint projector family (P^(i)_j)_j∈ Z/N Z. For a fine address a:F→ Z/N Z, set Q_a= T(i↦ P^(i)_a_i), C_r=∑_∑_i a_i=rQ_a.

    Exact mathematical passage
    
     Q_a=\mathsf T\bigl(i\mapsto P^{(i)}_{a_i}\bigr),
     \qquad
     C_r=\sum_{\sum_i a_i=r}Q_a.
    
P^{(i)}_jUse in source · 2 passages

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  • Use in source · Read passage · 03_supplement_02.tex, line 53

    Suppose N>0 and each factor has a complete orthogonal self-adjoint projector family (P^(i)_j)_j∈ Z/N Z. For a fine address a:F→ Z/N Z, set Q_a= T(i↦ P^(i)_a_i), C_r=∑_∑_i a_i=rQ_a.

    Exact mathematical passage
    (P^{(i)}_j)_{j\in\mathbb Z/N\mathbb Z}
P^{(m)}_{j_m}Use in source · 2 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 239

    Fix N≥1. Suppose every factor a has a complete orthogonal family P^(a)_0,…,P^(a)_N-1. The fine tensor packets are P_ j^fine = P^(1)_j_1⊗⋯⊗ P^(m)_j_m.

    Exact mathematical passage
    
    P_{\mathbf j}^{\mathrm{fine}}
    =
    P^{(1)}_{j_1}\otimes\cdots\otimes P^{(m)}_{j_m}.
    
P^*Use in source · 4 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 792

    Let P=P^*=P^2 project onto a code space C⊂ H, and let E_1,…,E_r be a finite family of complex error matrices. Neither a nonzero code nor channel normalization is assumed unless stated. The operators P E_a^*E_bP are the obstruction packets on the code. If they retain information about the logical state beyond one scalar multiple of P, the environment can distinguish logical states and exact correction is impossible.

    Exact mathematical passage
    P=P^*=P^2
P_{\mathbf j}^{\mathrm{fine}}Use in source · 1 passage

Search aliases: P_ j^fine mathbf mathrm

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  • Use in source · Read passage · 01_finite_core.tex, line 239

    Fix N≥1. Suppose every factor a has a complete orthogonal family P^(a)_0,…,P^(a)_N-1. The fine tensor packets are P_ j^fine = P^(1)_j_1⊗⋯⊗ P^(m)_j_m.

    Exact mathematical passage
    
    P_{\mathbf j}^{\mathrm{fine}}
    =
    P^{(1)}_{j_1}\otimes\cdots\otimes P^{(m)}_{j_m}.
    
P_{\bm j}^{\rm fine}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 343

    Suppose the ath tensor factor carries a cyclic packet family (P_j^(a))_j∈ Z/N Z. The fine tensor packets are P_ j^rm fine = P_j_1^(1)⊗⋯⊗ P_j_m^(m).

    Exact mathematical passage
    
    P_{\bm j}^{\rm fine}
    =
    P_{j_1}^{(1)}\otimes\cdots\otimes P_{j_m}^{(m)}.
    
P_{000}Use in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 109

    vpage7A coarse packet can still contain coherenceTENSOR REFINEMENT BY TOTAL PARITYTraditional edition: Theorem II.3.7, Corollary II.3.8. For three qubits, the eight fine projectors are P_a=ket abra a. Grouping addresses according to the parity of their Hamming weight gives P_rm even=P_000+P_011+P_101+P_110 =fracI+Z⊗ Z⊗ Z2, P_rm odd=I-P_rm even. This is a sum of subspaces, not an averaging of their coordinates. The rank-four even packet retains all complex amplitudes on its four children. vfigpar…

    Exact mathematical passage
    
    P_{\rm even}=P_{000}+P_{011}+P_{101}+P_{110}
    =\frac{I+Z\otimes Z\otimes Z}{2},
    \qquad P_{\rm odd}=I-P_{\rm even}.
    
P_{011}Use in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 109

    vpage7A coarse packet can still contain coherenceTENSOR REFINEMENT BY TOTAL PARITYTraditional edition: Theorem II.3.7, Corollary II.3.8. For three qubits, the eight fine projectors are P_a=ket abra a. Grouping addresses according to the parity of their Hamming weight gives P_rm even=P_000+P_011+P_101+P_110 =fracI+Z⊗ Z⊗ Z2, P_rm odd=I-P_rm even. This is a sum of subspaces, not an averaging of their coordinates. The rank-four even packet retains all complex amplitudes on its four children. vfigpar…

    Exact mathematical passage
    
    P_{\rm even}=P_{000}+P_{011}+P_{101}+P_{110}
    =\frac{I+Z\otimes Z\otimes Z}{2},
    \qquad P_{\rm odd}=I-P_{\rm even}.
    
P_1Use in source · 3 passages

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  • Use in source · monograph_atlas.tex, line 555

    vpage30Rotate whole packets by a polar factorAN EXACT LOCAL CHART AND ITS FAILURETraditional edition: Theorem II.6.5, Theorem II.6.6. On HH= C^2, put P_0=diag(1,0), P_1=I-P_0, and R=mat3/5 · -4/5

    Exact mathematical passage
    P_1=I-P_0
P_{101}Use in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 109

    vpage7A coarse packet can still contain coherenceTENSOR REFINEMENT BY TOTAL PARITYTraditional edition: Theorem II.3.7, Corollary II.3.8. For three qubits, the eight fine projectors are P_a=ket abra a. Grouping addresses according to the parity of their Hamming weight gives P_rm even=P_000+P_011+P_101+P_110 =fracI+Z⊗ Z⊗ Z2, P_rm odd=I-P_rm even. This is a sum of subspaces, not an averaging of their coordinates. The rank-four even packet retains all complex amplitudes on its four children. vfigpar…

    Exact mathematical passage
    
    P_{\rm even}=P_{000}+P_{011}+P_{101}+P_{110}
    =\frac{I+Z\otimes Z\otimes Z}{2},
    \qquad P_{\rm odd}=I-P_{\rm even}.
    
P_{110}Use in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 109

    vpage7A coarse packet can still contain coherenceTENSOR REFINEMENT BY TOTAL PARITYTraditional edition: Theorem II.3.7, Corollary II.3.8. For three qubits, the eight fine projectors are P_a=ket abra a. Grouping addresses according to the parity of their Hamming weight gives P_rm even=P_000+P_011+P_101+P_110 =fracI+Z⊗ Z⊗ Z2, P_rm odd=I-P_rm even. This is a sum of subspaces, not an averaging of their coordinates. The rank-four even packet retains all complex amplitudes on its four children. vfigpar…

    Exact mathematical passage
    
    P_{\rm even}=P_{000}+P_{011}+P_{101}+P_{110}
    =\frac{I+Z\otimes Z\otimes Z}{2},
    \qquad P_{\rm odd}=I-P_{\rm even}.
    
P_2Use in source · 1 passage

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  • Use in source · cyclic_four.tex, line 49

    ll] at (8.05,3.8) S v_0=1v_0; node[font=small,align=center,font=small] at (11.85,3.8) P_0=v_0v_0^*; node[font=small,align=center,font=small] at (8.05,2.95) S v_1=iv_1; node[font=small,align=center,font=small] at (11.85,2.95) P_1=v_1v_1^*; node[font=small,align=center,font=small] at (8.05,2.1) S v_2=-1v_2; node[font=small,align=center,font=small] at (11.85,2.1) P_2=v_2v_2^*; node[font=small,align=center,font=small] at (8.05,1.25) S v_3=- iv_3; node[font=small,align=center,font=small] at (11.85,1.…

    Exact mathematical passage
    P_2=v_2v_2^*
P_3Use in source · 1 passage

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  • Use in source · cyclic_four.tex, line 51

    at (8.05,2.95) S v_1=iv_1; node[font=small,align=center,font=small] at (11.85,2.95) P_1=v_1v_1^*; node[font=small,align=center,font=small] at (8.05,2.1) S v_2=-1v_2; node[font=small,align=center,font=small] at (11.85,2.1) P_2=v_2v_2^*; node[font=small,align=center,font=small] at (8.05,1.25) S v_3=- iv_3; node[font=small,align=center,font=small] at (11.85,1.25) P_3=v_3v_3^*; node[font=small,align=center,font=scriptsize] at (8.8,0.12) Each column has four entries of magnitude 1/2.;

    Exact mathematical passage
    P_3=v_3v_3^*
p_aUse in source · 1 passage

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  • Use in source · Read passage · 03_supplement_04.tex, line 126

    Exact correction, including coherent errors. For every operator supported on the code, Pρ P=ρ, the central identity is R(V_aρ V_b^*)=δ_abρ. Consequently normalized mixtures satisfy R (∑_ap_aV_aρ V_a^*)=ρ when ∑_ap_a=1. The identity is algebraic and is proved for complex weights. Physical mixtures use the nonnegative real case. For a coherent error E_z=∑_a z_aV_a, the calculation of the cross terms yields R(E_zρ E_z^*)=(∑_a z_aoverlinez_a)ρ. Thus the same map also corrects normalized coherent sup…

    Exact mathematical passage
    
    \mathcal R\!\left(\sum_ap_aV_a\rho V_a^*\right)=\rho
    \quad\text{when}\quad\sum_ap_a=1.
    
P_a^*Use in source · 3 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 1013

    The projectors P_a form a Kraus family because ∑_aP_a^*P_a=I. Thus the map is completely positive and trace preserving. It is unital for the same reason. Orthogonality and idempotence follow from [source reference]. Its range is the sum of the diagonal operator packets. This is exactly the commutant of the projector family.

    Exact mathematical passage
    \sum_aP_a^*P_a=I
P_a^2Use in source · 2 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 541

    Differentiating P_a^2=P_a gives dot P_aP_a+P_adot P_a=dot P_a. Summing over a and using ∑_adot P_a=0 yields ∑_aP_adot P_a=-∑_adot P_aP_a, which proves both displayed formulas for C and its skew-Hermiticity.

    Exact mathematical passage
    P_a^2=P_a
P_{a_0}Use in source · 4 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 390

    [Exact circuit path expansion] For source packet a_0 and target packet a_m, P_a_mUP_a_0 = ∑_a_1,…,a_m-1 P_a_mU_mP_a_m-1 ⋯ P_a_1U_1P_a_0. Summing over a_0 and a_m reconstructs U.

    Exact mathematical passage
    
    P_{a_m}UP_{a_0}
    =
    \sum_{a_1,\ldots,a_{m-1}}
    P_{a_m}U_mP_{a_{m-1}}
    \cdots
    P_{a_1}U_1P_{a_0}.
    
P_{a_1}Use in source · 3 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 390

    [Exact circuit path expansion] For source packet a_0 and target packet a_m, P_a_mUP_a_0 = ∑_a_1,…,a_m-1 P_a_mU_mP_a_m-1 ⋯ P_a_1U_1P_a_0. Summing over a_0 and a_m reconstructs U.

    Exact mathematical passage
    
    P_{a_m}UP_{a_0}
    =
    \sum_{a_1,\ldots,a_{m-1}}
    P_{a_m}U_mP_{a_{m-1}}
    \cdots
    P_{a_1}U_1P_{a_0}.
    
P_{a_m}Use in source · 3 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 390

    [Exact circuit path expansion] For source packet a_0 and target packet a_m, P_a_mUP_a_0 = ∑_a_1,…,a_m-1 P_a_mU_mP_a_m-1 ⋯ P_a_1U_1P_a_0. Summing over a_0 and a_m reconstructs U.

    Exact mathematical passage
    
    P_{a_m}UP_{a_0}
    =
    \sum_{a_1,\ldots,a_{m-1}}
    P_{a_m}U_mP_{a_{m-1}}
    \cdots
    P_{a_1}U_1P_{a_0}.
    
P_{a_{m-1}}Use in source · 3 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 390

    [Exact circuit path expansion] For source packet a_0 and target packet a_m, P_a_mUP_a_0 = ∑_a_1,…,a_m-1 P_a_mU_mP_a_m-1 ⋯ P_a_1U_1P_a_0. Summing over a_0 and a_m reconstructs U.

    Exact mathematical passage
    
    P_{a_m}UP_{a_0}
    =
    \sum_{a_1,\ldots,a_{m-1}}
    P_{a_m}U_mP_{a_{m-1}}
    \cdots
    P_{a_1}U_1P_{a_0}.
    
P_b^2Use in source · 1 passage

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  • Use in source · Read passage · 03_supplement_01.tex, line 41

    UU^*=1 · Longrightarrow ∑_aU_ba(U_da)^*=δ_bdP_b. For the first law, expand each corner, collapse P_b^2 and sum: ∑_bP_aU^*P_bUP_c =P_aU^*(∑_bP_b)UP_c=P_aP_c. The second law follows by the analogous calculation and has its own formal proof. For complex matrices, the adjoint is the conjugate transpose. The order of the operator products is preserved throughout.

    Exact mathematical passage
    P_b^2
P_cUse in source · 5 passages

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  • Use in source · monograph_atlas.tex, line 136

    le vector occupies both parity packets. The final vector occupies only the even packet. vfigbell_circuit headHow the exact path expansion works Insert P_rm even+P_rm odd=I between the two gates. Each summand records a particular intermediate packet, while the boundary projectors select its input and output packets. Summing all terms recovers the original 4×4 circuit matrix: ∑_a,b,cP_b CNOT P_a (H_rm Had⊗ I)P_c =CNOT(H_rm Had⊗ I). This expansion is an identity even though the intermediate parity …

    Exact mathematical passage
    
    \sum_{a,b,c}P_b\,\mathrm{CNOT}\,P_a
    (H_{\rm Had}\otimes I)P_c
    =\mathrm{CNOT}(H_{\rm Had}\otimes I).
    
P_c^2Use in source · 1 passage

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  • Use in source · Read passage · 03_supplement_01.tex, line 16

    0, · a≠ b, ∑_a∈ IP_a=1. Adjoint conditions are added when needed. For an operator U, define the transfer corner U_ba=P_bUP_a. The target index comes first. Completeness and distributivity give ∑_b,aU_ba=U, (UV)_ba=∑_c U_bcV_ca. The second identity uses P_c^2=P_c when adjacent transfer corners are multiplied.

    Exact mathematical passage
    P_c^2=P_c
P_dUse in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 970

    Idempotence and completeness follow from the projector identities. For Hilbert Schmidt orthogonality, ipP_aXP_bP_cYP_d_HS · = Tr(P_bX^*P_aP_cYP_d) · = δ_acδ_bd Tr(P_bX^*P_aYP_b). Since the packets are orthogonal and sum to the original operator, their squared norms add to its squared norm.

    Exact mathematical passage
    
    \begin{aligned}
    \ip{P_aXP_b}{P_cYP_d}_{\HS}
    &=
    \Tr(P_bX^*P_aP_cYP_d)\\
    &=
    \delta_{ac}\delta_{bd}
    \Tr(P_bX^*P_aYP_b).
    \end{aligned}
    
P_{\mathrm{even}}Use in source · 1 passage

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  • Use in source · Read passage · 01_finite_core.tex, line 228

    For parity, S=Z^⊗ n, P_even=fracI+S2, P_odd=fracI-S2.

    Exact mathematical passage
    
    S=Z^{\otimes n},
    \qquad
    P_{\mathrm{even}}=\frac{I+S}{2},
    \qquad
    P_{\mathrm{odd}}=\frac{I-S}{2}.
    
P_jUse in source · 22 passages

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  • Use in source · monograph_atlas.tex, line 93

    vpage6Four phases resolve a cyclic shiftCHARACTER PROJECTORS YOU CAN MULTIPLYTraditional edition: Corollary II.3.3. On four sites, let Sket k=ketk+1bmod4 and let ω= i. The character projectors are the exact matrices P_j=frac14∑_r=0^3 i^-jrS^r, v_j(k)=frac12 i^-jk, P_j=v_jv_j^*. All entries belong to the Gaussian rationals. Thus no approximation to a root of unity is needed in this model. vfigcyclic_four headReading the columns Each column v_j is a normalized wave around the four sites. Advancing…

    Exact mathematical passage
    
    P_j=\frac14\sum_{r=0}^3\ii^{-jr}S^r,
    \qquad v_j(k)=\frac12\ii^{-jk},\qquad P_j=v_jv_j^*.
    
P_{j+q}Use in source · 3 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 306

    [Charge selection rule] If A has charge q, then P_kAP_j=0 unless k=j+q in Z/N Z. In fact, AP_j=P_j+qAP_j.

    Exact mathematical passage
    
    AP_j=P_{j+q}AP_j.
    
P_j^{(a)}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 339

    Suppose the ath tensor factor carries a cyclic packet family (P_j^(a))_j∈ Z/N Z. The fine tensor packets are P_ j^rm fine = P_j_1^(1)⊗⋯⊗ P_j_m^(m).

    Exact mathematical passage
    
    \bigl(P_j^{(a)}\bigr)_{j\in\ZZ/N\ZZ}.
    
P_j^*Use in source · 2 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 221

    Using S^r+s=S^r+sbmod N and the finite character orthogonality relation, frac1N∑_r=0^N-1ω^(k-j)r=δ_jk, we obtain P_jP_k=δ_jkP_j. Summing over j cancels every term indexed by r≠0 and retains the r=0 term, which proves completeness. Unitarity and the change of residue r↦-r give P_j^*=frac1N∑_r=0^N-1ω^jrS^-r=P_j. Finally, multiplication by S shifts the summation index and contributes the factor ω^j.

    Exact mathematical passage
    
    P_j^*=\frac1N\sum_{r=0}^{N-1}\omega^{jr}S^{-r}=P_j.
    
P_j^2Use in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 102

    Multiplying the actual projectors gives P_jP_k=0 for j≠ k, P_j^2=P_j, and ∑_jP_j=I. In particular, the complete packet tuple (P_jψ)_j retains the original vector exactly. Recording only the four packet norms is a different operation and can discard phase information between packets.

    Exact mathematical passage
    P_j^2=P_j
P_{j_1}^{(1)}Use in source · 2 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 343

    Suppose the ath tensor factor carries a cyclic packet family (P_j^(a))_j∈ Z/N Z. The fine tensor packets are P_ j^rm fine = P_j_1^(1)⊗⋯⊗ P_j_m^(m).

    Exact mathematical passage
    
    P_{\bm j}^{\rm fine}
    =
    P_{j_1}^{(1)}\otimes\cdots\otimes P_{j_m}^{(m)}.
    
P_{j_m}^{(m)}Use in source · 2 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 343

    Suppose the ath tensor factor carries a cyclic packet family (P_j^(a))_j∈ Z/N Z. The fine tensor packets are P_ j^rm fine = P_j_1^(1)⊗⋯⊗ P_j_m^(m).

    Exact mathematical passage
    
    P_{\bm j}^{\rm fine}
    =
    P_{j_1}^{(1)}\otimes\cdots\otimes P_{j_m}^{(m)}.
    
P_kUse in source · 5 passages

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  • Use in source · monograph_atlas.tex, line 102

    Multiplying the actual projectors gives P_jP_k=0 for j≠ k, P_j^2=P_j, and ∑_jP_j=I. In particular, the complete packet tuple (P_jψ)_j retains the original vector exactly. Recording only the four packet norms is a different operation and can discard phase information between packets.

    Exact mathematical passage
    P_jP_k=0
p_kUse in source · 1 passage

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  • Use in source · Read passage · 01_finite_core.tex, line 681

    Let ρ be a density matrix and let {E_k} be a POVM: E_k≥0, ∑_kE_k=I. The outcome probabilities are p_k=Tr(E_kρ).

    Exact mathematical passage
    
    p_k=\Tr(E_k\rho).
    
P_mUse in source · 1 passage

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  • Use in source · Read passage · 01_finite_core.tex, line 509

    Let P_1(t),…,P_m(t) be differentiable on an open real time interval, with P_a(t)^*=P_a(t) and P_aP_b=δ_abP_a, ∑_aP_a=I.

    Exact mathematical passage
    P_1(t),\ldots,P_m(t)
P_nUse in source · 7 passages

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  • Use in source · monograph_atlas.tex, line 795

    nite Gram matrix is a sum of two positive rank-one matrices, and pointwise convergence gives C(j,k)=1+(1/2)^j+k. For times (0,1,2) and coefficients (1,-2,1), ∑_j,kv_jC_n(j,k)v_k=(1-q_n)^4≥0. This exact check illustrates how finite quadratic forms pass positivity to the limit. xfigtrace_topology headOperator norm does not preserve trace in growing rank On ℓ^2, let P_n select the first n coordinates and set A_n=P_n/n. Then normA_n=1/n→0 while Tr A_n=1 for every n. These positive trace-class operat…

    Exact mathematical passage
    P_n
P_{\mathrm{odd}}Use in source · 1 passage

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  • Use in source · Read passage · 01_finite_core.tex, line 228

    For parity, S=Z^⊗ n, P_even=fracI+S2, P_odd=fracI-S2.

    Exact mathematical passage
    
    S=Z^{\otimes n},
    \qquad
    P_{\mathrm{even}}=\frac{I+S}{2},
    \qquad
    P_{\mathrm{odd}}=\frac{I-S}{2}.
    
P_{\phys}Use in source · 6 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 45

    Constraint closure needs a different obstruction. If C_a are self adjoint constraints and P_phys projects onto their common kernel, then P_phys[C_a,C_b]P_phys=0 holds automatically. This compression cannot test closure. The correct finite obstruction is the class of [C_a,C_b] in the quotient of End( H) by the span of the constraints. Vanishing means that the constraint span is closed under commutators.

    Exact mathematical passage
    P_{\phys}
P_r^{\mathrm{coarse}}Use in source · 2 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 247

    [Tensor/polyphase refinement] For each residue r∈ Z/N Z, define P_r^coarse = ∑_j_1+⋯+j_m≡ rpmod N P^(1)_j_1⊗⋯⊗ P^(m)_j_m. Then the P_r^coarse are complete orthogonal projectors, and every coarse packet is the exact sum of its fine descendants.

    Exact mathematical passage
    
    \boxed{
    P_r^{\mathrm{coarse}}
    =
    \sum_{j_1+\cdots+j_m\equiv r\pmod N}
    P^{(1)}_{j_1}\otimes\cdots\otimes P^{(m)}_{j_m}.
    }
    
P_r^{\rm total}Use in source · 2 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 351

    [Tensor charge refinement] For r∈ Z/N Z, define P_r^rm total = ∑_j_1+⋯+j_m=r P_j_1^(1)⊗⋯⊗ P_j_m^(m). Then the P_r^rm total form a complete orthogonal packet system. Every total charge packet is the exact sum of its fine tensor descendants.

    Exact mathematical passage
    
    P_r^{\rm total}
    =
    \sum_{j_1+\cdots+j_m=r}
    P_{j_1}^{(1)}\otimes\cdots\otimes P_{j_m}^{(m)}.
    
P_{\rm even}Use in source · 2 passages

Search aliases: P_rm even rm

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  • Use in source · monograph_atlas.tex, line 109

    vpage7A coarse packet can still contain coherenceTENSOR REFINEMENT BY TOTAL PARITYTraditional edition: Theorem II.3.7, Corollary II.3.8. For three qubits, the eight fine projectors are P_a=ket abra a. Grouping addresses according to the parity of their Hamming weight gives P_rm even=P_000+P_011+P_101+P_110 =fracI+Z⊗ Z⊗ Z2, P_rm odd=I-P_rm even. This is a sum of subspaces, not an averaging of their coordinates. The rank-four even packet retains all complex amplitudes on its four children. vfigpar…

    Exact mathematical passage
    
    P_{\rm even}=P_{000}+P_{011}+P_{101}+P_{110}
    =\frac{I+Z\otimes Z\otimes Z}{2},
    \qquad P_{\rm odd}=I-P_{\rm even}.
    
P_{\rm odd}Use in source · 2 passages

Search aliases: P_rm odd rm

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  • Use in source · monograph_atlas.tex, line 109

    vpage7A coarse packet can still contain coherenceTENSOR REFINEMENT BY TOTAL PARITYTraditional edition: Theorem II.3.7, Corollary II.3.8. For three qubits, the eight fine projectors are P_a=ket abra a. Grouping addresses according to the parity of their Hamming weight gives P_rm even=P_000+P_011+P_101+P_110 =fracI+Z⊗ Z⊗ Z2, P_rm odd=I-P_rm even. This is a sum of subspaces, not an averaging of their coordinates. The rank-four even packet retains all complex amplitudes on its four children. vfigpar…

    Exact mathematical passage
    
    P_{\rm even}=P_{000}+P_{011}+P_{101}+P_{110}
    =\frac{I+Z\otimes Z\otimes Z}{2},
    \qquad P_{\rm odd}=I-P_{\rm even}.
    
P_{\alpha_0}Use in source · 1 passage

Search aliases: P_α_0 alpha

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  • Use in source · Read passage · 01_finite_core.tex, line 283

    [Exact circuit path expansion] For source packet α_0 and target packet α_m, P_α_mUP_α_0 = ∑_α_1,…,α_m-1 P_α_mU_mP_α_m-1 ⋯ P_α_1U_1P_α_0. Summing over the source and target packets reconstructs the complete circuit operator.

    Exact mathematical passage
    
    \boxed{
    P_{\alpha_m}UP_{\alpha_0}
    =
    \sum_{\alpha_1,\ldots,\alpha_{m-1}}
    P_{\alpha_m}U_mP_{\alpha_{m-1}}
    \cdots
    P_{\alpha_1}U_1P_{\alpha_0}.
    }
    
P_{\alpha_1}Use in source · 1 passage

Search aliases: P_α_1 alpha

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  • Use in source · Read passage · 01_finite_core.tex, line 283

    [Exact circuit path expansion] For source packet α_0 and target packet α_m, P_α_mUP_α_0 = ∑_α_1,…,α_m-1 P_α_mU_mP_α_m-1 ⋯ P_α_1U_1P_α_0. Summing over the source and target packets reconstructs the complete circuit operator.

    Exact mathematical passage
    
    \boxed{
    P_{\alpha_m}UP_{\alpha_0}
    =
    \sum_{\alpha_1,\ldots,\alpha_{m-1}}
    P_{\alpha_m}U_mP_{\alpha_{m-1}}
    \cdots
    P_{\alpha_1}U_1P_{\alpha_0}.
    }
    
P_{\alpha_m}Use in source · 1 passage

Search aliases: P_α_m alpha

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  • Use in source · Read passage · 01_finite_core.tex, line 283

    [Exact circuit path expansion] For source packet α_0 and target packet α_m, P_α_mUP_α_0 = ∑_α_1,…,α_m-1 P_α_mU_mP_α_m-1 ⋯ P_α_1U_1P_α_0. Summing over the source and target packets reconstructs the complete circuit operator.

    Exact mathematical passage
    
    \boxed{
    P_{\alpha_m}UP_{\alpha_0}
    =
    \sum_{\alpha_1,\ldots,\alpha_{m-1}}
    P_{\alpha_m}U_mP_{\alpha_{m-1}}
    \cdots
    P_{\alpha_1}U_1P_{\alpha_0}.
    }
    
P_{\alpha_{m-1}}Use in source · 1 passage

Search aliases: P_α_m-1 alpha

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  • Use in source · Read passage · 01_finite_core.tex, line 283

    [Exact circuit path expansion] For source packet α_0 and target packet α_m, P_α_mUP_α_0 = ∑_α_1,…,α_m-1 P_α_mU_mP_α_m-1 ⋯ P_α_1U_1P_α_0. Summing over the source and target packets reconstructs the complete circuit operator.

    Exact mathematical passage
    
    \boxed{
    P_{\alpha_m}UP_{\alpha_0}
    =
    \sum_{\alpha_1,\ldots,\alpha_{m-1}}
    P_{\alpha_m}U_mP_{\alpha_{m-1}}
    \cdots
    P_{\alpha_1}U_1P_{\alpha_0}.
    }
    
P_\gammaUse in source · 2 passages

Search aliases: P_γ gamma

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  • Use in source · Read passage · 01_finite_core.tex, line 319

    Using completeness and unitarity, ∑_β U_βα^*U_βγ = P_α U^*(∑_β P_β)UP_γ = P_α P_γ. For the second identity, sum over the source packets and use unitarity in the reverse order.

    Exact mathematical passage
    
    \sum_\beta U_{\beta\alpha}^*U_{\beta\gamma}
    =
    P_\alpha U^*\left(\sum_\beta P_\beta\right)UP_\gamma
    =
    P_\alpha P_\gamma.
    
P_\deltaUse in source · 1 passage

Search aliases: P_δ delta

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  • Use in source · Read passage · 01_finite_core.tex, line 751

    Packet superoperator blocks are defined by Φ_αβ;γδ(X) = P_α Φ(P_γ XP_δ) P_β. Summing all four packet indices reconstructs Φ(X) exactly.

    Exact mathematical passage
    
    \Phi_{\alpha\beta;\gamma\delta}(X)
    =
    P_\alpha
    \Phi(P_\gamma XP_\delta)
    P_\beta.
    
P_\lambdaUse in source · 5 passages

Search aliases: P_λ lambda

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  • Use in source · monograph_atlas.tex, line 534

    , not unproved continuum claims or a new theorem count. vpage29Nonabelian packets carry multiplicityA SIX-DIMENSIONAL REGULAR REPRESENTATIONTraditional edition: Theorem II.3.1, Theorem II.3.2. Let HH= C[S_3] have the six orthonormal basis vectors ket g, with left action U(h)ket g=kethg. The irreducible characters on the identity, transposition, and three-cycle classes are c|rrr|r · e · (12) · (123) · d_λ trivial · 1 · 1 · 1 · 1 sign · 1 · -1 · 1 · 1 standard · 2 · 0 · -1 · 2 P_λ=fracd_λ6∑_g∈ S_3…

    Exact mathematical passage
    
    \begin{array}{c|rrr|r}
     & e & (12)&(123)&d_\lambda\\\hline
    \text{trivial}&1&1&1&1\\
    \text{sign}&1&-1&1&1\\
    \text{standard}&2&0&-1&2
    \end{array}
    \qquad
    P_\lambda=\frac{d_\lambda}{6}\sum_{g\in S_3}\chi_\lambda(g^{-1})U(g).
    
P_\muUse in source · 1 passage

Search aliases: P_μ mu

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  • Use in source · Read passage · 02_strengthened.tex, line 215

    [Finite group isotypic projectors] The operators P_λ = fracd_λabsG ∑_g∈ G overlineχ_λ(g)U(g) are orthogonal projectors. They satisfy P_λ P_μ=δ_λμP_λ, ∑_λ∈widehat GP_λ=I_ H. The range of P_λ is the λ isotypic component of H.

    Exact mathematical passage
    
    P_\lambda P_\mu=\delta_{\lambda\mu}P_\lambda,
    \qquad
    \sum_{\lambda\in\widehat G}P_\lambda=I_{\Hcal}.
    
P_{\ell+1,a}Use in source · 1 passage

Search aliases: P_ℓ+1,a ell

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  • Use in source · Read passage · 02_strengthened.tex, line 2404

    [Exact packet direct limit] Assume the packet families have one fixed finite address set at every level and each packet address a is compatible in the sense P_ℓ+1,aR_ℓ=R_ℓ P_ℓ,a. Then there is an orthogonal projector P_∞,a on H_∞ satisfying P_∞,aι_ℓ=ι_ℓ P_ℓ,a. Finite completeness and orthogonality pass to the direct limit.

    Exact mathematical passage
    
    P_{\ell+1,a}R_\ell=R_\ell P_{\ell,a}.
    
P_{\ell+1,\beta}Use in source · 1 passage

Search aliases: P_ℓ+1,β ell beta

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  • Use in source · Read passage · 01_finite_core.tex, line 1026

    A coherent refinement should satisfy C_ℓ E_ℓ=I and P_ℓ,α = C_ℓ ( ∑_βsuccαP_ℓ+1,β ) E_ℓ. For an operator D, define the refinement defect Δ_ℓ(D) =C_ℓ D_ℓ+1E_ℓ-D_ℓ. Exact resolution independence is Δ_ℓ(D)=0. When exact equality is too strong, the correct continuum problem is to prove convergence of the resolvents and uniform control of the effective self-energies.

    Exact mathematical passage
    
    \boxed{
    P_{\ell,\alpha}
    =
    C_\ell
    \left(
    \sum_{\beta\succ\alpha}P_{\ell+1,\beta}
    \right)
    E_\ell.
    }
    
P_{\infty,a}Use in source · 2 passages

Search aliases: P_∞,a infty

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  • Use in source · Read passage · 02_strengthened.tex, line 2407

    [Exact packet direct limit] Assume the packet families have one fixed finite address set at every level and each packet address a is compatible in the sense P_ℓ+1,aR_ℓ=R_ℓ P_ℓ,a. Then there is an orthogonal projector P_∞,a on H_∞ satisfying P_∞,aι_ℓ=ι_ℓ P_ℓ,a. Finite completeness and orthogonality pass to the direct limit.

    Exact mathematical passage
    P_{\infty,a}
\mathrm{phys}Use in source · 5 passages

Search aliases: phys mathrm

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  • Use in source · Read passage · 01_finite_core.tex, line 1003

    At resolution ℓ, define Q_ℓ = ( A_ℓ, H_ℓ, D_ℓ, {P_ℓ,α}, E_ℓ, C_ℓ, Π_ℓ^phys, T_ℓ ). In order, the entries specify the observable algebra, Hilbert space, geometric or Dirac-type operator, packet projectors, embedding into the fine space, reconstruction onto the coarse space, physical constraint projector, and transfer operator. The maps have types E_ℓ: H_ℓ→ H_ℓ+1 and C_ℓ: H_ℓ+1→ H_ℓ. The left inverse relation C_ℓ E_ℓ=I alone does not imply C_ℓ=E_ℓ^* or make the embedding isometric.

    Exact mathematical passage
    
    \boxed{
    \mathfrak Q_\ell
    =
    \left(
    \cA_\ell,
    \cH_\ell,
    D_\ell,
    \{P_{\ell,\alpha}\},
    E_\ell,
    C_\ell,
    \Pi_\ell^{\mathrm{phys}},
    T_\ell
    \right).
    }
    
\physUse in source · 10 passages

Search aliases: phys mathrm

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  • Use in source · Read passage · 02_strengthened.tex, line 45

    Constraint closure needs a different obstruction. If C_a are self adjoint constraints and P_phys projects onto their common kernel, then P_phys[C_a,C_b]P_phys=0 holds automatically. This compression cannot test closure. The correct finite obstruction is the class of [C_a,C_b] in the quotient of End( H) by the span of the constraints. Vanishing means that the constraint span is closed under commutators.

    Exact mathematical passage
    P_{\phys}
\pmodUse in source · 1 passage

Search aliases: pmod

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  • Use in source · Read passage · 01_finite_core.tex, line 247

    [Tensor/polyphase refinement] For each residue r∈ Z/N Z, define P_r^coarse = ∑_j_1+⋯+j_m≡ rpmod N P^(1)_j_1⊗⋯⊗ P^(m)_j_m. Then the P_r^coarse are complete orthogonal projectors, and every coarse packet is the exact sum of its fine descendants.

    Exact mathematical passage
    
    \boxed{
    P_r^{\mathrm{coarse}}
    =
    \sum_{j_1+\cdots+j_m\equiv r\pmod N}
    P^{(1)}_{j_1}\otimes\cdots\otimes P^{(m)}_{j_m}.
    }
    
\PrUse in source · 1 passage

Search aliases: Pr

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  • Use in source · monograph_atlas.tex, line 198

    in(ε t)X, normQe^- i tHP=|sin(ε t)|, norm[H,P]=|ε|. The general commutator estimate becomes the elementary bound |sin u|≤ |u|. Unitarity also bounds the amplitude by one. vfigleakage headFrom a norm to a probability For this initial state, the escape probability is sin^2(ε t), not |sin(ε t)|. Consequently Pr(hidden packet at t)≤min{1,ε^2t^2}. At ε t=π/6, the amplitude is 1/2 and the probability is 1/4. Near zero, amplitudes are first order while escape probabilities are second order. Mixing thos…

    Exact mathematical passage
    
    \Pr(\text{hidden packet at }t)\le\min\{1,\varepsilon^2t^2\}.
    
Q^2Use in source · 1 passage

Search aliases: Q^2

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  • Use in source · Read passage · 03_supplement_04.tex, line 107

    Constructing the recovery on the whole ambient space. Define the syndrome projectors and their complement by S_a=V_aV_a^*, S=∑_aS_a, Q=1-S. The source proves self-adjointness, S_aS_b=δ_abS_a, S^2=S, and Q^2=Q=Q^*. It also proves QV_a=0 and V_a^*Q=0.

    Exact mathematical passage
    Q^2=Q=Q^*
Q^\perpUse in source · 2 passages

Search aliases: Q^⊥ perp

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  • Use in source · Read passage · 02_strengthened.tex, line 1385

    The map R_0 is completely positive. It is trace preserving on operators supported in Q H because Tr(V_j^*Q_jXQ_jV_j) = Tr(Q_jXQ_j). Fix a code state ρ_0 and write Q^⊥=I-Q. Then R(X) = R_0(QXQ) + Tr(Q^⊥ X)ρ_0 is completely positive and trace preserving. It extends R_0 on operators supported in Q H.

    Exact mathematical passage
    Q^\perp=I-Q
q_1Use in source · 3 passages

Search aliases: q_1

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  • Use in source · Read passage · 02_strengthened.tex, line 369

    [Tensor selection rule] If A_a has local charge q_a, then A_1⊗⋯⊗ A_m has total charge q_1+⋯+q_m.

    Exact mathematical passage
    q_1+\cdots+q_m
Q_aUse in source · 12 passages

Search aliases: Q_a

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  • Use in source · monograph_atlas.tex, line 349

    vpage19Find the error without reading the logical stateFOUR EXACT SYNDROME PACKETSTraditional edition: Theorem II.8.2, Theorem II.8.4, Example II.8.8. Encode a qubit by ket0_L=ket000 and ket1_L=ket111. Let P project onto this code and take errors E_a∈{I,X_1,X_2,X_3}. Their images are four orthogonal rank-two packets Q_a=E_aPE_a^* that sum to the full identity. vfigsyndromes Use the logical state ψ=(3ket0_L+4ket1_L)/5 and channel probabilities w=(1,2,3,4)/10. The noisy state is ∑_aw_aE_aψψ^*E_a^*…

    Exact mathematical passage
    Q_a=E_aPE_a^*
q_aUse in source · 1 passage

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Q_a^*Use in source · 1 passage

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  • Use in source · Read passage · 03_supplement_02.tex, line 74

    Expanding the finite product of sums gives T(A) T(B)= T(i↦ A_iB_i). Consequently, if two fine addresses differ in any coordinate, the corresponding product contains a zero factor. If the addresses agree, the product is the same fine projector. The adjoint passes through the finite coordinate product, so Q_a^*=Q_a. Summing over all address functions and using the same expansion yields ∑_a Q_a= T(i↦∑_jP^(i)_j)=I. A separate algebraic regrouping theorem applies to any finite orthogonal family and a…

    Exact mathematical passage
    Q_a^*=Q_a
Q_cUse in source · 1 passage

Search aliases: Q_c

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  • Use in source · Read passage · 02_strengthened.tex, line 1042

    Let Φ:End( H_X)→End( H_Y) be linear. Choose packet systems (P_a) on H_X and (Q_c) on H_Y. Define Φ_cd,ab = Q_cdΦ P_ab.

    Exact mathematical passage
    (Q_c)
q_FUse in source · 2 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 1295

    Exact correction of an error span means that one completely positive trace preserving recovery R satisfies R(Fρ F^*)=q_Fρ for every F in that span and every code-supported matrix ρ, with a nonnegative scalar q_F depending on F but not on the logical input. For every normalized channel with Kraus operators in the same span, the same recovery restores the code input with total scalar one. Individual unnormalized errors are not required to have unit recovery weight.

    Exact mathematical passage
    \Rcal(F\rho F^*)=q_F\rho
Q_jUse in source · 7 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 1331

    the Knill Laflamme identities. Then the coefficient matrix c is positive semidefinite. Choose a unitary matrix W such that WcW^*=diag(λ_1,…,λ_r), λ_j≥0, and define F_j=∑_aoverlineW_jaE_a. For every j with λ_j>0, the operator V_j=λ_j^-1/2F_jP is an isometry from the code into H. Its range projector Q_j=V_jV_j^* is a syndrome packet, and the nonzero Q_j are pairwise orthogonal.

    Exact mathematical passage
    
    Q_j=V_jV_j^*
    
q_mUse in source · 3 passages

Search aliases: q_m

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  • Use in source · Read passage · 02_strengthened.tex, line 369

    [Tensor selection rule] If A_a has local charge q_a, then A_1⊗⋯⊗ A_m has total charge q_1+⋯+q_m.

    Exact mathematical passage
    q_1+\cdots+q_m
q_nUse in source · 4 passages

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  • Use in source · monograph_atlas.tex, line 788

    vpage40Choose the topology that preserves the quantityREFLECTION GRAMS, TRACES, AND FINAL SCOPETraditional edition: Theorem II.13.6, Theorem II.13.8, Section II.14. Let q_n=1/2+2^-(n+2) and define the scalar reflected kernel C_n(j,k)=1+q_n^j+k on nonnegative integers. Each finite Gram matrix is a sum of two positive rank-one matrices, and pointwise convergence gives C(j,k)=1+(1/2)^j+k. For times (0,1,2) and coefficients (1,-2,1), ∑_j,kv_jC_n(j,k)v_k=(1-q_n)^4≥0. This exact check illustrates how …

    Exact mathematical passage
    q_n=1/2+2^{-(n+2)}
q_n^{j+k}Use in source · 1 passage

Search aliases: q_n^j+k

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  • Use in source · monograph_atlas.tex, line 788

    vpage40Choose the topology that preserves the quantityREFLECTION GRAMS, TRACES, AND FINAL SCOPETraditional edition: Theorem II.13.6, Theorem II.13.8, Section II.14. Let q_n=1/2+2^-(n+2) and define the scalar reflected kernel C_n(j,k)=1+q_n^j+k on nonnegative integers. Each finite Gram matrix is a sum of two positive rank-one matrices, and pointwise convergence gives C(j,k)=1+(1/2)^j+k. For times (0,1,2) and coefficients (1,-2,1), ∑_j,kv_jC_n(j,k)v_k=(1-q_n)^4≥0. This exact check illustrates how …

    Exact mathematical passage
    C_n(j,k)=1+q_n^{j+k}
Q_rUse in source · 3 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 1740

    [Finite oscillatory memory expansion] If D=∑_rE_rQ_r is the spectral decomposition of the hidden Hamiltonian, then K(t)=∑_r e^- i tE_rBQ_rB^*. Every coefficient BQ_rB^* is positive semidefinite.

    Exact mathematical passage
    
    D=\sum_{r}E_rQ_r
    
q_rUse in source · 3 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 1236

    [Charge preservation by a Lindblad generator] Let S be unitary and N≥1 an integer with S^N=I. Assume SHS^*=H and, for every jump operator, there is a charge q_r such that SL_rS^*=ω^q_rL_r. Then the Lindblad generator G preserves every coherence order: G L_p= L_p G. The quantum dynamical semigroup e^t G has the same property.

    Exact mathematical passage
    q_r
\mathfrak Q_\ellUse in source · 1 passage

Search aliases: Q_ℓ mathfrak ell

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  • Use in source · Read passage · 01_finite_core.tex, line 1003

    At resolution ℓ, define Q_ℓ = ( A_ℓ, H_ℓ, D_ℓ, {P_ℓ,α}, E_ℓ, C_ℓ, Π_ℓ^phys, T_ℓ ). In order, the entries specify the observable algebra, Hilbert space, geometric or Dirac-type operator, packet projectors, embedding into the fine space, reconstruction onto the coarse space, physical constraint projector, and transfer operator. The maps have types E_ℓ: H_ℓ→ H_ℓ+1 and C_ℓ: H_ℓ+1→ H_ℓ. The left inverse relation C_ℓ E_ℓ=I alone does not imply C_ℓ=E_ℓ^* or make the embedding isometric.

    Exact mathematical passage
    
    \boxed{
    \mathfrak Q_\ell
    =
    \left(
    \cA_\ell,
    \cH_\ell,
    D_\ell,
    \{P_{\ell,\alpha}\},
    E_\ell,
    C_\ell,
    \Pi_\ell^{\mathrm{phys}},
    T_\ell
    \right).
    }
    
\QcalUse in source · 6 passages

Search aliases: Qcal Q mathcal

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  • Use in source · Read passage · 02_strengthened.tex, line 759

    Let (P_a) and (Q_a) be two complete packet systems with the same index set. Define S( Q, P)=∑_aQ_aP_a.

    Exact mathematical passage
    
    S(\Qcal,\Pcal)=\sum_aQ_aP_a.
    
\Qcal_{cd}Use in source · 1 passage

Search aliases: Qcal_cd Q_cd Qcal mathcal

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  • Use in source · Read passage · 02_strengthened.tex, line 1043

    Let Φ:End( H_X)→End( H_Y) be linear. Choose packet systems (P_a) on H_X and (Q_c) on H_Y. Define Φ_cd,ab = Q_cdΦ P_ab.

    Exact mathematical passage
    
    \Phi_{cd,ab}
    =
    \Qcal_{cd}\Phi\Pcal_{ab}.
    
\QQUse in source · 2 passages

Search aliases: QQ

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  • Use in source · monograph_atlas.tex, line 692

    egative. At t=π/2, it equals -16/25-9 i/25. xfigmemory_positive headPositive definite means a matrix test at arbitrary times For retained scalars v_j and real times t_j, the structural identity is ∑_j,koverline v_jK(t_j-t_k)v_k = ∑_k e^ i t_kDB^*v_k ^2≥0. The exact worked check specializes to t=(0,π/2,π) and v=(1,2,-1). Its phases lie in QQ( i), so both sides are computed without evaluating trigonometric functions. This Gram test illustrates the factorization. The written identity proves positiv…

    Exact mathematical passage
    \QQ(\ii)
\RUse in source · 5 passages

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  • Use in source · Read passage · 03_supplement_01.tex, line 150

    Checked stronger statement. For every k,h∈ R with h≠0, 0≤ k^2-λ_k,h≤frack^4h^212. The code proves this without the low-mode restriction. The bound may be loose away from the low-mode regime, but it remains valid.

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    k,h\in\R
\mathbb RUse in source · 1 passage

Search aliases: R mathbb

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  • Use in source · Read passage · 04_alternative_derivations.tex, line 5

    ses and notation agree with the corrected finite core. The earlier abbreviated argument for error correction is replaced by the complete normalized and scaled recovery proofs above, and its substantive conclusions are included there. Duhamel proof of leakage from a fixed packet. Let H=H^* on a finite-dimensional complex Hilbert space, P=P^*=P^2, Q=I-P, and t∈ R. [Alternative proof of the commutator leakage bound] Because QP=0, Qe^-itHP=Q[e^-itH,P]P. The Duhamel identity gives [e^-itH,P]=-i∫_0^t …

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    t\in\mathbb R
R'Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 2145

    By [source reference], Z_d(t) =(4π t)^-d/2(1+R(t)), where R(t)=∑_n≠0 e^-absn^2/(4t) =O( e^-1/(4t)). Differentiation gives tR'(t)=O(t^-1 e^-1/(4t)). Substituting this estimate into the logarithmic derivative gives the stated small time expansion.

    Exact mathematical passage
    
    tR'(t)=O\left(t^{-1}\e^{-1/(4t)}\right).
    
R^*Use in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 556

    vpage30Rotate whole packets by a polar factorAN EXACT LOCAL CHART AND ITS FAILURETraditional edition: Theorem II.6.5, Theorem II.6.6. On HH= C^2, put P_0=diag(1,0), P_1=I-P_0, and R=mat3/5 · -4/5 4/5 · 3/5, Q_a=RP_aR^*, S=∑_a=0^1Q_aP_a=frac35R. The exact Gram matrices give (S-I)^*(S-I)=frac1625I, S^*S=frac925I, normS-I=frac45<1. Consequently the unitary polar factor is S(S^*S)^-1/2=R, and Q_aR=RP_a for both complete packets. xfigpolar headThe norm condition selects a chart If the target rank-one…

    Exact mathematical passage
    
    R=\mat{3/5&-4/5\\4/5&3/5},\qquad Q_a=RP_aR^*,
    \qquad S=\sum_{a=0}^1Q_aP_a=\frac35R.
    
R^\nablaUse in source · 2 passages

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  • Use in source · Read passage · 03_supplement_06.tex, line 125

    Cancellation of the second derivatives. The product rule and the identity for the ambient Lie bracket reduce curvature to R^∇(X,Y)s=P d P[X] d s[Y]-P d P[Y] d s[X]. Substitute the identity obtained by differentiating the range condition for the section. The terms containing P d P[v]P vanish, leaving R^∇(X,Y)s= P( d P[X] d P[Y]- d P[Y] d P[X])P s. Lean also proves that this depends only on X(x), Y(x) and s(x), not on their extensions. The operator-valued form is alternating, additive and homogene…

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    R^\nabla(X,Y)s=P\dd P[X]\dd s[Y]-P\dd P[Y]\dd s[X].
    
R_1Use in source · 2 passages

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  • Use in source · monograph_atlas.tex, line 570

    Short steps can be composed before reaching a distant endpoint. For example, the rational step R_1=mat4/5 · -3/5 3/5 · 4/5 obeys R_1^2=mat7/25 · -24/25

    Exact mathematical passage
    R_1=\mat{4/5&-3/5\\3/5&4/5}
R_1^*Use in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 613

    The syndrome support is smaller than the ambient space. Define a total recovery with Kraus operators R_1=P, R_2=ket0bra2, R_1^*R_1+R_2^*R_2=I_3. It acts as the identity on operators supported on the code and sends the unused complement population into a chosen code state. The declared error map preserves the trace of code states, so recovery returns every code matrix unit, including both off-diagonal units, exactly. It need not preserve states on the unused complement. headExceptional cases and …

    Exact mathematical passage
    
    R_1=P,\qquad R_2=\ket0\bra2,
    \qquad R_1^*R_1+R_2^*R_2=I_3.
    
R_1^2Use in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 571

    3/5 · 4/5 obeys R_1^2=mat7/25 · -24/25 24/25 · 7/25. The multiplication is exact and each step has a valid local overlap. The convergence theorem has a separate analytic contract: a twice continuously differentiable complete projector path on a compact time interval, sufficiently fine partitions, and a constant depending on the path in an O(|π|) estimate in operator norm. headEvidence boundary The retained run checks the Gram identities, polar factor, intertwining, and product of two rational st…

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    R_1^2=\mat{7/25&-24/25\\24/25&7/25}.
    
R_2Use in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 613

    The syndrome support is smaller than the ambient space. Define a total recovery with Kraus operators R_1=P, R_2=ket0bra2, R_1^*R_1+R_2^*R_2=I_3. It acts as the identity on operators supported on the code and sends the unused complement population into a chosen code state. The declared error map preserves the trace of code states, so recovery returns every code matrix unit, including both off-diagonal units, exactly. It need not preserve states on the unused complement. headExceptional cases and …

    Exact mathematical passage
    
    R_1=P,\qquad R_2=\ket0\bra2,
    \qquad R_1^*R_1+R_2^*R_2=I_3.
    
R_2^*Use in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 613

    The syndrome support is smaller than the ambient space. Define a total recovery with Kraus operators R_1=P, R_2=ket0bra2, R_1^*R_1+R_2^*R_2=I_3. It acts as the identity on operators supported on the code and sends the unused complement population into a chosen code state. The declared error map preserves the trace of code states, so recovery returns every code matrix unit, including both off-diagonal units, exactly. It need not preserve states on the unused complement. headExceptional cases and …

    Exact mathematical passage
    
    R_1=P,\qquad R_2=\ket0\bra2,
    \qquad R_1^*R_1+R_2^*R_2=I_3.
    
R_aUse in source · 6 passages

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  • Use in source · monograph_atlas.tex, line 353

    rthogonal rank-two packets Q_a=E_aPE_a^* that sum to the full identity. vfigsyndromes Use the logical state ψ=(3ket0_L+4ket1_L)/5 and channel probabilities w=(1,2,3,4)/10. The noisy state is ∑_aw_aE_aψψ^*E_a^*. A syndrome measurement returns label a with probability w_a, independent of the logical amplitudes. headThe recovery is an actual channel The operators R_a=E_a^*Q_a satisfy ∑_aR_a^*R_a=I. Applying the recovery R(X)=∑_aR_aXR_a^* to the noisy state gives exactly ψψ^*. The off-diagonal logic…

    Exact mathematical passage
    R_a=E_a^*Q_a
R_a^*Use in source · 3 passages

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  • Use in source · monograph_atlas.tex, line 353

    ets Q_a=E_aPE_a^* that sum to the full identity. vfigsyndromes Use the logical state ψ=(3ket0_L+4ket1_L)/5 and channel probabilities w=(1,2,3,4)/10. The noisy state is ∑_aw_aE_aψψ^*E_a^*. A syndrome measurement returns label a with probability w_a, independent of the logical amplitudes. headThe recovery is an actual channel The operators R_a=E_a^*Q_a satisfy ∑_aR_a^*R_a=I. Applying the recovery R(X)=∑_aR_aXR_a^* to the noisy state gives exactly ψψ^*. The off-diagonal logical coherence 12/25 is r…

    Exact mathematical passage
    \sum_aR_a^*R_a=I
R_{\mathrm{extra}}Use in source · 2 passages

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  • Use in source · Read passage · 03_supplement_04.tex, line 109

    The recovery is not left undefined outside the syndrome subspaces. Its explicit Kraus operators are R_a=V_a^* together with R_extra=Q, giving R(ρ)=∑_aV_a^*ρ V_a+Qρ Q. They satisfy exact completeness: ∑_aR_a^*R_a+R_extra^*R_extra =∑_aV_aV_a^*+Q=S+Q=I. For finite complex matrices, trace preservation and complete positivity at every finite auxiliary dimension are proved for this actual map. The amplified map is identified with the Kraus family I_J⊗ R_a, including the complement term. Positivity is …

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    R_{\mathrm{extra}}=Q
R_{\mathrm{extra}}^*Use in source · 1 passage

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  • Use in source · Read passage · 03_supplement_04.tex, line 114

    The recovery is not left undefined outside the syndrome subspaces. Its explicit Kraus operators are R_a=V_a^* together with R_extra=Q, giving R(ρ)=∑_aV_a^*ρ V_a+Qρ Q. They satisfy exact completeness: ∑_aR_a^*R_a+R_extra^*R_extra =∑_aV_aV_a^*+Q=S+Q=I. For finite complex matrices, trace preservation and complete positivity at every finite auxiliary dimension are proved for this actual map. The amplified map is identified with the Kraus family I_J⊗ R_a, including the complement term. Positivity is …

    Exact mathematical passage
    
    \sum_aR_a^*R_a+R_{\mathrm{extra}}^*R_{\mathrm{extra}}
    =\sum_aV_aV_a^*+Q=S+Q=I.
    
R_nUse in source · 2 passages

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  • Use in source · monograph_atlas.tex, line 769

    vpage39Two routes to a bounded Hamiltonian limitEXACT EMBEDDINGS AND A SUMMABLE TAILTraditional edition: Theorem II.13.2, Theorem II.13.4, Corollary II.13.5. For the exact route, let HH_n= C^n with coordinate inclusions and H_n=diag(0,1,1/2,…,1/(n-1)), H_1=(0). The old energies are retained at every level, H_n+1R_n=R_nH_n, and normH_n≤1. On the Hilbert space of the direct limit ℓ^2( N_0), the diagonal sequence defines a bounded self-adjoint H_∞. Projectors onto even addresses also intertwine and…

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    H_{n+1}R_n=R_nH_n
R_PUse in source · 3 passages

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  • Use in source · Read passage · 03_supplement_04.tex, line 70

    Retaining the bracket of vector fields. Define the actual curvature action by R_P(X,Y)s=∇_X∇_Ys-∇_Y∇_Xs-∇_[X,Y]s. The source uses the Lie bracket defined through Fr echet derivatives. Symmetry of second derivatives is supplied by the C^2 hypothesis, not postulated separately. Expanding the connection gives R_P(X,Y)s=P(DP[X]Ds[Y]-DP[Y]Ds[X]). Substituting the section identity and removing the zero sandwich terms proves R_P(X,Y)s=P(DP[X]DP[Y]-DP[Y]DP[X])P s. Thus the coefficient is precisely P( d …

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    R_P(X,Y)s=\nabla_X\nabla_Ys-\nabla_Y\nabla_Xs-\nabla_{[X,Y]}s.
    
R_rUse in source · 5 passages

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  • Use in source · Read passage · 03_supplement_05.tex, line 10

    recise finite channel statement Let H= C^n be a finite coordinate space and let P=P^*=P^2. A matrix is code supported when Pρ P=ρ. For a finite family of square matrices E_a, put N_E(ρ)=∑_a E_aρ E_a^*. The input channel normalization is the actual matrix identity ∑_a E_a^*E_a=I. A finite Kraus recovery has the form R(σ)=∑_r R_rσ R_r^*, with ∑_rR_r^*R_r=I. This representation, together with the checked amplification results, provides complete positivity and trace preservation on the entire ambien…

    Exact mathematical passage
    \mathcal R(\sigma)=\sum_r R_r\sigma R_r^*
R_r^*Use in source · 3 passages

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  • Use in source · Read passage · 03_supplement_05.tex, line 10

    recise finite channel statement Let H= C^n be a finite coordinate space and let P=P^*=P^2. A matrix is code supported when Pρ P=ρ. For a finite family of square matrices E_a, put N_E(ρ)=∑_a E_aρ E_a^*. The input channel normalization is the actual matrix identity ∑_a E_a^*E_a=I. A finite Kraus recovery has the form R(σ)=∑_r R_rσ R_r^*, with ∑_rR_r^*R_r=I. This representation, together with the checked amplification results, provides complete positivity and trace preservation on the entire ambien…

    Exact mathematical passage
    \mathcal R(\sigma)=\sum_r R_r\sigma R_r^*
\RanUse in source · 6 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 598

    textitRange coordinates. Fix a∈ M and put T_a(x)=P(x)P(a)+(I-P(x))(I-P(a)). Then T_a(a)=I and P(x)T_a(x)=T_a(x)P(a). Invertibility is open, so on a neighborhood of a, T_a(x) restricts to an isomorphism from Ran P(a) to Ran P(x). This proves local constancy of rank. The local coordinates and their transitions are (x,v)⟼ (x,T_a(x)^-1v), u⟼ T_b(x)^-1T_a(x)u. Their smoothness follows from smoothness of P and inversion. The transition maps satisfy the cocycle identity by cancellation. These charts co…

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    \Ran P(a)
\Rcal_0Use in source · 4 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 1361

    [Exact recovery on the error span] Under the hypotheses of [source reference], define on the syndrome support Q=∑_λ_j>0Q_j the completely positive map R_0(X) = ∑_λ_j>0 V_j^*Q_jXQ_jV_j. It extends to a quantum channel R on End( H). If Φ(X)=∑_aE_aXE_a^* is trace preserving on code states, then RΦ(ρ)=ρ for every density matrix ρ=Pρ P.

    Exact mathematical passage
    
    \Rcal_0(X)
    =
    \sum_{\lambda_j>0}
    V_j^*Q_jXQ_jV_j.
    
\ReUse in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 156

    ity. Starting from ket0, there are two resolved paths to output ket1. Their signed products are bra1H_rm Hadket0bra0H_rm Hadket0=frac12, bra1H_rm Hadket1bra1H_rm Hadket0=-frac12. Their sum is zero. Squaring each separately gives a different answer. vfiginterference headWhere the missing term goes For path amplitudes a,b, the outcome probability is |a+b|^2=|a|^2+|b|^2+2Re(abar b). Here the last term is -1/2, canceling the first two terms. The path picture retains this information only if its edge…

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    |a+b|^2=|a|^2+|b|^2+2\Re(a\bar b)
\operatorname{Re}Use in source · 2 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 457

    [Path interference formula] Fix a source vector ψ∈ P_a_0 H and a target packet b. Let Γ_b be the set of packet paths from a_0 to b, and set η_γ=U_γψ. Choose any total order on this finite path set. Then normP_bUψ^2 = ∑_γ∈Γ_bnormη_γ^2 + 2Re ∑_substackγ,γ'∈Γ_b γ<γ' ipη_γη_γ'. Consequently, normP_bUψ ≤ ∑_γ∈Γ_bnormη_γ. If the path outputs are pairwise orthogonal, the target probability is the sum of the path probabilities.

    Exact mathematical passage
    
    \norm{P_bU\psi}^2
    =
    \sum_{\gamma\in\Gamma_b}\norm{\eta_\gamma}^2
    +
    2\operatorname{Re}
    \sum_{\substack{\gamma,\gamma'\in\Gamma_b\\ \gamma<\gamma'}}
    \ip{\eta_\gamma}{\eta_{\gamma'}}.
    
\operatorname{Row}Use in source · 2 passages

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  • Use in source · Read passage · 03_supplement_03.tex, line 8

    A matrix X belongs to O(C) exactly when each of its rows belongs to Row(C). One direction follows by expanding AC. For the converse, choose the coefficients producing each row separately and place them in the corresponding row of A. An explicit linear equivalence therefore gives O(C)≃ Row(C)^d, dim_ C O(C)=d rank C. If d>0, equality with the full d× m coefficient space is equivalent to rank C=m. Consequently a cyclic seed requires m≤ d. The assumption that there is at least one row is essential …

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    \operatorname{Row}(C)
S^{-r}Use in source · 2 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 221

    Using S^r+s=S^r+sbmod N and the finite character orthogonality relation, frac1N∑_r=0^N-1ω^(k-j)r=δ_jk, we obtain P_jP_k=δ_jkP_j. Summing over j cancels every term indexed by r≠0 and retains the r=0 term, which proves completeness. Unitarity and the change of residue r↦-r give P_j^*=frac1N∑_r=0^N-1ω^jrS^-r=P_j. Finally, multiplication by S shifts the summation index and contributes the factor ω^j.

    Exact mathematical passage
    
    P_j^*=\frac1N\sum_{r=0}^{N-1}\omega^{jr}S^{-r}=P_j.
    
S^2Use in source · 4 passages

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  • Use in source · monograph_atlas.tex, line 494

    age27One calculation of transfer to the opposite siteSEEDS, CHARACTERS, INTERFERENCE, AND DEPHASINGTraditional edition: Corollary II.3.3, Theorem II.4.4, Theorem II.7.4. Return to the shift on four sites S and Laplacian L=2I-S-S^*. The same character projectors have energies (0,2,4,2). At time t=π/2, their evolution phases are (1,-1,1,-1), exactly the character eigenvalues of S^2. Hence e^- iπ L/2=S^2, ket0⟼ket2. vfigperfect_transfer At halfway time π/4, the actual amplitude vector is (- i,1, i,…

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    S^2
S^NUse in source · 6 passages

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S^rUse in source · 4 passages

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  • Use in source · monograph_atlas.tex, line 93

    vpage6Four phases resolve a cyclic shiftCHARACTER PROJECTORS YOU CAN MULTIPLYTraditional edition: Corollary II.3.3. On four sites, let Sket k=ketk+1bmod4 and let ω= i. The character projectors are the exact matrices P_j=frac14∑_r=0^3 i^-jrS^r, v_j(k)=frac12 i^-jk, P_j=v_jv_j^*. All entries belong to the Gaussian rationals. Thus no approximation to a root of unity is needed in this model. vfigcyclic_four headReading the columns Each column v_j is a normalized wave around the four sites. Advancing…

    Exact mathematical passage
    
    P_j=\frac14\sum_{r=0}^3\ii^{-jr}S^r,
    \qquad v_j(k)=\frac12\ii^{-jk},\qquad P_j=v_jv_j^*.
    
S^{r+s}Use in source · 1 passage

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  • Use in source · Read passage · 01_finite_core.tex, line 216

    Using S^r+s=S^r+sbmod N and the finite character orthogonality relation, frac1N∑_r=0^N-1ω^(k-j)r=δ_jk, we obtain P_jP_k=δ_jkP_j. Summing over j cancels every term indexed by r≠0 and retains the r=0 term, which proves completeness. Unitarity and the change of residue r↦-r give P_j^*=frac1N∑_r=0^N-1ω^jrS^-r=P_j. Finally, multiplication by S shifts the summation index and contributes the factor ω^j.

    Exact mathematical passage
    S^{r+s}=S^{r+s\bmod N}
S^{r+s\bmod N}Use in source · 1 passage

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  • Use in source · Read passage · 01_finite_core.tex, line 216

    Using S^r+s=S^r+sbmod N and the finite character orthogonality relation, frac1N∑_r=0^N-1ω^(k-j)r=δ_jk, we obtain P_jP_k=δ_jkP_j. Summing over j cancels every term indexed by r≠0 and retains the r=0 term, which proves completeness. Unitarity and the change of residue r↦-r give P_j^*=frac1N∑_r=0^N-1ω^jrS^-r=P_j. Finally, multiplication by S shifts the summation index and contributes the factor ω^j.

    Exact mathematical passage
    S^{r+s}=S^{r+s\bmod N}
S^{\operatorname{val}(r)}Use in source · 1 passage

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  • Use in source · Read passage · 03_supplement_03.tex, line 98

    003 Let N>0 and let S be a unitary complex matrix with S^N=I. The implementation uses the standard additive character of Z/N Z and proves its expression through a root of unity: ω=exp(2π i/N), χ(r)=ω^val(r). Here val(r) is the canonical representative in {0,…,N-1}. The representation is constructed as ρ(r)=S^val(r). Reduction of exponents modulo N is proved from S^N=I, giving ρ(r+s)=ρ(r)ρ(s) and ρ(0)=I. The final matrix theorem derives the representation law and character orthogonality from the …

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    \rho(r)=S^{\operatorname{val}(r)}.
    
S_3Use in source · 4 passages

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  • Use in source · monograph_atlas.tex, line 533

    imitation of testing only the common kernel on pagerefV26. takeawayExact finite structure is valuable because its boundary is explicit. The appendix adds understanding and reproducibility, not unproved continuum claims or a new theorem count. vpage29Nonabelian packets carry multiplicityA SIX-DIMENSIONAL REGULAR REPRESENTATIONTraditional edition: Theorem II.3.1, Theorem II.3.2. Let HH= C[S_3] have the six orthonormal basis vectors ket g, with left action U(h)ket g=kethg. The irreducible character…

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    \HH=\CC[S_3]
S_aUse in source · 2 passages

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  • Use in source · Read passage · 03_supplement_04.tex, line 104

    Constructing the recovery on the whole ambient space. Define the syndrome projectors and their complement by S_a=V_aV_a^*, S=∑_aS_a, Q=1-S. The source proves self-adjointness, S_aS_b=δ_abS_a, S^2=S, and Q^2=Q=Q^*. It also proves QV_a=0 and V_a^*Q=0.

    Exact mathematical passage
    
    S_a=V_aV_a^*,\qquad S=\sum_aS_a,\qquad Q=1-S.
    
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  • Use in source · Read passage · 03_supplement_04.tex, line 107

    Constructing the recovery on the whole ambient space. Define the syndrome projectors and their complement by S_a=V_aV_a^*, S=∑_aS_a, Q=1-S. The source proves self-adjointness, S_aS_b=δ_abS_a, S^2=S, and Q^2=Q=Q^*. It also proves QV_a=0 and V_a^*Q=0.

    Exact mathematical passage
    S_aS_b=\delta_{ab}S_a
S_zUse in source · 5 passages

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  • Use in source · Read passage · 03_supplement_01.tex, line 106

    -C · zI_Q-D. Set D_z=zI_Q-D, S_z=zI_P-A-BD_z^-1C. The effective Hamiltonian is H_eff(z)=A+BD_z^-1C, so S_z=zI_P-H_eff(z).

    Exact mathematical passage
    
    D_z=zI_Q-D,\qquad S_z=zI_P-A-BD_z^{-1}C.
    
S_z^{-1}Use in source · 1 passage

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  • Use in source · Read passage · 03_supplement_01.tex, line 114

    Correct statement: source Theorem 9.1. Assume both D_z and zI-H are invertible. Then S_z is invertible and ((zI-H)^-1)_PP=S_z^-1. The left side is the submatrix of the full inverse on the retained coordinates. This matches the paper's compressed operator when written in an orthonormal basis of the retained subspace. The proof is valid for arbitrary complex blocks of compatible sizes and does not require Hermiticity.

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    \boxed{\bigl((zI-H)^{-1}\bigr)_{PP}=S_z^{-1}.}
    
\sinUse in source · 45 passages

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  • Use in source · monograph_atlas.tex, line 188

    vpage11Quantify the amplitude that escapesCOMMUTATORS AND PROBABILITY BOUNDSTraditional edition: Theorem II.5.3, Corollary II.5.4. For a two-level system, choose H=ε X, P=ket0bra0, and Q=I-P. Direct exponentiation gives e^- i tH=cos(ε t)I- isin(ε t)X, normQe^- i tHP=|sin(ε t)|, norm[H,P]=|ε|. The general commutator estimate becomes the elementary bound |sin u|≤ |u|. Unitarity also bounds the amplitude by one. vfigleakage headFrom a norm to a probability For this initial state, the escape probabi…

    Exact mathematical passage
    
    e^{-\ii tH}=\cos(\varepsilon t)I-\ii\sin(\varepsilon t)X,
    \quad
    \norm{Qe^{-\ii tH}P}=|\sin(\varepsilon t)|,
    \quad\norm{[H,P]}=|\varepsilon|.
    
\sin^2Use in source · 16 passages

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  • Use in source · monograph_atlas.tex, line 197

    irect exponentiation gives e^- i tH=cos(ε t)I- isin(ε t)X, normQe^- i tHP=|sin(ε t)|, norm[H,P]=|ε|. The general commutator estimate becomes the elementary bound |sin u|≤ |u|. Unitarity also bounds the amplitude by one. vfigleakage headFrom a norm to a probability For this initial state, the escape probability is sin^2(ε t), not |sin(ε t)|. Consequently Pr(hidden packet at t)≤min{1,ε^2t^2}. At ε t=π/6, the amplitude is 1/2 and the probability is 1/4. Near zero, amplitudes are first order while e…

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    \sin^2(\varepsilon t)
\SpanUse in source · 2 passages

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  • Use in source · monograph_atlas.tex, line 61

    ment changes the local spanSCHMIDT RANK AS ACCESSIBLE MULTIPLICITYTraditional edition: Theorem II.2.2, Corollary II.2.4. Write a bipartite vector as a coefficient matrix C, with the first subsystem indexing rows. Acting only on that subsystem transforms C to AC. Every resulting row remains in the row space of C, and every independent choice of such rows can be obtained in this way. dimSpan{(A⊗ I)ψ:A∈ M_d( C)} =d rank C. vfiglocal_orbits The product vector ket00 has matrix C=diag(1,0). Its local …

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    \dim\Span\{(A\otimes I)\psi:A\in M_d(\CC)\}
    =d\,\rank C.
    
\operatorname{span}_{\CC}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 2175

    Let C_1,…,C_m be self adjoint constraint operators on a finite dimensional Hilbert space. The distinction between constraint action and constraint closure is standard in constrained Hamiltonian theory [source reference]. Write c=span_ C{C_1,…,C_m} ⊆End( H).

    Exact mathematical passage
    
    \mathfrak c=\operatorname{span}_{\CC}\{C_1,\ldots,C_m\}
    \subseteq\End(\Hcal).
    
\spanofUse in source · 1 passage

Search aliases: spanof span operatorname

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  • Use in source · Read passage · 03_supplement_03.tex, line 63

    The matrix-orbit dimension and the coefficient equivalence now yield dim_ Cspan{(A⊗ I_B)ψ:A∈ M_d_A( C)} =d_A r(ψ).

    Exact mathematical passage
    
    \boxed{\dim_\C\spanof\{(A\otimes I_B)\psi:A\in M_{d_A}(\C)\}
    =d_A r(\psi).}
    
\Spec_\RUse in source · 2 passages

Search aliases: Spec_R Spec_ R Spec R operatorname mathbb

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  • Use in source · Read passage · 03_supplement_03.tex, line 147

    tual matrix exponential with continuous functional calculus: T_e(t)=f_t(H), f_t(x)=e^-t(x-e). The formal proof uses composition, scalar multiplication, subtraction, and the established agreement between the exponential in functional calculus and the exponential defined by a power series. Spectral mapping is consequently available for the operator that was actually defined: Spec_ R T_e(t)={e^-t(x-e):x∈Spec_ R H}. Hermiticity also identifies the full complex spectrum with the image of these real e…

    Exact mathematical passage
    
    \Spec_\R T_e(t)=\{e^{-t(x-e)}:x\in\Spec_\R H\}.
    
\operatorname{srank}Use in source · 3 passages

Search aliases: srank operatorname

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  • Use in source · monograph_atlas.tex, line 83

    dimensional state space. vfigseed_rank headFrom the example to the finite formula For a block M_d( C)⊗ I_m, k seed matrices contribute at most kd independent multiplicity directions. Hence k≥lceil m/drceil. Partitioning a multiplicity basis into groups of size at most d attains this bound. For a direct sum of such blocks, the worst block determines the required count: srank_AA(HH)=max_ilceil m_i/d_irceil. This is an invariant of the declared representation of the algebra, and depends on more tha…

    Exact mathematical passage
    
    \operatorname{srank}_{\AA}(\HH)=\max_i\lceil m_i/d_i\rceil.
    
\operatorname{srank}_{\AA}Use in source · 1 passage

Search aliases: srank_AA operatorname AA

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  • Use in source · monograph_atlas.tex, line 83

    dimensional state space. vfigseed_rank headFrom the example to the finite formula For a block M_d( C)⊗ I_m, k seed matrices contribute at most kd independent multiplicity directions. Hence k≥lceil m/drceil. Partitioning a multiplicity basis into groups of size at most d attains this bound. For a direct sum of such blocks, the worst block determines the required count: srank_AA(HH)=max_ilceil m_i/d_irceil. This is an invariant of the declared representation of the algebra, and depends on more tha…

    Exact mathematical passage
    
    \operatorname{srank}_{\AA}(\HH)=\max_i\lceil m_i/d_i\rceil.
    
\operatorname{srank}_{\Acal}Use in source · 1 passage

Search aliases: srank_Acal srank_ A operatorname Acal operatorname mathcal

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  • Use in source · Read passage · 02_strengthened.tex, line 135

    [Quantum seed rank] For the displayed multiplicity decomposition, srank_ A( H) = max_1≤ r≤ s lceilfracm_rd_rrceil.

    Exact mathematical passage
    
    \operatorname{srank}_{\Acal}(\Hcal)
    =
    \max_{1\le r\le s}
    \left\lceil\frac{m_r}{d_r}\right\rceil.
    
\operatorname{srank}_{\cA}Use in source · 1 passage

Search aliases: srank_cA srank_ A operatorname cA operatorname mathcal

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  • Use in source · Read passage · 01_finite_core.tex, line 117

    [Quantum seed-rank formula] For A=⊕_i(M_d_i( C)⊗ I_m_i) on H=⊕_i( C^d_i⊗ C^m_i), the minimum number of seeds required to generate H is srank_ A( H) = max_ilceilfracm_id_irceil.

    Exact mathematical passage
    
    \boxed{
    \operatorname{srank}_{\cA}(\cH)
    =
    \max_i\left\lceil\frac{m_i}{d_i}\right\rceil.
    }
    
\succUse in source · 1 passage

Search aliases: succ

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  • Use in source · Read passage · 01_finite_core.tex, line 1026

    A coherent refinement should satisfy C_ℓ E_ℓ=I and P_ℓ,α = C_ℓ ( ∑_βsuccαP_ℓ+1,β ) E_ℓ. For an operator D, define the refinement defect Δ_ℓ(D) =C_ℓ D_ℓ+1E_ℓ-D_ℓ. Exact resolution independence is Δ_ℓ(D)=0. When exact equality is too strong, the correct continuum problem is to prove convergence of the resolvents and uniform control of the effective self-energies.

    Exact mathematical passage
    
    \boxed{
    P_{\ell,\alpha}
    =
    C_\ell
    \left(
    \sum_{\beta\succ\alpha}P_{\ell+1,\beta}
    \right)
    E_\ell.
    }
    
\succeqUse in source · 4 passages

Search aliases: succeq

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  • Use in source · Read passage · 03_supplement_02.tex, line 203

    Matrix multiplication distributes across addition and scalar multiplication, which gives complex linearity. If ρsucceq0, each term K_aρ K_a^* is positive semidefinite, hence so is their finite sum.

    Exact mathematical passage
    \rho\succeq0
\supUse in source · 4 passages

Search aliases: sup

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  • Use in source · Read passage · 02_strengthened.tex, line 2372

    [Bounded Hamiltonian direct limit] Assume H_ℓ+1R_ℓ=R_ℓ H_ℓ and sup_ℓnormH_ℓ<∞. Then there is a unique bounded self adjoint operator H_∞ on H_∞ such that H_∞ι_ℓ=ι_ℓ H_ℓ for every ℓ. It satisfies e^- i tH_∞ι_ℓ = ι_ℓ e^- i tH_ℓ and e^-tH_∞ι_ℓ = ι_ℓ e^-tH_ℓ when the Hamiltonians are nonnegative.

    Exact mathematical passage
    
    \sup_\ell\norm{H_\ell}<\infty.
    
\sup_{0\leq t\leq T}Use in source · 1 passage

Search aliases: sup_0≤ t≤ T sup leq leq

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  • Use in source · Read passage · 02_strengthened.tex, line 2435

    Let (H_n) be bounded self adjoint operators on one Hilbert space and assume ∑_n=0^∞normH_n+1-H_n<∞. Then H_n converges in norm to a bounded self adjoint operator H. For every T>0, sup_abs t≤ T norm e^- i tH_n- e^- i tH ≤ TnormH_n-H. If every H_n≥0, then sup_0≤ t≤ T norm e^-tH_n- e^-tH ≤ TnormH_n-H.

    Exact mathematical passage
    
    \sup_{0\leq t\leq T}
    \norm{\e^{-tH_n}-\e^{-tH}}
    \leq
    T\norm{H_n-H}.
    
\sup_{\abs t\leq T}Use in source · 2 passages

Search aliases: sup_abs t≤ T sup abs leq

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  • Use in source · Read passage · 02_strengthened.tex, line 2428

    [Norm summable Hamiltonian tower] Let (H_n) be bounded self adjoint operators on one Hilbert space and assume ∑_n=0^∞normH_n+1-H_n<∞. Then H_n converges in norm to a bounded self adjoint operator H. For every T>0, sup_abs t≤ T norm e^- i tH_n- e^- i tH ≤ TnormH_n-H. If every H_n≥0, then sup_0≤ t≤ T norm e^-tH_n- e^-tH ≤ TnormH_n-H.

    Exact mathematical passage
    
    \sup_{\abs t\leq T}
    \norm{\e^{-\ii tH_n}-\e^{-\ii tH}}
    \leq
    T\norm{H_n-H}.
    
\sup_\ellUse in source · 1 passage

Search aliases: sup_ℓ sup ell

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  • Use in source · Read passage · 02_strengthened.tex, line 2372

    [Bounded Hamiltonian direct limit] Assume H_ℓ+1R_ℓ=R_ℓ H_ℓ and sup_ℓnormH_ℓ<∞. Then there is a unique bounded self adjoint operator H_∞ on H_∞ such that H_∞ι_ℓ=ι_ℓ H_ℓ for every ℓ. It satisfies e^- i tH_∞ι_ℓ = ι_ℓ e^- i tH_ℓ and e^-tH_∞ι_ℓ = ι_ℓ e^-tH_ℓ when the Hamiltonians are nonnegative.

    Exact mathematical passage
    
    \sup_\ell\norm{H_\ell}<\infty.
    
\tUse in source · 2 passages

Search aliases: t

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  • Use in source · defect.tex, line 4

    draw[->] (1,1.6)--(11,1.6);foreach x/t in 3/9/10,6/1,9/11/10 fill (x,1.6) circle (0.08);node[below] at (x,1.5) t; draw[<->] (3,2.5)--(6,2.5);draw[<->] (6,2.5)--(9,2.5); node[above] at (4.5,2.5) 1/10;node[above] at (7.5,2.5) 1/10; node[font=small] at (6,0.45) one pair: 1/10, full family {I,A}: 1/5;

    Exact mathematical passage
    \t
t^{-1}Use in source · 2 passages

Search aliases: t^-1

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  • Use in source · Read passage · 02_strengthened.tex, line 2125

    [Continuum torus small time dimension] Let d_rm torus(t) =-2frac dlog Z_d(t) dlog t. Then d_rm torus(t) = d+O(t^-1 e^-1/(4t)) as tdownarrow0.

    Exact mathematical passage
    
    d_{\rm torus}(t)
    =
     d+O\left(t^{-1}\e^{-1/(4t)}\right)
    
t^2Use in source · 2 passages

Search aliases: t^2

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  • Use in source · monograph_atlas.tex, line 198

    in(ε t)X, normQe^- i tHP=|sin(ε t)|, norm[H,P]=|ε|. The general commutator estimate becomes the elementary bound |sin u|≤ |u|. Unitarity also bounds the amplitude by one. vfigleakage headFrom a norm to a probability For this initial state, the escape probability is sin^2(ε t), not |sin(ε t)|. Consequently Pr(hidden packet at t)≤min{1,ε^2t^2}. At ε t=π/6, the amplitude is 1/2 and the probability is 1/4. Near zero, amplitudes are first order while escape probabilities are second order. Mixing thos…

    Exact mathematical passage
    
    \Pr(\text{hidden packet at }t)\le\min\{1,\varepsilon^2t^2\}.
    
T^{n_j}Use in source · 2 passages

Search aliases: T^n_j

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  • Use in source · monograph_atlas.tex, line 717

    tive lower bound on the gap. Ground multiplicity does not cause a problem: P_0 selects the entire eigenspace at the minimum energy. For a Hamiltonian whose minimum is E_0≠0, the normalized transfer is e^-t(H-E_0I) before taking the limit. headPositivity is retained at several Euclidean times For arbitrary vectors u_j and nonnegative integer times n_j, the reflected kernel obeys ∑_j,k⟨ u_j,T^n_j+n_ku_k⟩ = ∑_jT^n_ju_j ^2. This is a finite Gram factorization. The retained run checks the integer sem…

    Exact mathematical passage
    
    \sum_{j,k}\langle u_j,T^{n_j+n_k}u_k\rangle
    =\left\|\sum_jT^{n_j}u_j\right\|^2.
    
T^{n_j+n_k}Use in source · 5 passages

Search aliases: T^n_j+n_k

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  • Use in source · monograph_atlas.tex, line 717

    tive lower bound on the gap. Ground multiplicity does not cause a problem: P_0 selects the entire eigenspace at the minimum energy. For a Hamiltonian whose minimum is E_0≠0, the normalized transfer is e^-t(H-E_0I) before taking the limit. headPositivity is retained at several Euclidean times For arbitrary vectors u_j and nonnegative integer times n_j, the reflected kernel obeys ∑_j,k⟨ u_j,T^n_j+n_ku_k⟩ = ∑_jT^n_ju_j ^2. This is a finite Gram factorization. The retained run checks the integer sem…

    Exact mathematical passage
    
    \sum_{j,k}\langle u_j,T^{n_j+n_k}u_k\rangle
    =\left\|\sum_jT^{n_j}u_j\right\|^2.
    
T^{n_k}Use in source · 2 passages

Search aliases: T^n_k

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  • Use in source · Read passage · 02_strengthened.tex, line 1890

    Since T is positive and self adjoint, ipv_jT^n_j+n_kv_k = ipT^n_jv_jT^n_kv_k. The quadratic form is the squared norm of ∑_kc_kT^n_kv_k.

    Exact mathematical passage
    
    \ip{v_j}{T^{n_j+n_k}v_k}
    =
    \ip{T^{n_j}v_j}{T^{n_k}v_k}.
    
T_0Use in source · 1 passage

Search aliases: T_0

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  • Use in source · monograph_atlas.tex, line 261

    E_x={v:P(x)v=v}. To compare it with a nearby anchor fiber E_a, the completion proof constructs T_a(x)=P(x)P(a)+(I-P(x))(I-P(a)). It equals the identity at the anchor and intertwines the two projectors. Where it is invertible, its restriction provides local fiber coordinates. vfigrange_atlas headAn exact example of the domain restriction For the rotating line and anchor P(0), T_0(t)=cos t U(t), det T_0(t)=cos^2t. The chart fails at t=π/2, but P(π/2)=diag(0,1) is a perfectly regular rank-one proje…

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    T_0(t)=\cos t\,U(t),\qquad \det T_0(t)=\cos^2t.
    
t_0Use in source · 2 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 800

    [Convergence of short packet rotations] Let (P_a(t)) be twice continuously differentiable on [0,T]. For a partition 0=t_0<t_1<⋯<t_n=T, let W_π = U( P(t_n), P(t_n-1)) ⋯ U( P(t_1), P(t_0)). For sufficiently fine partitions the factors are defined, and normW_π-W(T) ≤ C_Tabsπ for a constant depending on the packet path but not on the partition. Here the size of the partition is measured by its mesh, which is the length of its largest subinterval.

    Exact mathematical passage
    
    0=t_0<t_1<\cdots<t_n=T,
    
t_1Use in source · 3 passages

Search aliases: t_1

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  • Use in source · Read passage · 02_strengthened.tex, line 800

    [Convergence of short packet rotations] Let (P_a(t)) be twice continuously differentiable on [0,T]. For a partition 0=t_0<t_1<⋯<t_n=T, let W_π = U( P(t_n), P(t_n-1)) ⋯ U( P(t_1), P(t_0)). For sufficiently fine partitions the factors are defined, and normW_π-W(T) ≤ C_Tabsπ for a constant depending on the packet path but not on the partition. Here the size of the partition is measured by its mesh, which is the length of its largest subinterval.

    Exact mathematical passage
    
    0=t_0<t_1<\cdots<t_n=T,
    
t_aUse in source · 3 passages

Search aliases: t_a

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  • Use in source · monograph_atlas.tex, line 430

    ens also to have nonnegative entries and column sums one. Conjugate by the unitary Z. The spectrum and positivity of the quadratic form are preserved, but both off-diagonal entries become -1/4. Thus positivity as an operator is not entrywise positivity and does not by itself give a Markov interpretation. headA useful finite positive kernel For this nonnegative H, vectors u_a and times t_a≥0 satisfy ∑_a,b⟨ u_a,e^-(t_a+t_b)Hu_b⟩ = ∑_a e^-t_aHu_a ^2≥0. The factorization makes positivity transparent…

    Exact mathematical passage
    t_a\ge0
T_{a+b}Use in source · 1 passage

Search aliases: T_a+b

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  • Use in source · Read passage · 03_supplement_02.tex, line 29

    Composition gives T_aT_b=T_a+b, and direct evaluation gives T_aket b=keta+b. Every binary address satisfies a+a=0, so each translation is an involution. In particular, the local operator changes precisely the addressed bit: X_jket a=keta with coordinate j replaced by a_j+1. The selected factor at j equals translation by the address supported at j with value a_j. Induction on a list proves that the product of translations is translation by their sum. Each of these addresses contributes one coordi…

    Exact mathematical passage
    T_aT_b=T_{a+b}
T_bUse in source · 2 passages

Search aliases: T_b

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  • Use in source · Read passage · 01_finite_core.tex, line 599

    textitRange coordinates. Fix a∈ M and put T_a(x)=P(x)P(a)+(I-P(x))(I-P(a)). Then T_a(a)=I and P(x)T_a(x)=T_a(x)P(a). Invertibility is open, so on a neighborhood of a, T_a(x) restricts to an isomorphism from Ran P(a) to Ran P(x). This proves local constancy of rank. The local coordinates and their transitions are (x,v)⟼ (x,T_a(x)^-1v), u⟼ T_b(x)^-1T_a(x)u. Their smoothness follows from smoothness of P and inversion. The transition maps satisfy the cocycle identity by cancellation. These charts co…

    Exact mathematical passage
    
    (x,v)\longmapsto (x,T_a(x)^{-1}v),\qquad
    u\longmapsto T_b(x)^{-1}T_a(x)u.
    
t_bUse in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 431

    nnegative entries and column sums one. Conjugate by the unitary Z. The spectrum and positivity of the quadratic form are preserved, but both off-diagonal entries become -1/4. Thus positivity as an operator is not entrywise positivity and does not by itself give a Markov interpretation. headA useful finite positive kernel For this nonnegative H, vectors u_a and times t_a≥0 satisfy ∑_a,b⟨ u_a,e^-(t_a+t_b)Hu_b⟩ = ∑_a e^-t_aHu_a ^2≥0. The factorization makes positivity transparent. It remains a fini…

    Exact mathematical passage
    
    \sum_{a,b}\langle u_a,e^{-(t_a+t_b)H}u_b\rangle
    =\left\|\sum_a e^{-t_aH}u_a\right\|^2\ge0.
    
T_eUse in source · 5 passages

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  • Use in source · Read passage · 03_supplement_03.tex, line 136

    The actual Euclidean transfer exponential. Let H be a Hermitian matrix on a nonzero complex state space of finite dimension. The source defines T_e(t)=exp(-t(H-eI)) using Lean's exponential defined by a power series. The proof then relates this defined operator to its spectral expansion.

    Exact mathematical passage
    
    T_e(t)=\exp\bigl(-t(H-eI)\bigr)
    
T_{E_0}Use in source · 1 passage

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  • Use in source · Read passage · 03_supplement_03.tex, line 161

    Positivity, semigroup composition, and the interval. Every eigenvalue of T_e(t) is strictly positive, for arbitrary real e,t, since the real exponential is positive. For e=E_0 and t≥0 it is also at most one. Therefore T_E_0(t)>0, Spec T_E_0(t)⊆(0,1]. The two scalar multiples of H-eI commute, so the exponential defined by the power series obeys T_e(t+s)=T_e(t)T_e(s), T_e(0)=I. The semigroup identity is proved for all real t,s. Nonnegative time is needed for the upper spectral bound, not for the c…

    Exact mathematical passage
    
    \boxed{T_{E_0}(t)>0,\qquad \Spec T_{E_0}(t)\subseteq(0,1].}
    
T_{e_j}Use in source · 1 passage

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  • Use in source · Read passage · 03_supplement_02.tex, line 17

    0 · x≠ a. The seed is ψ_0=ket0. Define a translation operator by (T_a v)(x)=v(x-a). At position j, the local Pauli X is X_j=T_e_j, where e_j has a single nonzero binary coordinate. The formal circuit uses the identity when a_j=0 and X_j when a_j=1.

    Exact mathematical passage
    X_j=T_{e_j}
t_jUse in source · 5 passages

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  • Use in source · monograph_atlas.tex, line 687

    4/5 · 0 · 2. Its memory kernel is K(t)=frac925e^- i t+frac1625e^-2 i t, K(0)=1. Each oscillatory coefficient is positive although K(t) need not be real or pointwise nonnegative. At t=π/2, it equals -16/25-9 i/25. xfigmemory_positive headPositive definite means a matrix test at arbitrary times For retained scalars v_j and real times t_j, the structural identity is ∑_j,koverline v_jK(t_j-t_k)v_k = ∑_k e^ i t_kDB^*v_k ^2≥0. The exact worked check specializes to t=(0,π/2,π) and v=(1,2,-1). Its phase…

    Exact mathematical passage
    t_j
t_{j+1}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 837

    es S( P(t+h), P(t)) = I+hK(t)+O(h^2) uniformly on [0,T]. Since K(t)^*=-K(t), S^*S=I+O(h^2), so the polar factor satisfies U( P(t+h), P(t)) = I+hK(t)+O(h^2). This gives a first order approximation to dot W=KW over a single time step. A telescoping product estimate over the partition gives a total error bounded by a constant times ∑_j(t_j+1-t_j)^2, which is at most Tabsπ.

    Exact mathematical passage
    \sum_j(t_{j+1}-t_j)^2
t_kUse in source · 4 passages

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  • Use in source · monograph_atlas.tex, line 688

    ts memory kernel is K(t)=frac925e^- i t+frac1625e^-2 i t, K(0)=1. Each oscillatory coefficient is positive although K(t) need not be real or pointwise nonnegative. At t=π/2, it equals -16/25-9 i/25. xfigmemory_positive headPositive definite means a matrix test at arbitrary times For retained scalars v_j and real times t_j, the structural identity is ∑_j,koverline v_jK(t_j-t_k)v_k = ∑_k e^ i t_kDB^*v_k ^2≥0. The exact worked check specializes to t=(0,π/2,π) and v=(1,2,-1). Its phases lie in QQ( i…

    Exact mathematical passage
    
    \sum_{j,k}\overline v_jK(t_j-t_k)v_k
    =\left\|\sum_k e^{\ii t_kD}B^*v_k\right\|^2\geq0.
    
t_mUse in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 1713

    [Positive definite quantum memory] The kernel K(t-s) is positive definite. For times t_1,…,t_m and retained vectors v_1,…,v_m, ∑_j,k=1^m ipv_jK(t_j-t_k)v_k ≥0.

    Exact mathematical passage
    t_1,\ldots,t_m
T_nUse in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 797

    For transfers on two states T_n=diag(1,q_n)=e^-H_n, with H_n=diag(0,-log q_n) at unit time, the error in trace norm is 2^-(n+2) and the heat traces converge to 3/2. The criterion for convergence of spectral dimension additionally assumes convergence of the first heat moments in trace norm and a nonzero limiting heat trace. Convergence of the heat trace alone does not determine that quotient. headThe retained evidence and the remaining open targets The extension includes retained exact checks ove…

    Exact mathematical passage
    T_n=\diag(1,q_n)=e^{-H_n}
t_NUse in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 740

    It does not assert a uniform interval width from that argument, a moving time t_N with no extra estimates, or a dimension plateau at every scale. At fixed finite N, d_N(t)→0 as tdownarrow0 and as t→∞. By contrast, first taking N→∞ at positive t and then taking tdownarrow0 yields the continuum dimension. headWhere the infinite tail is controlled At a fixed time, the proof bounds centered modes below by 16k^2 and above by 4π^2k^2. The summable Gaussian dominators control both the heat trace and it…

    Exact mathematical passage
    t_N
t_nUse in source · 2 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 800

    [Convergence of short packet rotations] Let (P_a(t)) be twice continuously differentiable on [0,T]. For a partition 0=t_0<t_1<⋯<t_n=T, let W_π = U( P(t_n), P(t_n-1)) ⋯ U( P(t_1), P(t_0)). For sufficiently fine partitions the factors are defined, and normW_π-W(T) ≤ C_Tabsπ for a constant depending on the packet path but not on the partition. Here the size of the partition is measured by its mesh, which is the length of its largest subinterval.

    Exact mathematical passage
    
    0=t_0<t_1<\cdots<t_n=T,
    
t_{n-1}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 804

    [Convergence of short packet rotations] Let (P_a(t)) be twice continuously differentiable on [0,T]. For a partition 0=t_0<t_1<⋯<t_n=T, let W_π = U( P(t_n), P(t_n-1)) ⋯ U( P(t_1), P(t_0)). For sufficiently fine partitions the factors are defined, and normW_π-W(T) ≤ C_Tabsπ for a constant depending on the packet path but not on the partition. Here the size of the partition is measured by its mesh, which is the length of its largest subinterval.

    Exact mathematical passage
    
    W_\pi
    =
    \Ucal\bigl(\Pcal(t_n),\Pcal(t_{n-1})\bigr)
    \cdots
    \Ucal\bigl(\Pcal(t_1),\Pcal(t_0)\bigr).
    
T_PUse in source · 3 passages

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  • Use in source · Read passage · 03_supplement_04.tex, line 10

    Deriving the estimate by differentiation. For a skew-adjoint generator G, define the actual conjugation path T_P(t)=exp(tG)Pexp(-tG). The formalization derives its derivative from the exponential power series and the product rule: T_P'(t)=exp(tG)(GP-PG)exp(-tG). Both exponential factors are proved unitary. Left and right multiplication by a unitary preserve the C-star norm. Therefore T_P'(t) = GP-PG , T_P(t)-T_P(s) ≤ |t-s| GP-PG . The second inequality follows from the mean value inequality in n…

    Exact mathematical passage
    
    T_P(t)=\exp(tG)P\exp(-tG).
    
T_P'Use in source · 2 passages

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  • Use in source · Read passage · 03_supplement_04.tex, line 14

    Deriving the estimate by differentiation. For a skew-adjoint generator G, define the actual conjugation path T_P(t)=exp(tG)Pexp(-tG). The formalization derives its derivative from the exponential power series and the product rule: T_P'(t)=exp(tG)(GP-PG)exp(-tG). Both exponential factors are proved unitary. Left and right multiplication by a unitary preserve the C-star norm. Therefore T_P'(t) = GP-PG , T_P(t)-T_P(s) ≤ |t-s| GP-PG . The second inequality follows from the mean value inequality in n…

    Exact mathematical passage
    
    T_P'(t)=\exp(tG)(GP-PG)\exp(-tG).
    
t_wUse in source · 2 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 802

    We call a recovery complete when it is a Kraus map R(X)=∑_jK_jXK_j^*, ∑_jK_j^*K_j=I. The family is exactly correctable when one such recovery works for every coherent error combination A_w=∑_aw_aE_a: for every w there is a real t_w≥0, independent of the logical input, such that PXP=X Longrightarrow R(A_wXA_w^*)=t_wX. The coefficient is an unnormalized weight. It is not necessarily a probability for an arbitrary matrix A_w.

    Exact mathematical passage
    t_w\ge0
t_\varepsilonUse in source · 4 passages

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  • Use in source · monograph_atlas.tex, line 738

    4 · (0,32,32,64) · 25/16 · 20 · 8/5 These are unnormalized traces. Normalizing by N changes Z_N but leaves the logarithmic derivative at that fixed grid unchanged. xfigheat_limits headThe theorem uses two separate choices For each ε>0, first choose a fixed positive time t_ε so that the continuum torus dimension differs from one by less than ε/2. Then choose N_ε so that every N≥ N_ε differs from that continuum value by less than ε/2 at the same time. This proves one controlled intermediate time f…

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    t_\varepsilon
\operatorname{Tr}Use in source · 1 passage

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  • Use in source · trace_topology.tex, line 5

    A_n _1=TrA_n=1; draw[->] (4.7,1.9)--(6.7,1.9);node[font=small] at (6,0.45) positive trace-class control: norm convergence alone does not preserve a trace;

    Exact mathematical passage
    \|A_n\|_1=\operatorname{Tr}A_n=1
\trUse in source · 5 passages

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  • Use in source · Read passage · 03_supplement_01.tex, line 79

    Measurements: source Theorem 7.1. For finite complex matrices, define packet dephasing by D_P(X)=∑_aP_aXP_a. The code proves idempotence and trace duality: D_P( D_P(X))= D_P(X), tr( D_P(E)ρ)=tr(E D_P(ρ)). Trace duality follows term by term from cyclicity: tr(P_aEP_aρ)=tr(EP_aρ P_a). Therefore an effect that is diagonal in the packets, D_P(E)=E, satisfies tr(Eρ)=tr(E D_P(ρ)). The proof holds for arbitrary finite complex matrices E and ρ. Density matrices and positive measurement effects are valid…

    Exact mathematical passage
    
    \deph(\deph(X))=\deph(X),\qquad
    \tr\bigl(\deph(E)\rho\bigr)=\tr\bigl(E\deph(\rho)\bigr).
    
\Tr_AUse in source · 1 passage

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  • Use in source · Read passage · 01_finite_core.tex, line 137

    [Local orbit and Schmidt rank] Let ψ∈ H_A⊗ H_B, with dim H_A=d_A≥1, and let r be its Schmidt rank. The reduced positive operator on B is ρ_B=Tr_A(ketψbraψ). Normalization of ψ does not affect its support. Then dimspan{(A⊗ I_B)ψ:A∈ M_d_A( C)} =d_A r. In particular, local operators on A generate the complete bipartite Hilbert space exactly when the reduced state on B has full support.

    Exact mathematical passage
    \rho_B=\Tr_A(\ket\psi\bra\psi)
\Tr_{\rm out}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 1083

    labelstrong:standardfact:001 A linear map Φ:M_n( C)→ M_m( C) is completely positive exactly when it has a Kraus representation Φ(X)=∑_rK_rXK_r^*. It is trace preserving exactly when ∑_rK_r^*K_r=I. Equivalently, its Choi matrix J(Φ) = ∑_i,jΦ(ketibraj)⊗ketibraj is positive, and trace preservation is Tr_rm outJ(Φ)=I_rm in.

    Exact mathematical passage
    
    \Tr_{\rm out}J(\Phi)=I_{\rm in}.
    
uUse in source · 27 passages

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  • Use in source · monograph_atlas.tex, line 194

    ORS AND PROBABILITY BOUNDSTraditional edition: Theorem II.5.3, Corollary II.5.4. For a two-level system, choose H=ε X, P=ket0bra0, and Q=I-P. Direct exponentiation gives e^- i tH=cos(ε t)I- isin(ε t)X, normQe^- i tHP=|sin(ε t)|, norm[H,P]=|ε|. The general commutator estimate becomes the elementary bound |sin u|≤ |u|. Unitarity also bounds the amplitude by one. vfigleakage headFrom a norm to a probability For this initial state, the escape probability is sin^2(ε t), not |sin(ε t)|. Consequently P…

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    |\sin u|\le |u|
U^*Use in source · 23 passages

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  • Use in source · monograph_atlas.tex, line 217

    1 · 0. Since U^*dot U=J, the coordinate Hamiltonian is H_rm frame=- i J=mat0 · i

    Exact mathematical passage
    U^*\dot U=J
U_1Use in source · 7 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 276

    Let U=U_mU_m-1⋯ U_1 be a circuit with m≥1, and let {P_α} be a complete packet system. For the empty circuit m=0, set U=I. Its boundary block is P_β P_α=δ_βαP_α.

    Exact mathematical passage
    
    U=U_mU_{m-1}\cdots U_1
    
u_aUse in source · 3 passages

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  • Use in source · monograph_atlas.tex, line 430

    splayed T happens also to have nonnegative entries and column sums one. Conjugate by the unitary Z. The spectrum and positivity of the quadratic form are preserved, but both off-diagonal entries become -1/4. Thus positivity as an operator is not entrywise positivity and does not by itself give a Markov interpretation. headA useful finite positive kernel For this nonnegative H, vectors u_a and times t_a≥0 satisfy ∑_a,b⟨ u_a,e^-(t_a+t_b)Hu_b⟩ = ∑_a e^-t_aHu_a ^2≥0. The factorization makes positivi…

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    u_a
U_{ar}Use in source · 2 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 843

    textitSufficiency. Diagonalize C=Udiag(λ_r)U^* with U unitary and λ_r≥0. Define compressed transformed errors F_r=∑_aU_arE_aP. Then F_rP=F_r and F_r^*F_s=λ_rδ_rsP. If λ_r=0, F_r^*F_r=0 forces F_r=0. For positive eigenvalues only, set V_r=F_r/sqrtλ_r. These satisfy V_rP=V_r, V_r^*V_s=δ_rsP. Let S=∑_λ_r>0V_rV_r^*. Orthogonality makes S an orthogonal projector. Use the recovery branches K_r=V_r^*, K_unused=I-S. They are complete on the whole ambient space because ∑_rK_r^*K_r+K_unused^*K_unused =S+(…

    Exact mathematical passage
    
    F_r=\sum_aU_{ar}E_aP.
    
U_bUse in source · 1 passage

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  • Use in source · Read passage · 03_supplement_06.tex, line 49

    Smooth overlap maps and rank. The coordinate transition is g_ab(x)=A_b(x)B_a(x). It is smooth on U_a∩ U_b, agrees with the actual change between local homeomorphisms, and satisfies g_aa=I, g_bcg_ab=g_ac. A continuous linear equivalence between E_a and E_x also gives local constancy of fiber dimension. No single constant rank across disconnected components is assumed.

    Exact mathematical passage
    U_a\cap U_b
u_bUse in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 431

    nnegative entries and column sums one. Conjugate by the unitary Z. The spectrum and positivity of the quadratic form are preserved, but both off-diagonal entries become -1/4. Thus positivity as an operator is not entrywise positivity and does not by itself give a Markov interpretation. headA useful finite positive kernel For this nonnegative H, vectors u_a and times t_a≥0 satisfy ∑_a,b⟨ u_a,e^-(t_a+t_b)Hu_b⟩ = ∑_a e^-t_aHu_a ^2≥0. The factorization makes positivity transparent. It remains a fini…

    Exact mathematical passage
    
    \sum_{a,b}\langle u_a,e^{-(t_a+t_b)H}u_b\rangle
    =\left\|\sum_a e^{-t_aH}u_a\right\|^2\ge0.
    
U_{ba}Use in source · 7 passages

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  • Use in source · monograph_atlas.tex, line 159

    The packetwise unitarity identity is likewise an operator identity, including the off-diagonal cancellations: ∑_b U_ba^*U_bc=δ_acP_a, U_ba=P_bUP_a. It cannot be replaced by the assertion that every path individually has unit norm. The exact checks verify all four choices of a,c for the two rank-one packets, as well as the two path products leading to the opposite output.

    Exact mathematical passage
    
    \sum_b U_{ba}^*U_{bc}=\delta_{ac}P_a,
    \qquad U_{ba}=P_bUP_a.
    
U_{ba}^*Use in source · 3 passages

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  • Use in source · monograph_atlas.tex, line 159

    The packetwise unitarity identity is likewise an operator identity, including the off-diagonal cancellations: ∑_b U_ba^*U_bc=δ_acP_a, U_ba=P_bUP_a. It cannot be replaced by the assertion that every path individually has unit norm. The exact checks verify all four choices of a,c for the two rank-one packets, as well as the two path products leading to the opposite output.

    Exact mathematical passage
    
    \sum_b U_{ba}^*U_{bc}=\delta_{ac}P_a,
    \qquad U_{ba}=P_bUP_a.
    
U_{bc}Use in source · 5 passages

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  • Use in source · monograph_atlas.tex, line 159

    The packetwise unitarity identity is likewise an operator identity, including the off-diagonal cancellations: ∑_b U_ba^*U_bc=δ_acP_a, U_ba=P_bUP_a. It cannot be replaced by the assertion that every path individually has unit norm. The exact checks verify all four choices of a,c for the two rank-one packets, as well as the two path products leading to the opposite output.

    Exact mathematical passage
    
    \sum_b U_{ba}^*U_{bc}=\delta_{ac}P_a,
    \qquad U_{ba}=P_bUP_a.
    
U_{da}Use in source · 1 passage

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  • Use in source · Read passage · 03_supplement_01.tex, line 35

    Adjoint conservation: source Theorem 4.2. Assume a star operation with P_a^*=P_a. Then (U_ba)^*=P_aU^*P_b. The two checked conservation laws are U^*U=1 · Longrightarrow ∑_b(U_ba)^*U_bc=δ_acP_a, UU^*=1 · Longrightarrow ∑_aU_ba(U_da)^*=δ_bdP_b. For the first law, expand each corner, collapse P_b^2 and sum: ∑_bP_aU^*P_bUP_c =P_aU^*(∑_bP_b)UP_c=P_aP_c. The second law follows by the analogous calculation and has its own formal proof. For complex matrices, the adjoint is the conjugate transpose. The o…

    Exact mathematical passage
    
    U^*U=1&\quad\Longrightarrow\quad
    \sum_b(U_{ba})^*U_{bc}=\delta_{ac}P_a,\\
    UU^*=1&\quad\Longrightarrow\quad
    \sum_aU_{ba}(U_{da})^*=\delta_{bd}P_b.
    
U_{da}^*Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 424

    [Packet unitarity identities] If U is unitary and U_ba=P_bUP_a, then ∑_bU_ba^*U_bc=δ_acP_a and ∑_aU_baU_da^*=δ_bdP_b.

    Exact mathematical passage
    
    \sum_aU_{ba}U_{da}^*=\delta_{bd}P_b.
    
u_jUse in source · 2 passages

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  • Use in source · monograph_atlas.tex, line 716

    trivial excited spectra, a uniform exponential rate needs a common positive lower bound on the gap. Ground multiplicity does not cause a problem: P_0 selects the entire eigenspace at the minimum energy. For a Hamiltonian whose minimum is E_0≠0, the normalized transfer is e^-t(H-E_0I) before taking the limit. headPositivity is retained at several Euclidean times For arbitrary vectors u_j and nonnegative integer times n_j, the reflected kernel obeys ∑_j,k⟨ u_j,T^n_j+n_ku_k⟩ = ∑_jT^n_ju_j ^2. This …

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    u_j
u_kUse in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 717

    tive lower bound on the gap. Ground multiplicity does not cause a problem: P_0 selects the entire eigenspace at the minimum energy. For a Hamiltonian whose minimum is E_0≠0, the normalized transfer is e^-t(H-E_0I) before taking the limit. headPositivity is retained at several Euclidean times For arbitrary vectors u_j and nonnegative integer times n_j, the reflected kernel obeys ∑_j,k⟨ u_j,T^n_j+n_ku_k⟩ = ∑_jT^n_ju_j ^2. This is a finite Gram factorization. The retained run checks the integer sem…

    Exact mathematical passage
    
    \sum_{j,k}\langle u_j,T^{n_j+n_k}u_k\rangle
    =\left\|\sum_jT^{n_j}u_j\right\|^2.
    
U_mUse in source · 7 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 276

    Let U=U_mU_m-1⋯ U_1 be a circuit with m≥1, and let {P_α} be a complete packet system. For the empty circuit m=0, set U=I. Its boundary block is P_β P_α=δ_βαP_α.

    Exact mathematical passage
    
    U=U_mU_{m-1}\cdots U_1
    
U_{m-1}Use in source · 2 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 276

    Let U=U_mU_m-1⋯ U_1 be a circuit with m≥1, and let {P_α} be a complete packet system. For the empty circuit m=0, set U=I. Its boundary block is P_β P_α=δ_βαP_α.

    Exact mathematical passage
    
    U=U_mU_{m-1}\cdots U_1
    
u_NUse in source · 3 passages

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  • Use in source · monograph_atlas.tex, line 283

    n·σ). This is a smooth rank-one orthogonal projector. The intrinsic curvature is the endomorphism-valued two-form P( d Pwedge d P)P. With the paper's scalar convention, its component is F_θϕ=- iTr (P[∂_θ P,∂_ϕ P]) =frac12sinθ. vfigbloch_curvature headA local frame gives the same answer Away from the south pole, use u_N=(cos(θ/2),e^ iϕsin(θ/2))^T. Then P=u_Nu_N^* and the scalar one-form is A_N=- i u_N^* d u_N=frac1-cosθ2 dϕ, d A_N=frac12sinθ dθwedge dϕ. Thus the curvature flux through the cap 0≤θ…

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    u_N=(\cos(\theta/2),e^{\ii\phi}\sin(\theta/2))^T
u_N^*Use in source · 2 passages

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  • Use in source · monograph_atlas.tex, line 283

    ojector. The intrinsic curvature is the endomorphism-valued two-form P( d Pwedge d P)P. With the paper's scalar convention, its component is F_θϕ=- iTr (P[∂_θ P,∂_ϕ P]) =frac12sinθ. vfigbloch_curvature headA local frame gives the same answer Away from the south pole, use u_N=(cos(θ/2),e^ iϕsin(θ/2))^T. Then P=u_Nu_N^* and the scalar one-form is A_N=- i u_N^* d u_N=frac1-cosθ2 dϕ, d A_N=frac12sinθ dθwedge dϕ. Thus the curvature flux through the cap 0≤θ≤θ_0 is π(1-cosθ_0). At θ_0=π/3, it is exactl…

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    P=u_Nu_N^*
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  • Use in source · Read passage · 02_strengthened.tex, line 485

    [Charge pruning of circuit paths] Suppose every gate has a finite charge decomposition U_r=∑_qU_r^(q), SU_r^(q)S^*=ω^qU_r^(q). A term with gate charges q_1,…,q_m can contribute from source charge a_0 only to target charge a_m=a_0+q_1+⋯+q_m. Every packet path violating one of the intermediate charge updates vanishes.

    Exact mathematical passage
    
    U_r=\sum_qU_r^{(q)},
    \qquad
    SU_r^{(q)}S^*=\omega^qU_r^{(q)}.
    
U_r^{(q)}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 485

    [Charge pruning of circuit paths] Suppose every gate has a finite charge decomposition U_r=∑_qU_r^(q), SU_r^(q)S^*=ω^qU_r^(q). A term with gate charges q_1,…,q_m can contribute from source charge a_0 only to target charge a_m=a_0+q_1+⋯+q_m. Every packet path violating one of the intermediate charge updates vanishes.

    Exact mathematical passage
    
    U_r=\sum_qU_r^{(q)},
    \qquad
    SU_r^{(q)}S^*=\omega^qU_r^{(q)}.
    
U_{\beta\alpha}Use in source · 2 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 301

    [Packetwise unitarity conservation] If U is unitary and U_βα=P_β UP_α, then ∑_β U_βα^*U_βγ = δ_αγP_α. Similarly, ∑_α U_βαU_δα^* = δ_βδP_β.

    Exact mathematical passage
    U_{\beta\alpha}=P_\beta UP_\alpha
U_{\beta\alpha}^*Use in source · 2 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 302

    [Packetwise unitarity conservation] If U is unitary and U_βα=P_β UP_α, then ∑_β U_βα^*U_βγ = δ_αγP_α. Similarly, ∑_α U_βαU_δα^* = δ_βδP_β.

    Exact mathematical passage
    
    \boxed{
    \sum_\beta U_{\beta\alpha}^*U_{\beta\gamma}
    =
    \delta_{\alpha\gamma}P_\alpha.
    }
    
U_{\beta\gamma}Use in source · 2 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 302

    [Packetwise unitarity conservation] If U is unitary and U_βα=P_β UP_α, then ∑_β U_βα^*U_βγ = δ_αγP_α. Similarly, ∑_α U_βαU_δα^* = δ_βδP_β.

    Exact mathematical passage
    
    \boxed{
    \sum_\beta U_{\beta\alpha}^*U_{\beta\gamma}
    =
    \delta_{\alpha\gamma}P_\alpha.
    }
    
U_\gammaUse in source · 2 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 410

    For a packet path γ=(a_0,a_1,…,a_m), write U_γ = P_a_mU_mP_a_m-1 ⋯ P_a_1U_1P_a_0.

    Exact mathematical passage
    
    U_\gamma
    =
    P_{a_m}U_mP_{a_{m-1}}
    \cdots
    P_{a_1}U_1P_{a_0}.
    
U_{\delta\alpha}^*Use in source · 1 passage

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  • Use in source · Read passage · 01_finite_core.tex, line 310

    [Packetwise unitarity conservation] If U is unitary and U_βα=P_β UP_α, then ∑_β U_βα^*U_βγ = δ_αγP_α. Similarly, ∑_α U_βαU_δα^* = δ_βδP_β.

    Exact mathematical passage
    
    \sum_\alpha U_{\beta\alpha}U_{\delta\alpha}^*
    =
    \delta_{\beta\delta}P_\beta.
    
\mathrm{unused}Use in source · 2 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 851

    efine compressed transformed errors F_r=∑_aU_arE_aP. Then F_rP=F_r and F_r^*F_s=λ_rδ_rsP. If λ_r=0, F_r^*F_r=0 forces F_r=0. For positive eigenvalues only, set V_r=F_r/sqrtλ_r. These satisfy V_rP=V_r, V_r^*V_s=δ_rsP. Let S=∑_λ_r>0V_rV_r^*. Orthogonality makes S an orthogonal projector. Use the recovery branches K_r=V_r^*, K_unused=I-S. They are complete on the whole ambient space because ∑_rK_r^*K_r+K_unused^*K_unused =S+(I-S)^2=I. The inverse unitary change of coordinates reconstructs each E_aP…

    Exact mathematical passage
    
    K_r=V_r^*,\qquad K_{\mathrm{unused}}=I-S.
    
V'Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 862

    [Nonabelian packet connection] The one form with matrix values A=V^* d V is skew adjoint. Under a frame change V'=VG, where G(x)∈ U(r), A' = G^* A G+G^* d G. Its curvature F= d A+ Awedge A satisfies F=V^*( d Pwedge d P)V.

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    V'=VG
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  • Use in source · monograph_atlas.tex, line 370

    main inside the original code, so the previous syndrome partition reports no bit flip. frac3ket000+4ket1115 ⟼ frac3ket000-4ket1115. The populations are unchanged, but the relative phase is not. vfiglogical_error Let V be the code isometry with columns ket000,ket111. For the proposed error family {I,Z_1}, its off-diagonal error compression is V^*I^*Z_1V=mat1 · 0 0 · -1. This matrix is not cI for any scalar c. Thus the Knill--Laflamme condition fails for that family. Its trace is zero even though …

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    V^*I^*Z_1V=\mat{1&0\\0&-1}.
    
v^*Use in source · 1 passage

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  • Use in source · euclidean.tex, line 22

    spectrum {1,1/2}.; node[font=small,align=center,font=small] at (7,0.4) Positive-definite operator: v^*Tv>0 for v≠0. Not an entrywise test.;

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    v^*Tv>0
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  • Use in source · cyclic_four.tex, line 44

    anchor=east,font=scriptsize] at (0.85,1.2) site 3; node[font=small,align=center,font=scriptsize] at (1.4,4.23) j=0; node[font=small,align=center,font=scriptsize] at (2.2,4.23) j=1; node[font=small,align=center,font=scriptsize] at (3,4.23) j=2; node[font=small,align=center,font=scriptsize] at (3.8,4.23) j=3; node[font=small,align=center,font=small] at (8.05,3.8) S v_0=1v_0; node[font=small,align=center,font=small] at (11.85,3.8) P_0=v_0v_0^*; node[font=small,align=center,font=small] at (8.05,2.95…

    Exact mathematical passage
    S v_0=1v_0
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  • Use in source · cyclic_four.tex, line 45

    gn=center,font=scriptsize] at (1.4,4.23) j=0; node[font=small,align=center,font=scriptsize] at (2.2,4.23) j=1; node[font=small,align=center,font=scriptsize] at (3,4.23) j=2; node[font=small,align=center,font=scriptsize] at (3.8,4.23) j=3; node[font=small,align=center,font=small] at (8.05,3.8) S v_0=1v_0; node[font=small,align=center,font=small] at (11.85,3.8) P_0=v_0v_0^*; node[font=small,align=center,font=small] at (8.05,2.95) S v_1=iv_1; node[font=small,align=center,font=small] at (11.85,2.95)…

    Exact mathematical passage
    P_0=v_0v_0^*
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  • Use in source · monograph_atlas.tex, line 610

    0 · 0 · 1, WcW^*=diag(1,0,0), (F_1,F_2,F_3)=(P,0,0). xfiggram headNormalize only positive eigenvalues The positive branch has V_1=P as an isometry on the code, and syndrome support Q=P. No factor λ^-1/2 is formed on either zero branch: those branches vanish on the code. Treating them as extra recoverable packets would divide by zero.

    Exact mathematical passage
    V_1=P
v_1Use in source · 4 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 1713

    [Positive definite quantum memory] The kernel K(t-s) is positive definite. For times t_1,…,t_m and retained vectors v_1,…,v_m, ∑_j,k=1^m ipv_jK(t_j-t_k)v_k ≥0.

    Exact mathematical passage
    v_1,\ldots,v_m
v_1^*Use in source · 1 passage

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  • Use in source · cyclic_four.tex, line 47

    ,font=scriptsize] at (3,4.23) j=2; node[font=small,align=center,font=scriptsize] at (3.8,4.23) j=3; node[font=small,align=center,font=small] at (8.05,3.8) S v_0=1v_0; node[font=small,align=center,font=small] at (11.85,3.8) P_0=v_0v_0^*; node[font=small,align=center,font=small] at (8.05,2.95) S v_1=iv_1; node[font=small,align=center,font=small] at (11.85,2.95) P_1=v_1v_1^*; node[font=small,align=center,font=small] at (8.05,2.1) S v_2=-1v_2; node[font=small,align=center,font=small] at (11.85,2.1) …

    Exact mathematical passage
    P_1=v_1v_1^*
v_2Use in source · 2 passages

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  • Use in source · cyclic_four.tex, line 48

    scriptsize] at (3.8,4.23) j=3; node[font=small,align=center,font=small] at (8.05,3.8) S v_0=1v_0; node[font=small,align=center,font=small] at (11.85,3.8) P_0=v_0v_0^*; node[font=small,align=center,font=small] at (8.05,2.95) S v_1=iv_1; node[font=small,align=center,font=small] at (11.85,2.95) P_1=v_1v_1^*; node[font=small,align=center,font=small] at (8.05,2.1) S v_2=-1v_2; node[font=small,align=center,font=small] at (11.85,2.1) P_2=v_2v_2^*; node[font=small,align=center,font=small] at (8.05,1.25)…

    Exact mathematical passage
    S v_2=-1v_2
v_2^*Use in source · 1 passage

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  • Use in source · cyclic_four.tex, line 49

    ll] at (8.05,3.8) S v_0=1v_0; node[font=small,align=center,font=small] at (11.85,3.8) P_0=v_0v_0^*; node[font=small,align=center,font=small] at (8.05,2.95) S v_1=iv_1; node[font=small,align=center,font=small] at (11.85,2.95) P_1=v_1v_1^*; node[font=small,align=center,font=small] at (8.05,2.1) S v_2=-1v_2; node[font=small,align=center,font=small] at (11.85,2.1) P_2=v_2v_2^*; node[font=small,align=center,font=small] at (8.05,1.25) S v_3=- iv_3; node[font=small,align=center,font=small] at (11.85,1.…

    Exact mathematical passage
    P_2=v_2v_2^*
v_3Use in source · 2 passages

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  • Use in source · cyclic_four.tex, line 50

    at (11.85,3.8) P_0=v_0v_0^*; node[font=small,align=center,font=small] at (8.05,2.95) S v_1=iv_1; node[font=small,align=center,font=small] at (11.85,2.95) P_1=v_1v_1^*; node[font=small,align=center,font=small] at (8.05,2.1) S v_2=-1v_2; node[font=small,align=center,font=small] at (11.85,2.1) P_2=v_2v_2^*; node[font=small,align=center,font=small] at (8.05,1.25) S v_3=- iv_3; node[font=small,align=center,font=small] at (11.85,1.25) P_3=v_3v_3^*; node[font=small,align=center,font=scriptsize] at (8.8…

    Exact mathematical passage
    S v_3=- iv_3
v_3^*Use in source · 1 passage

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  • Use in source · cyclic_four.tex, line 51

    at (8.05,2.95) S v_1=iv_1; node[font=small,align=center,font=small] at (11.85,2.95) P_1=v_1v_1^*; node[font=small,align=center,font=small] at (8.05,2.1) S v_2=-1v_2; node[font=small,align=center,font=small] at (11.85,2.1) P_2=v_2v_2^*; node[font=small,align=center,font=small] at (8.05,1.25) S v_3=- iv_3; node[font=small,align=center,font=small] at (11.85,1.25) P_3=v_3v_3^*; node[font=small,align=center,font=scriptsize] at (8.8,0.12) Each column has four entries of magnitude 1/2.;

    Exact mathematical passage
    P_3=v_3v_3^*
V_aUse in source · 9 passages

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  • Use in source · Read passage · 03_supplement_04.tex, line 94

    A constructive and total syndrome recovery. Let P be an orthogonal code projector. The input certificate consists of a finite family V_a satisfying V_aP=V_a, V_a^*V_b=δ_abP. These hypotheses state that the operators are partial isometries with orthogonal syndromes. The next supplement derives such a family from arbitrary Knill--Laflamme Gram data.

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    V_a
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  • Use in source · Read passage · 03_supplement_03.tex, line 53

    An independent definition of Schmidt rank. The source defines Schmidt rank as the least number of summands that are product vectors. A decomposition of length s is the concrete equality C_ij=∑_a=1^su_a(i)v_a(j). It factors C=UV through an s-dimensional intermediate space, so rank C≤ s. Conversely, choose a basis of the row space of C. Expanding each row in this basis constructs a decomposition with exactly rank C product terms. Thus r(ψ)=rank C. The definition uses a least natural number, and th…

    Exact mathematical passage
    
    C_{ij}=\sum_{a=1}^{s}u_a(i)v_a(j).
    
V_a^*Use in source · 7 passages

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  • Use in source · Read passage · 03_supplement_04.tex, line 95

    A constructive and total syndrome recovery. Let P be an orthogonal code projector. The input certificate consists of a finite family V_a satisfying V_aP=V_a, V_a^*V_b=δ_abP. These hypotheses state that the operators are partial isometries with orthogonal syndromes. The next supplement derives such a family from arbitrary Knill--Laflamme Gram data.

    Exact mathematical passage
    
    V_aP=V_a,
    \qquad
    V_a^*V_b=\delta_{ab}P.
    
V_bUse in source · 1 passage

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  • Use in source · Read passage · 03_supplement_04.tex, line 95

    A constructive and total syndrome recovery. Let P be an orthogonal code projector. The input certificate consists of a finite family V_a satisfying V_aP=V_a, V_a^*V_b=δ_abP. These hypotheses state that the operators are partial isometries with orthogonal syndromes. The next supplement derives such a family from arbitrary Knill--Laflamme Gram data.

    Exact mathematical passage
    
    V_aP=V_a,
    \qquad
    V_a^*V_b=\delta_{ab}P.
    
V_b^*Use in source · 1 passage

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  • Use in source · Read passage · 03_supplement_04.tex, line 122

    Exact correction, including coherent errors. For every operator supported on the code, Pρ P=ρ, the central identity is R(V_aρ V_b^*)=δ_abρ. Consequently normalized mixtures satisfy R (∑_ap_aV_aρ V_a^*)=ρ when ∑_ap_a=1. The identity is algebraic and is proved for complex weights. Physical mixtures use the nonnegative real case. For a coherent error E_z=∑_a z_aV_a, the calculation of the cross terms yields R(E_zρ E_z^*)=(∑_a z_aoverlinez_a)ρ. Thus the same map also corrects normalized coherent sup…

    Exact mathematical passage
    
    \boxed{\mathcal R(V_a\rho V_b^*)=\delta_{ab}\rho.}
    
V_{ca}Use in source · 1 passage

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  • Use in source · Read passage · 03_supplement_01.tex, line 12

    0, · a≠ b, ∑_a∈ IP_a=1. Adjoint conditions are added when needed. For an operator U, define the transfer corner U_ba=P_bUP_a. The target index comes first. Completeness and distributivity give ∑_b,aU_ba=U, (UV)_ba=∑_c U_bcV_ca. The second identity uses P_c^2=P_c when adjacent transfer corners are multiplied.

    Exact mathematical passage
    
    \sum_{b,a}U_{ba}=U,\qquad
    (UV)_{ba}=\sum_c U_{bc}V_{ca}.
    
V_jUse in source · 8 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 1327

    syndrome construction] Assume the Knill Laflamme identities. Then the coefficient matrix c is positive semidefinite. Choose a unitary matrix W such that WcW^*=diag(λ_1,…,λ_r), λ_j≥0, and define F_j=∑_aoverlineW_jaE_a. For every j with λ_j>0, the operator V_j=λ_j^-1/2F_jP is an isometry from the code into H. Its range projector Q_j=V_jV_j^* is a syndrome packet, and the nonzero Q_j are pairwise orthogonal.

    Exact mathematical passage
    
    V_j=\lambda_j^{-1/2}F_jP
    
v_jUse in source · 10 passages

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  • Use in source · monograph_atlas.tex, line 93

    vpage6Four phases resolve a cyclic shiftCHARACTER PROJECTORS YOU CAN MULTIPLYTraditional edition: Corollary II.3.3. On four sites, let Sket k=ketk+1bmod4 and let ω= i. The character projectors are the exact matrices P_j=frac14∑_r=0^3 i^-jrS^r, v_j(k)=frac12 i^-jk, P_j=v_jv_j^*. All entries belong to the Gaussian rationals. Thus no approximation to a root of unity is needed in this model. vfigcyclic_four headReading the columns Each column v_j is a normalized wave around the four sites. Advancing…

    Exact mathematical passage
    
    P_j=\frac14\sum_{r=0}^3\ii^{-jr}S^r,
    \qquad v_j(k)=\frac12\ii^{-jk},\qquad P_j=v_jv_j^*.
    
V_j^*Use in source · 6 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 1331

    the Knill Laflamme identities. Then the coefficient matrix c is positive semidefinite. Choose a unitary matrix W such that WcW^*=diag(λ_1,…,λ_r), λ_j≥0, and define F_j=∑_aoverlineW_jaE_a. For every j with λ_j>0, the operator V_j=λ_j^-1/2F_jP is an isometry from the code into H. Its range projector Q_j=V_jV_j^* is a syndrome packet, and the nonzero Q_j are pairwise orthogonal.

    Exact mathematical passage
    
    Q_j=V_jV_j^*
    
v_j^*Use in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 93

    vpage6Four phases resolve a cyclic shiftCHARACTER PROJECTORS YOU CAN MULTIPLYTraditional edition: Corollary II.3.3. On four sites, let Sket k=ketk+1bmod4 and let ω= i. The character projectors are the exact matrices P_j=frac14∑_r=0^3 i^-jrS^r, v_j(k)=frac12 i^-jk, P_j=v_jv_j^*. All entries belong to the Gaussian rationals. Thus no approximation to a root of unity is needed in this model. vfigcyclic_four headReading the columns Each column v_j is a normalized wave around the four sites. Advancing…

    Exact mathematical passage
    
    P_j=\frac14\sum_{r=0}^3\ii^{-jr}S^r,
    \qquad v_j(k)=\frac12\ii^{-jk},\qquad P_j=v_jv_j^*.
    
v_kUse in source · 9 passages

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  • Use in source · monograph_atlas.tex, line 688

    ts memory kernel is K(t)=frac925e^- i t+frac1625e^-2 i t, K(0)=1. Each oscillatory coefficient is positive although K(t) need not be real or pointwise nonnegative. At t=π/2, it equals -16/25-9 i/25. xfigmemory_positive headPositive definite means a matrix test at arbitrary times For retained scalars v_j and real times t_j, the structural identity is ∑_j,koverline v_jK(t_j-t_k)v_k = ∑_k e^ i t_kDB^*v_k ^2≥0. The exact worked check specializes to t=(0,π/2,π) and v=(1,2,-1). Its phases lie in QQ( i…

    Exact mathematical passage
    
    \sum_{j,k}\overline v_jK(t_j-t_k)v_k
    =\left\|\sum_k e^{\ii t_kD}B^*v_k\right\|^2\geq0.
    
v_mUse in source · 2 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 1713

    [Positive definite quantum memory] The kernel K(t-s) is positive definite. For times t_1,…,t_m and retained vectors v_1,…,v_m, ∑_j,k=1^m ipv_jK(t_j-t_k)v_k ≥0.

    Exact mathematical passage
    v_1,\ldots,v_m
V_nUse in source · 2 passages

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  • Use in source · Read passage · 03_supplement_02.tex, line 5

    For n≥ 0, let A_n=( Z/2 Z)^{0,…,n-1}, V_n={v:A_n→ C}. For an address a∈ A_n, define the standard coordinate vector ket a(x)=1 · x=a,

    Exact mathematical passage
    
     A_n=(\mathbb Z/2\mathbb Z)^{\{0,\ldots,n-1\}},\qquad
     V_n=\{v:A_n\to\C\}.
    
V_sUse in source · 2 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 847

    textitSufficiency. Diagonalize C=Udiag(λ_r)U^* with U unitary and λ_r≥0. Define compressed transformed errors F_r=∑_aU_arE_aP. Then F_rP=F_r and F_r^*F_s=λ_rδ_rsP. If λ_r=0, F_r^*F_r=0 forces F_r=0. For positive eigenvalues only, set V_r=F_r/sqrtλ_r. These satisfy V_rP=V_r, V_r^*V_s=δ_rsP. Let S=∑_λ_r>0V_rV_r^*. Orthogonality makes S an orthogonal projector. Use the recovery branches K_r=V_r^*, K_unused=I-S. They are complete on the whole ambient space because ∑_rK_r^*K_r+K_unused^*K_unused =S+(…

    Exact mathematical passage
    
    V_rP=V_r,\qquad V_r^*V_s=\delta_{rs}P.
    
V_\muUse in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 225

    Complete reducibility gives a unitary decomposition H ≅ ⊕_μ∈widehat G V_μ⊗ M_μ, U(g) ≅ ⊕_μ π_μ(g)⊗ I_M_μ. On the μ summand, the displayed average is central in the irreducible representation π_μ, so it is a scalar by Schur's lemma. Taking its trace and applying character orthogonality shows that the scalar is one when μ=λ and zero otherwise. The asserted identities follow on the direct sum.

    Exact mathematical passage
    
    \Hcal
    \cong
    \bigoplus_{\mu\in\widehat G}
    V_\mu\otimes M_\mu,
    \qquad
    U(g)
    \cong
    \bigoplus_\mu
    \pi_\mu(g)\otimes I_{M_\mu}.
    
V_\ellUse in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 1349

    For z∈ C^r, let F_z=∑_az_aE_a. Then PF_z^*F_zP=(z^*cz)P≥0, so c≥0. The unitary change of error coordinates gives PF_j^*F_ℓ P = λ_jδ_jℓP. Thus V_j^*V_ℓ=δ_jℓP. Each V_j is an isometry on P H, and distinct ranges are orthogonal. Their range projectors are therefore pairwise orthogonal.

    Exact mathematical passage
    
    V_j^*V_\ell=\delta_{j\ell}P.
    
\operatorname{val}Use in source · 4 passages

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  • Use in source · Read passage · 03_supplement_03.tex, line 93

    Constructed cyclic character projectors. Let N>0 and let S be a unitary complex matrix with S^N=I. The implementation uses the standard additive character of Z/N Z and proves its expression through a root of unity: ω=exp(2π i/N), χ(r)=ω^val(r). Here val(r) is the canonical representative in {0,…,N-1}. The representation is constructed as ρ(r)=S^val(r). Reduction of exponents modulo N is proved from S^N=I, giving ρ(r+s)=ρ(r)ρ(s) and ρ(0)=I. The final matrix theorem derives the representation law …

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    \omega=\exp(2\pi i/N),\qquad
    \chi(r)=\omega^{\operatorname{val}(r)}.
    
WUse in source · 32 passages

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  • Use in source · monograph_atlas.tex, line 45

    vpage3One seed, eight addressesCYCLICITY DEPENDS ON THE GRAMMARTraditional edition: Proposition II.2.5. Start with ψ_0=ket000 and allow the three bit flip operators X_1,X_2,X_3. For a binary address a=(a_1,a_2,a_3), put W_a=X_1^a_1X_2^a_2X_3^a_3. W_aψ_0=keta_1a_2a_3. The drawing shows the actual eight states reached by these words. Dashed edges connect the two squares by changing the first bit. The other edges change one of the remaining bits. vfigaddresses headTwo different meanings of ``reach'…

    Exact mathematical passage
    
    W_a=X_1^{a_1}X_2^{a_2}X_3^{a_3}.
    \qquad W_a\psi_0=\ket{a_1a_2a_3}.
    
W^*Use in source · 6 passages

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  • Use in source · monograph_atlas.tex, line 603

    0 · 0 · 0, PE_a^*E_bP=c_abP. The errors are redundant rather than three distinct syndromes. A real unitary change of error coordinates gives W=mat3/5 · 4/5 · 0 -4/5 · 3/5 · 0 0 · 0 · 1, WcW^*=diag(1,0,0), (F_1,F_2,F_3)=(P,0,0). xfiggram headNormalize only positive eigenvalues The positive branch has V_1=P as an isometry on the code, and syndrome support Q=P. No factor λ^-1/2 is formed on either zero branch: those branches vanish on the code. Treating them as extra recoverable packets would divid…

    Exact mathematical passage
    
    W=\mat{3/5&4/5&0\\-4/5&3/5&0\\0&0&1},
    \quad WcW^*=\diag(1,0,0),
    \quad(F_1,F_2,F_3)=(P,0,0).
    
w^*Use in source · 3 passages

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  • Use in source · monograph_atlas.tex, line 338

    0 · 0 · 0 · 1. Its middle block has one negative eigenvalue. More concretely, the normalized vector w=(ket01-ket10)/sqrt2 satisfies w^*(id⊗ T)(ρ_rm Bell)w=-frac12. This exact negative value of the quadratic form certifies failure of positivity on the composite system. No numerical eigenvalue tolerance is needed. headWhy the Kraus form avoids this problem For every auxiliary dimension and positive X, each term (I⊗ K_a)X(I⊗ K_a)^* is positive. Their sum is positive as well. This argument explains …

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    w^*(\id\otimes\mathsf T)(\rho_{\rm Bell})w=-\frac12.
    
w^2Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 1727

    Set w=∑_k=1^m e^ i t_kDB^*v_k. Then norm w^2 = ∑_j,k ipB^*v_j e^- i(t_j-t_k)DB^*v_k = ∑_j,k ipv_jK(t_j-t_k)v_k.

    Exact mathematical passage
    
    \norm w^2
    =
    \sum_{j,k}
    \ip{B^*v_j}{\e^{-\ii(t_j-t_k)D}B^*v_k}
    =
    \sum_{j,k}
    \ip{v_j}{K(t_j-t_k)v_k}.
    
W_{011}Use in source · 1 passage

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  • Use in source · addresses.tex, line 33

    node[font=small,align=center] at (2.65,4.05) ket110; path[draw,fill=white] (5.53,3.75) rectangle (6.47,4.35); node[font=small,align=center] at (6,4.05) ket111; node[font=small,align=center,font=small] at (10.15,4.1) Three actual words; node[font=small,align=center,font=small] at (10.15,3.1) W_101=X_1X_3; node[font=small,align=center,font=small] at (10.15,2.2) W_011=X_2X_3; node[font=small,align=center,font=small] at (10.15,1.3) W_110=X_1X_2; node[font=small,align=center,font=small] at (6.65,0.1)…

    Exact mathematical passage
    W_{011}=X_2X_3
W_{101}Use in source · 1 passage

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  • Use in source · addresses.tex, line 32

    ,1.6) ket101; path[draw,fill=white] (2.18,3.75) rectangle (3.12,4.35); node[font=small,align=center] at (2.65,4.05) ket110; path[draw,fill=white] (5.53,3.75) rectangle (6.47,4.35); node[font=small,align=center] at (6,4.05) ket111; node[font=small,align=center,font=small] at (10.15,4.1) Three actual words; node[font=small,align=center,font=small] at (10.15,3.1) W_101=X_1X_3; node[font=small,align=center,font=small] at (10.15,2.2) W_011=X_2X_3; node[font=small,align=center,font=small] at (10.15,1.…

    Exact mathematical passage
    W_{101}=X_1X_3
W_{110}Use in source · 1 passage

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  • Use in source · addresses.tex, line 34

    hite] (5.53,3.75) rectangle (6.47,4.35); node[font=small,align=center] at (6,4.05) ket111; node[font=small,align=center,font=small] at (10.15,4.1) Three actual words; node[font=small,align=center,font=small] at (10.15,3.1) W_101=X_1X_3; node[font=small,align=center,font=small] at (10.15,2.2) W_011=X_2X_3; node[font=small,align=center,font=small] at (10.15,1.3) W_110=X_1X_2; node[font=small,align=center,font=small] at (6.65,0.1) dimSpan{W_aket000}=8;

    Exact mathematical passage
    W_{110}=X_1X_2
W_aUse in source · 6 passages

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  • Use in source · monograph_atlas.tex, line 45

    vpage3One seed, eight addressesCYCLICITY DEPENDS ON THE GRAMMARTraditional edition: Proposition II.2.5. Start with ψ_0=ket000 and allow the three bit flip operators X_1,X_2,X_3. For a binary address a=(a_1,a_2,a_3), put W_a=X_1^a_1X_2^a_2X_3^a_3. W_aψ_0=keta_1a_2a_3. The drawing shows the actual eight states reached by these words. Dashed edges connect the two squares by changing the first bit. The other edges change one of the remaining bits. vfigaddresses headTwo different meanings of ``reach'…

    Exact mathematical passage
    
    W_a=X_1^{a_1}X_2^{a_2}X_3^{a_3}.
    \qquad W_a\psi_0=\ket{a_1a_2a_3}.
    
w_aUse in source · 3 passages

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  • Use in source · monograph_atlas.tex, line 351

    II.8.4, Example II.8.8. Encode a qubit by ket0_L=ket000 and ket1_L=ket111. Let P project onto this code and take errors E_a∈{I,X_1,X_2,X_3}. Their images are four orthogonal rank-two packets Q_a=E_aPE_a^* that sum to the full identity. vfigsyndromes Use the logical state ψ=(3ket0_L+4ket1_L)/5 and channel probabilities w=(1,2,3,4)/10. The noisy state is ∑_aw_aE_aψψ^*E_a^*. A syndrome measurement returns label a with probability w_a, independent of the logical amplitudes. headThe recovery is an ac…

    Exact mathematical passage
    \sum_aw_aE_a\psi\psi^*E_a^*
W_\piUse in source · 2 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 804

    [Convergence of short packet rotations] Let (P_a(t)) be twice continuously differentiable on [0,T]. For a partition 0=t_0<t_1<⋯<t_n=T, let W_π = U( P(t_n), P(t_n-1)) ⋯ U( P(t_1), P(t_0)). For sufficiently fine partitions the factors are defined, and normW_π-W(T) ≤ C_Tabsπ for a constant depending on the packet path but not on the partition. Here the size of the partition is measured by its mesh, which is the length of its largest subinterval.

    Exact mathematical passage
    
    W_\pi
    =
    \Ucal\bigl(\Pcal(t_n),\Pcal(t_{n-1})\bigr)
    \cdots
    \Ucal\bigl(\Pcal(t_1),\Pcal(t_0)\bigr).
    
\widehat CUse in source · 3 passages

Search aliases: widehat C widehat

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  • Use in source · Read passage · 01_finite_core.tex, line 1198

    At one finite level, let widehat C_A be a finite family of matrix constraints, with fixed scalar structure coefficients, and let Π^phys be the orthogonal projector onto their exact common kernel. If the classical constraint algebra has structure coefficients f_AB^ C, define the anomaly operator A_AB = [widehat C_A,widehat C_B] -i∑_C f_AB^ Cwidehat C_C. Its physical packet is Π^phys A_ABΠ^phys. In this exact finite setting, widehat C_CΠ^phys=0 for every C. Associativity gives A_ABΠ^phys=0, Π^phys…

    Exact mathematical passage
    \widehat C_A
\widehat C_AUse in source · 2 passages

Search aliases: widehat C_A widehat

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  • Use in source · Read passage · 01_finite_core.tex, line 1198

    At one finite level, let widehat C_A be a finite family of matrix constraints, with fixed scalar structure coefficients, and let Π^phys be the orthogonal projector onto their exact common kernel. If the classical constraint algebra has structure coefficients f_AB^ C, define the anomaly operator A_AB = [widehat C_A,widehat C_B] -i∑_C f_AB^ Cwidehat C_C. Its physical packet is Π^phys A_ABΠ^phys. In this exact finite setting, widehat C_CΠ^phys=0 for every C. Associativity gives A_ABΠ^phys=0, Π^phys…

    Exact mathematical passage
    \widehat C_A
\widehat C_BUse in source · 1 passage

Search aliases: widehat C_B widehat

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  • Use in source · Read passage · 01_finite_core.tex, line 1199

    At one finite level, let widehat C_A be a finite family of matrix constraints, with fixed scalar structure coefficients, and let Π^phys be the orthogonal projector onto their exact common kernel. If the classical constraint algebra has structure coefficients f_AB^ C, define the anomaly operator A_AB = [widehat C_A,widehat C_B] -i∑_C f_AB^ Cwidehat C_C. Its physical packet is Π^phys A_ABΠ^phys. In this exact finite setting, widehat C_CΠ^phys=0 for every C. Associativity gives A_ABΠ^phys=0, Π^phys…

    Exact mathematical passage
    
    \boxed{
    \mathfrak A_{AB}
    =
    [\widehat C_A,\widehat C_B]
    -i\sum_C f_{AB}^{\ \ C}\widehat C_C.
    }
    
\widehat C_CUse in source · 2 passages

Search aliases: widehat C_C widehat

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  • Use in source · Read passage · 01_finite_core.tex, line 1199

    At one finite level, let widehat C_A be a finite family of matrix constraints, with fixed scalar structure coefficients, and let Π^phys be the orthogonal projector onto their exact common kernel. If the classical constraint algebra has structure coefficients f_AB^ C, define the anomaly operator A_AB = [widehat C_A,widehat C_B] -i∑_C f_AB^ Cwidehat C_C. Its physical packet is Π^phys A_ABΠ^phys. In this exact finite setting, widehat C_CΠ^phys=0 for every C. Associativity gives A_ABΠ^phys=0, Π^phys…

    Exact mathematical passage
    
    \boxed{
    \mathfrak A_{AB}
    =
    [\widehat C_A,\widehat C_B]
    -i\sum_C f_{AB}^{\ \ C}\widehat C_C.
    }
    
\widetilde BUse in source · 9 passages

Search aliases: widetilde B widetilde

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  • Use in source · monograph_atlas.tex, line 660

    In its elimination domain, Σ(z)=1/(z-2). At z=3+ i, Σ(3+ i)=frac1- i2, ImΣ(z)=-(Im z)|(z-2)^-1|^2≤0. The sign in the upper half plane comes from self-adjoint hidden data. It is not an entrywise sign condition on an arbitrary effective matrix. xfigstability headA stability estimate with a common spectral gap Compare (B,D)=(1,2) with (widetilde B,widetilde D)=(9/8,17/8) at z=3. Both hidden spectral distances are at least δ=3/4, and both couplings are bounded by g=9/8. Then |Σ-widetildeΣ|=|1-frac81…

    Exact mathematical passage
    (\widetilde B,\widetilde D)=(9/8,17/8)
\widetilde B^*Use in source · 2 passages

Search aliases: widetilde B^* widetilde

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  • Use in source · Read passage · 02_strengthened.tex, line 1787

    [Stability of the self energy] Let D=D^* and widetilde D=widetilde D^* act on one fixed hidden Hilbert space, and let B,widetilde B map that hidden space to one fixed retained Hilbert space. Define Σ(z)=B(z-D)^-1B^*, widetildeΣ(z)=widetilde B(z-widetilde D)^-1widetilde B^*. Assume norm B,normwidetilde B≤ g and dist(z,Spec D), dist(z,Specwidetilde D) ≥δ>0. Then normΣ(z)-widetildeΣ(z) ≤ frac2gδnormB-widetilde B + fracg^2δ^2normD-widetilde D.

    Exact mathematical passage
    
    \Sigma(z)=B(z-D)^{-1}B^*,
    \qquad
    \widetilde\Sigma(z)=\widetilde B(z-\widetilde D)^{-1}\widetilde B^*.
    
\widetilde CUse in source · 5 passages

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  • Use in source · monograph_atlas.tex, line 753

    ull algebra closes: [C_x,C_y]=2 i C_z, [C_y,C_z]=2 i C_x, [C_z,C_x]=2 i C_y. These are uncompressed identities. They supply an actual closure test in the quotient by the constraint span, unlike the automatic compressed zero on the physical kernel. xfigconstraint_image headExact transport holds on the coarse image Embed by the coordinate isometry R: C^3→ C^4 and set widetilde C_a=C_a⊕1. Then widetilde C_aR=RC_a, so [widetilde C_a,widetilde C_b]R=R[C_a,C_b]. The coarse physical vector maps into th…

    Exact mathematical passage
    \widetilde C_a=C_a\oplus1
\widetilde C_aUse in source · 3 passages

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  • Use in source · monograph_atlas.tex, line 753

    ull algebra closes: [C_x,C_y]=2 i C_z, [C_y,C_z]=2 i C_x, [C_z,C_x]=2 i C_y. These are uncompressed identities. They supply an actual closure test in the quotient by the constraint span, unlike the automatic compressed zero on the physical kernel. xfigconstraint_image headExact transport holds on the coarse image Embed by the coordinate isometry R: C^3→ C^4 and set widetilde C_a=C_a⊕1. Then widetilde C_aR=RC_a, so [widetilde C_a,widetilde C_b]R=R[C_a,C_b]. The coarse physical vector maps into th…

    Exact mathematical passage
    \widetilde C_a=C_a\oplus1
\widetilde C_bUse in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 754

    C_x, [C_z,C_x]=2 i C_y. These are uncompressed identities. They supply an actual closure test in the quotient by the constraint span, unlike the automatic compressed zero on the physical kernel. xfigconstraint_image headExact transport holds on the coarse image Embed by the coordinate isometry R: C^3→ C^4 and set widetilde C_a=C_a⊕1. Then widetilde C_aR=RC_a, so [widetilde C_a,widetilde C_b]R=R[C_a,C_b]. The coarse physical vector maps into the fine common kernel. However, the same prescribed Pa…

    Exact mathematical passage
    
    [\widetilde C_a,\widetilde C_b]R=R[C_a,C_b].
    
\widetilde C_xUse in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 759

    e coarse physical vector maps into the fine common kernel. However, the same prescribed Pauli structure does not close on the whole fine level: on the added coordinate the commutator is zero, whereas 2 iwidetilde C_z is 2 i. Exact transport constrains the image of R and leaves its orthogonal complement as separate data. headAn approximate residual is also explicit Perturb only widetilde C_x by (1/10)ket0bra0. For the unit coarse physical vector, the fine constraint residual is exactly 1/10. The …

    Exact mathematical passage
    \widetilde C_x
\widetilde C_zUse in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 757

    the coarse image Embed by the coordinate isometry R: C^3→ C^4 and set widetilde C_a=C_a⊕1. Then widetilde C_aR=RC_a, so [widetilde C_a,widetilde C_b]R=R[C_a,C_b]. The coarse physical vector maps into the fine common kernel. However, the same prescribed Pauli structure does not close on the whole fine level: on the added coordinate the commutator is zero, whereas 2 iwidetilde C_z is 2 i. Exact transport constrains the image of R and leaves its orthogonal complement as separate data. headAn approx…

    Exact mathematical passage
    2\ii\widetilde C_z
\widetilde DUse in source · 8 passages

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  • Use in source · monograph_atlas.tex, line 660

    In its elimination domain, Σ(z)=1/(z-2). At z=3+ i, Σ(3+ i)=frac1- i2, ImΣ(z)=-(Im z)|(z-2)^-1|^2≤0. The sign in the upper half plane comes from self-adjoint hidden data. It is not an entrywise sign condition on an arbitrary effective matrix. xfigstability headA stability estimate with a common spectral gap Compare (B,D)=(1,2) with (widetilde B,widetilde D)=(9/8,17/8) at z=3. Both hidden spectral distances are at least δ=3/4, and both couplings are bounded by g=9/8. Then |Σ-widetildeΣ|=|1-frac81…

    Exact mathematical passage
    (\widetilde B,\widetilde D)=(9/8,17/8)
\widetilde D^*Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 1786

    [Stability of the self energy] Let D=D^* and widetilde D=widetilde D^* act on one fixed hidden Hilbert space, and let B,widetilde B map that hidden space to one fixed retained Hilbert space. Define Σ(z)=B(z-D)^-1B^*, widetildeΣ(z)=widetilde B(z-widetilde D)^-1widetilde B^*. Assume norm B,normwidetilde B≤ g and dist(z,Spec D), dist(z,Specwidetilde D) ≥δ>0. Then normΣ(z)-widetildeΣ(z) ≤ frac2gδnormB-widetilde B + fracg^2δ^2normD-widetilde D.

    Exact mathematical passage
    \widetilde D=\widetilde D^*
\widetilde\SigmaUse in source · 4 passages

Search aliases: widetildeΣ widetilde Sigma

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  • Use in source · monograph_atlas.tex, line 661

    The sign in the upper half plane comes from self-adjoint hidden data. It is not an entrywise sign condition on an arbitrary effective matrix. xfigstability headA stability estimate with a common spectral gap Compare (B,D)=(1,2) with (widetilde B,widetilde D)=(9/8,17/8) at z=3. Both hidden spectral distances are at least δ=3/4, and both couplings are bounded by g=9/8. Then |Σ-widetildeΣ|=|1-frac8156|=frac2556, frac2gδ|B-widetilde B| +fracg^2δ^2|D-widetilde D|=frac2132. The theorem bounds the diff…

    Exact mathematical passage
    
    |\Sigma-\widetilde\Sigma|=\left|1-\frac{81}{56}\right|=\frac{25}{56},
    \qquad
    \frac{2g}{\delta}|B-\widetilde B|
    +\frac{g^2}{\delta^2}|D-\widetilde D|=\frac{21}{32}.
    
X^*Use in source · 4 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 939

    Density matrices and observables carry both an input packet and an output packet. Equip End( H) with the Hilbert Schmidt inner product ipXY_HS=Tr(X^*Y).

    Exact mathematical passage
    
    \ip{X}{Y}_{\HS}=\Tr(X^*Y).
    
x^*Use in source · 1 passage

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  • Use in source · Read passage · 03_supplement_05.tex, line 135

    Complex polarization reaches the whole operator space. Write q(x)=xx^*. The module proves the exact identity 4xy^*=q(x+y)-q(x-y) +i(q(x+iy)-q(x-iy)). Agreement on all positive pure outer products therefore implies agreement on every outer product. Actual matrix units then span the full matrix space. Applying this argument to the sandwich by P proves equality on every code-supported operator, including non-Hermitian ones.

    Exact mathematical passage
    q(x)=xx^*
X^{-1}Use in source · 1 passage

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x^2Use in source · 7 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 1155

    Put x=kh/2. The inequalities |sin x|≤|x| and |x-sin x|≤ |x|^3/6, which hold for every real argument, give 0≤ x^2-sin^2x =|x-sin x| |x+sin x| ≤frac|x|^36 2|x| =fracx^43. Multiplying by 4/h^2 proves both bounds. The estimate holds for every frequency. Its interpretation as convergence of second order keeps k fixed while h→0, so it does not assert a uniformly small relative error across all grid modes.

    Exact mathematical passage
    
    0\le x^2-\sin^2x
    =|x-\sin x|\,|x+\sin x|
    \le\frac{|x|^3}{6}\,2|x|
    =\frac{x^4}{3}.
    
x^3Use in source · 3 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 2049

    For x∈[0,π/2], sin x≤ x and sin x≥ x-fracx^36. Thus 0≤ x^2-sin^2x≤fracx^43. Apply this with x=πabsk_j/N, multiply by 4N^2, and sum over j.

    Exact mathematical passage
    
    \sin x\geq x-\frac{x^3}{6}.
    
x^4Use in source · 7 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 1155

    Put x=kh/2. The inequalities |sin x|≤|x| and |x-sin x|≤ |x|^3/6, which hold for every real argument, give 0≤ x^2-sin^2x =|x-sin x| |x+sin x| ≤frac|x|^36 2|x| =fracx^43. Multiplying by 4/h^2 proves both bounds. The estimate holds for every frequency. Its interpretation as convergence of second order keeps k fixed while h→0, so it does not assert a uniformly small relative error across all grid modes.

    Exact mathematical passage
    
    0\le x^2-\sin^2x
    =|x-\sin x|\,|x+\sin x|
    \le\frac{|x|^3}{6}\,2|x|
    =\frac{x^4}{3}.
    
X_{(i,\cdot),(j,\cdot)}Use in source · 1 passage

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  • Use in source · Read passage · 03_supplement_02.tex, line 206

    To prove complete positivity rather than positivity alone, let J be an arbitrary finite auxiliary index set. For a matrix X indexed by J× n, define its blockwise amplification by [Φ^(J)(X)]_(i,u),(j,v) =Φ(X_(i,·),(j,·))_u,v. The explicit index calculation proves the identity Φ^(J)(X)=∑_a (I_J⊗ K_a)X(I_J⊗ K_a)^*. The displayed identity identifies the defined amplification with tensoring by the identity, which is the operation needed for complete positivity. Every summand on the right is positive …

    Exact mathematical passage
    
     [\Phi^{(J)}(X)]_{(i,u),(j,v)}
     =\Phi\bigl(X_{(i,\cdot),(j,\cdot)}\bigr)_{u,v}.
    
X_1Use in source · 6 passages

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  • Use in source · monograph_atlas.tex, line 38

    bottomrule headNormalization and indexing The tensor factors are ordered from left to right, so X_1=X⊗ I⊗ I. A normalized pure state gives ρ=ψψ^*. A coefficient matrix used to count a seed orbit need not be normalized. Scaling a nonzero seed does not change its generated linear span.

    Exact mathematical passage
    X_1=X\otimes I\otimes I
X_2Use in source · 5 passages

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  • Use in source · monograph_atlas.tex, line 44

    vpage3One seed, eight addressesCYCLICITY DEPENDS ON THE GRAMMARTraditional edition: Proposition II.2.5. Start with ψ_0=ket000 and allow the three bit flip operators X_1,X_2,X_3. For a binary address a=(a_1,a_2,a_3), put W_a=X_1^a_1X_2^a_2X_3^a_3. W_aψ_0=keta_1a_2a_3. The drawing shows the actual eight states reached by these words. Dashed edges connect the two squares by changing the first bit. The other edges change one of the remaining bits. vfigaddresses headTwo different meanings of ``reach'…

    Exact mathematical passage
    X_1,X_2,X_3
X_2^{a_2}Use in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 45

    vpage3One seed, eight addressesCYCLICITY DEPENDS ON THE GRAMMARTraditional edition: Proposition II.2.5. Start with ψ_0=ket000 and allow the three bit flip operators X_1,X_2,X_3. For a binary address a=(a_1,a_2,a_3), put W_a=X_1^a_1X_2^a_2X_3^a_3. W_aψ_0=keta_1a_2a_3. The drawing shows the actual eight states reached by these words. Dashed edges connect the two squares by changing the first bit. The other edges change one of the remaining bits. vfigaddresses headTwo different meanings of ``reach'…

    Exact mathematical passage
    
    W_a=X_1^{a_1}X_2^{a_2}X_3^{a_3}.
    \qquad W_a\psi_0=\ket{a_1a_2a_3}.
    
X_3Use in source · 5 passages

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  • Use in source · monograph_atlas.tex, line 44

    vpage3One seed, eight addressesCYCLICITY DEPENDS ON THE GRAMMARTraditional edition: Proposition II.2.5. Start with ψ_0=ket000 and allow the three bit flip operators X_1,X_2,X_3. For a binary address a=(a_1,a_2,a_3), put W_a=X_1^a_1X_2^a_2X_3^a_3. W_aψ_0=keta_1a_2a_3. The drawing shows the actual eight states reached by these words. Dashed edges connect the two squares by changing the first bit. The other edges change one of the remaining bits. vfigaddresses headTwo different meanings of ``reach'…

    Exact mathematical passage
    X_1,X_2,X_3
X_3^{a_3}Use in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 45

    vpage3One seed, eight addressesCYCLICITY DEPENDS ON THE GRAMMARTraditional edition: Proposition II.2.5. Start with ψ_0=ket000 and allow the three bit flip operators X_1,X_2,X_3. For a binary address a=(a_1,a_2,a_3), put W_a=X_1^a_1X_2^a_2X_3^a_3. W_aψ_0=keta_1a_2a_3. The drawing shows the actual eight states reached by these words. Dashed edges connect the two squares by changing the first bit. The other edges change one of the remaining bits. vfigaddresses headTwo different meanings of ``reach'…

    Exact mathematical passage
    
    W_a=X_1^{a_1}X_2^{a_2}X_3^{a_3}.
    \qquad W_a\psi_0=\ket{a_1a_2a_3}.
    
x_iUse in source · 1 passage

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  • Use in source · Read passage · 03_supplement_02.tex, line 48

    Let F be an arbitrary finite set of factors and let D_i be a finite coordinate index for factor i. For matrix families A_i, define the coordinate tensor product on the product index space by T(A)(x,y)=∏_i∈ F A_i(x_i,y_i). The proof first establishes the laws for multiplication, identity, adjoints, and finite sums. These laws apply to any finite number of factors with the stated finite coordinate sets.

    Exact mathematical passage
    
     \mathsf T(A)(x,y)=\prod_{i\in F} A_i(x_i,y_i).
    
X_j^{a_j}Use in source · 1 passage

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  • Use in source · Read passage · 03_supplement_02.tex, line 21

    For every binary address a, W_a=∏_j=0^n-1X_j^a_j=T_a, W_aψ_0=ket a. The family (W_aψ_0)_a∈ A_n is linearly independent, spans V_n, and has exactly 2^n elements. It is the standard computational basis.

    Exact mathematical passage
    
     W_a=\prod_{j=0}^{n-1}X_j^{a_j}=T_a,
     \qquad W_a\psi_0=\ket a.
    
\xmapstoUse in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 126

    vpage8Track the Bell state through the circuitINTERMEDIATE PACKETS ARE NOT FINAL PACKETSTraditional edition: Theorem II.4.1, Example II.4.6. The input is ket00. First apply a Hadamard to the first qubit, then a controlled flip: ket00 xmapstoH_rm Had⊗ I fracket00+ket10sqrt2 xmapstorm CNOT fracket00+ket11sqrt2. The displayed columns keep amplitudes, including their normalization, at every step. The middle vector occupies both parity packets. The final vector occupies only the even packet. vfigbell…

    Exact mathematical passage
    
    \ket{00}\ \xmapsto{H_{\rm Had}\otimes I}\
    \frac{\ket{00}+\ket{10}}{\sqrt2}
    \ \xmapsto{\rm CNOT}\
    \frac{\ket{00}+\ket{11}}{\sqrt2}.
    
yUse in source · 40 passages

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  • Use in source · monograph_atlas.tex, line 210

    vpage12A moving frame creates a connection termNOT ALL MOTION IS PHYSICAL EVOLUTIONTraditional edition: Theorem II.6.3. Set the laboratory Hamiltonian to zero and keep ψ(t)=ket0 fixed. Describe it in rotating coordinates, U(t)=matcos t · -sin t sin t · cos t, y(t)=U(t)^*ψ(t)=matcos t -sin t. The vector has not moved in the laboratory, but its coordinate entries have changed. vfigmoving_frame headThe missing term can be computed exactly Let J=mat0 · -1

    Exact mathematical passage
    
    U(t)=\mat{\cos t&-\sin t\\\sin t&\cos t},
    \qquad y(t)=U(t)^*\psi(t)=\mat{\cos t\\-\sin t}.
    
y^*Use in source · 1 passage

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  • Use in source · Read passage · 03_supplement_05.tex, line 136

    Complex polarization reaches the whole operator space. Write q(x)=xx^*. The module proves the exact identity 4xy^*=q(x+y)-q(x-y) +i(q(x+iy)-q(x-iy)). Agreement on all positive pure outer products therefore implies agreement on every outer product. Actual matrix units then span the full matrix space. Applying this argument to the sandwich by P proves equality on every code-supported operator, including non-Hermitian ones.

    Exact mathematical passage
    
    4xy^*=q(x+y)-q(x-y)
    +i\bigl(q(x+iy)-q(x-iy)\bigr).
    
Y^{-1}Use in source · 1 passage

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y_iUse in source · 1 passage

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  • Use in source · Read passage · 03_supplement_02.tex, line 48

    Let F be an arbitrary finite set of factors and let D_i be a finite coordinate index for factor i. For matrix families A_i, define the coordinate tensor product on the product index space by T(A)(x,y)=∏_i∈ F A_i(x_i,y_i). The proof first establishes the laws for multiplication, identity, adjoints, and finite sums. These laws apply to any finite number of factors with the stated finite coordinate sets.

    Exact mathematical passage
    
     \mathsf T(A)(x,y)=\prod_{i\in F} A_i(x_i,y_i).
    
\mathbb ZUse in source · 5 passages

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  • Use in source · Read passage · 03_supplement_02.tex, line 5

    For n≥ 0, let A_n=( Z/2 Z)^{0,…,n-1}, V_n={v:A_n→ C}. For an address a∈ A_n, define the standard coordinate vector ket a(x)=1 · x=a,

    Exact mathematical passage
    
     A_n=(\mathbb Z/2\mathbb Z)^{\{0,\ldots,n-1\}},\qquad
     V_n=\{v:A_n\to\C\}.
    
Z^*Use in source · 2 passages

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  • Use in source · Read passage · 03_supplement_05.tex, line 111

    Trace-preserving recovery supplies the original Gram data. Let Z_ra=z_ra. The recovery normalization gives PE_a^*E_bP · =PE_a^*(∑_rR_r^*R_r)E_bP · =∑_r(R_rE_aP)^*(R_rE_bP) · =(∑_roverlinez_raz_rb)P =(Z^*Z)_abP. Thus C=Z^*Z is positive semidefinite and satisfies the required compressed identities. The theorem pathgram_of_recovery implements this calculation with the original error and recovery matrices.

    Exact mathematical passage
    
    PE_a^*E_bP
    &=PE_a^*\Bigl(\sum_rR_r^*R_r\Bigr)E_bP\\
    &=\sum_r(R_rE_aP)^*(R_rE_bP)\\
    &=\Bigl(\sum_r\overline{z_{ra}}z_{rb}\Bigr)P
    =(Z^*Z)_{ab}P.
    
z^*Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 1339

    For z∈ C^r, let F_z=∑_az_aE_a. Then PF_z^*F_zP=(z^*cz)P≥0, so c≥0. The unitary change of error coordinates gives PF_j^*F_ℓ P = λ_jδ_jℓP. Thus V_j^*V_ℓ=δ_jℓP. Each V_j is an isometry on P H, and distinct ranges are orthogonal. Their range projectors are therefore pairwise orthogonal.

    Exact mathematical passage
    
    PF_z^*F_zP=(z^*cz)P\geq0,
    
z^2Use in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 382

    1 · 2 and retain its first coordinate. The eliminated block is H_QQ=2. Whenever z-2 and the full zI-H are invertible, H_rm eff(z)=frac1z-2, [(zI-H)^-1]_00 =frac1z-1/(z-2)=fracz-2z^2-2z-1. This is the corrected hypothesis set recorded in the formal release. vfigfeshbach At z=3, the exact retained resolvent is 1/2. Bare truncation uses only H_PP=0 and gives 1/3, an error of 1/6. The omitted coupling has changed the response even though the retained diagonal entry did not change. headA pole can bel…

    Exact mathematical passage
    
    H_{\rm eff}(z)=\frac1{z-2},\qquad
    \bigl[(zI-H)^{-1}\bigr]_{00}
    =\frac1{z-1/(z-2)}=\frac{z-2}{z^2-2z-1}.
    
z^nUse in source · 3 passages

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  • Use in source · monograph_atlas.tex, line 670

    |=frac2556, frac2gδ|B-widetilde B| +fracg^2δ^2|D-widetilde D|=frac2132. The theorem bounds the difference using a common spectral gap. Applying the bound uniformly to a refinement family requires uniform spectral separation and control of the couplings. headA series near zero energy and its exact remainder At z=1/2, |z| |D^-1|=1/4<1, so Σ(z)=-∑_n=0^∞fracz^n2^n+1. After the first four terms, the exact remainder has magnitude 1/384. The geometric series controls the infinite tail. The retained che…

    Exact mathematical passage
    
    \Sigma(z)=-\sum_{n=0}^{\infty}\frac{z^n}{2^{n+1}}.
    
Z^{\otimes n}Use in source · 1 passage

Search aliases: Z^⊗ n otimes

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  • Use in source · Read passage · 01_finite_core.tex, line 228

    For parity, S=Z^⊗ n, P_even=fracI+S2, P_odd=fracI-S2.

    Exact mathematical passage
    
    S=Z^{\otimes n},
    \qquad
    P_{\mathrm{even}}=\frac{I+S}{2},
    \qquad
    P_{\mathrm{odd}}=\frac{I-S}{2}.
    
Z^{\otimes3}Use in source · 1 passage

Search aliases: Z^⊗3 otimes

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  • Use in source · Read passage · 01_finite_core.tex, line 270

    [Exact parity refinement] For three qubits, the local computational projectors were grouped by the parity of their Hamming weight. The resulting coarse projectors agreed with (I± Z^⊗3)/2 with residual 0.

    Exact mathematical passage
    (I\pm Z^{\otimes3})/2
Z_1Use in source · 6 passages

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  • Use in source · monograph_atlas.tex, line 361

    vpage20An unchanged syndrome can hide a logical errorTHE SCALAR COMPRESSION TEST MATTERSTraditional edition: Theorem II.8.2, Proposition II.8.7. Apply Z_1=Z⊗ I⊗ I to the same repetition code. It sends ket000 to itself and ket111 to its negative. Both states remain inside the original code, so the previous syndrome partition reports no bit flip. frac3ket000+4ket1115 ⟼ frac3ket000-4ket1115. The populations are unchanged, but the relative phase is not. vfiglogical_error Let V be the code isometry w…

    Exact mathematical passage
    Z_1=Z\otimes I\otimes I
z_aUse in source · 3 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 1338

    For z∈ C^r, let F_z=∑_az_aE_a. Then PF_z^*F_zP=(z^*cz)P≥0, so c≥0. The unitary change of error coordinates gives PF_j^*F_ℓ P = λ_jδ_jℓP. Thus V_j^*V_ℓ=δ_jℓP. Each V_j is an isometry on P H, and distinct ranges are orthogonal. Their range projectors are therefore pairwise orthogonal.

    Exact mathematical passage
    F_z=\sum_az_aE_a
Z_dUse in source · 3 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 2107

    [Theta transformation] The continuum flat torus heat trace satisfies Z_d(t) = ∑_k∈ Z^d e^-4π^2tabsk^2 = (4π t)^-d/2 ∑_n∈ Z^d e^-absn^2/(4t). This is the Poisson summation formula for a Gaussian.

    Exact mathematical passage
    
    Z_d(t)
    =
    \sum_{k\in\ZZ^d}\e^{-4\pi^2t\abs{k}^2}
    =
    (4\pi t)^{-d/2}
    \sum_{n\in\ZZ^d}\e^{-\abs{n}^2/(4t)}.
    
Z_{L,a}Use in source · 3 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 1993

    [Heat packet decomposition] If [L,P_a]=0 for every packet, then Z_L(t)=∑_aZ_L,a(t), Z_L,a(t)=Tr(P_a e^-tL). The global spectral dimension is the average of the packet dimensions weighted by their heat traces: d_L(t) = ∑_a:Z_L,a(t)>0 fracZ_L,a(t)Z_L(t) d_L,a(t), where d_L,a(t) =2t fracTr(P_aL e^-tL)Z_L,a(t) for nonempty packet heat traces.

    Exact mathematical passage
    
    Z_L(t)=\sum_aZ_{L,a}(t),
    \qquad
    Z_{L,a}(t)=\Tr(P_a\e^{-tL}).
    
Z_NUse in source · 4 passages

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  • Use in source · monograph_atlas.tex, line 725

    vpage37The dimension window has an order of limitsFINITE HEAT DATA AND THE QUANTIFIERSTraditional edition: Theorem II.11.5, Corollary II.11.8. For the unit circle grid with N sites, the scaled eigenvalues are λ_N(k)=4N^2sin^2(π k/N). Put Z_N(t)=∑_ke^-tλ_N(k) and d_N(t)=2t∑_kλ_N(k)e^-tλ_N(k)/Z_N(t).

    Exact mathematical passage
    Z_N(t)=\sum_ke^{-t\lambda_N(k)}
Z_{ra}Use in source · 1 passage

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  • Use in source · Read passage · 03_supplement_05.tex, line 110

    Trace-preserving recovery supplies the original Gram data. Let Z_ra=z_ra. The recovery normalization gives PE_a^*E_bP · =PE_a^*(∑_rR_r^*R_r)E_bP

    Exact mathematical passage
    Z_{ra}=z_{ra}
z_{ra}Use in source · 3 passages

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  • Use in source · Read passage · 03_supplement_05.tex, line 103

    Applied to the corrected Kraus family, this yields scalars z_ra with R_rE_aP=z_raP. The essential declarations are pathrank_one_gram_rigidity, pathkraus_rank_one_rigidity and pathcorrected_kraus_family. No rank-one Choi characterization is inserted as an axiom or as the desired conclusion in hypothesis form.

    Exact mathematical passage
    z_{ra}
z_{rb}Use in source · 1 passage

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  • Use in source · Read passage · 03_supplement_05.tex, line 111

    Trace-preserving recovery supplies the original Gram data. Let Z_ra=z_ra. The recovery normalization gives PE_a^*E_bP · =PE_a^*(∑_rR_r^*R_r)E_bP · =∑_r(R_rE_aP)^*(R_rE_bP) · =(∑_roverlinez_raz_rb)P =(Z^*Z)_abP. Thus C=Z^*Z is positive semidefinite and satisfies the required compressed identities. The theorem pathgram_of_recovery implements this calculation with the original error and recovery matrices.

    Exact mathematical passage
    
    PE_a^*E_bP
    &=PE_a^*\Bigl(\sum_rR_r^*R_r\Bigr)E_bP\\
    &=\sum_r(R_rE_aP)^*(R_rE_bP)\\
    &=\Bigl(\sum_r\overline{z_{ra}}z_{rb}\Bigr)P
    =(Z^*Z)_{ab}P.
    
\ZZ^dUse in source · 4 passages

Search aliases: ZZ^d Z^d ZZ mathbb

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  • Use in source · Read passage · 02_strengthened.tex, line 2061

    [Fixed time heat trace convergence] For every t>0, ∑_k∈Λ_N^* e^-tλ_N(k) ⟶ ∑_k∈ Z^d e^-4π^2tabsk^2 as N→∞. The first spectral moments also converge: ∑_k∈Λ_N^* λ_N(k) e^-tλ_N(k) ⟶ ∑_k∈ Z^d 4π^2absk^2 e^-4π^2tabsk^2. Consequently, the discrete spectral dimensions converge to the continuum torus spectral dimension at every fixed positive time.

    Exact mathematical passage
    
    \sum_{k\in\Lambda_N^*}
    \e^{-t\lambda_N(k)}
    \longrightarrow
    \sum_{k\in\ZZ^d}
    \e^{-4\pi^2t\abs{k}^2}
    
|^2Use in source · 3 passages

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  • Use in source · monograph_atlas.tex, line 156

    ity. Starting from ket0, there are two resolved paths to output ket1. Their signed products are bra1H_rm Hadket0bra0H_rm Hadket0=frac12, bra1H_rm Hadket1bra1H_rm Hadket0=-frac12. Their sum is zero. Squaring each separately gives a different answer. vfiginterference headWhere the missing term goes For path amplitudes a,b, the outcome probability is |a+b|^2=|a|^2+|b|^2+2Re(abar b). Here the last term is -1/2, canceling the first two terms. The path picture retains this information only if its edge…

    Exact mathematical passage
    |a+b|^2=|a|^2+|b|^2+2\Re(a\bar b)
|^3Use in source · 3 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 1154

    Put x=kh/2. The inequalities |sin x|≤|x| and |x-sin x|≤ |x|^3/6, which hold for every real argument, give 0≤ x^2-sin^2x =|x-sin x| |x+sin x| ≤frac|x|^36 2|x| =fracx^43. Multiplying by 4/h^2 proves both bounds. The estimate holds for every frequency. Its interpretation as convergence of second order keeps k fixed while h→0, so it does not assert a uniformly small relative error across all grid modes.

    Exact mathematical passage
    |x-\sin x|\le |x|^3/6
|_{U_a}Use in source · 1 passage

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  • Use in source · Read passage · 03_supplement_06.tex, line 43

    ). For x∈ U_a, B_a(x): E_a⟶ E_x, v⟼ T_a(x)v, A_a(x): E_x⟶ E_a, w⟼ P(a)T_a(x)^-1w. The intertwining identity and its inverse counterpart show that the displayed targets are correct. Lean proves both inverse laws, continuity, linearity in the fiber and smooth dependence on the base. Thus E|_U_a ≅ U_a× E_a is a local product homeomorphism that preserves the base point.

    Exact mathematical passage
    
    \mathcal E|_{U_a}\ \cong\ U_a\times\mathcal E_a
    
\pmUse in source · 7 passages

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  • Use in source · monograph_atlas.tex, line 179

    1 · 0. The even block squares to (25/16)I, so its eigenvalues are ±5/4. The odd block squares to I, so its eigenvalues are ±1. Exponentiating either block gives the corresponding part of the exact evolution. Transfer between the packets remains zero for every real time. headWhat has changed? Only the order of basis vectors has changed. No matrix entries, amplitudes, or energy levels were discarded. This is why the decomposition is exact. Keeping just the even block would be a separate restrictio…

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    \pm5/4
\cdotUse in source · 11 passages

Search aliases: · cdot

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  • Use in source · monograph_atlas.tex, line 273

    vpage15Curvature measures a local area responseAN EXACT BLOCH PROJECTOR CALCULATIONTraditional edition: Theorem II.6.7, Corollary II.6.8. On the unit sphere, set n=(sinθcosϕ,sinθsinϕ,cosθ) and P(θ,ϕ)=frac12(I+n·σ). This is a smooth rank-one orthogonal projector. The intrinsic curvature is the endomorphism-valued two-form P( d Pwedge d P)P. With the paper's scalar convention, its component is F_θϕ=- iTr (P[∂_θ P,∂_ϕ P]) =frac12sinθ. vfigbloch_curvature headA local frame gives the same answer Away…

    Exact mathematical passage
    
    P(\theta,\phi)=\frac12(I+n\cdot\sigma).
    
\timesUse in source · 29 passages

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  • Use in source · monograph_atlas.tex, line 56

    The exact check constructs each 8×8 word matrix, applies it to the seed, and verifies that the matrix of all eight outputs is the identity. It also tests the displayed superposition against every word output. No search over an unspecified gate set is involved. takeawayA cyclic seed generates a vector space under an algebra. That conclusion does not automatically provide a unitary preparation procedure for every vector in it.

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    8\times8
\alpha_0Use in source · 2 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 282

    [Exact circuit path expansion] For source packet α_0 and target packet α_m, P_α_mUP_α_0 = ∑_α_1,…,α_m-1 P_α_mU_mP_α_m-1 ⋯ P_α_1U_1P_α_0. Summing over the source and target packets reconstructs the complete circuit operator.

    Exact mathematical passage
    \alpha_0
\alpha_1Use in source · 1 passage

Search aliases: α_1 alpha

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  • Use in source · Read passage · 01_finite_core.tex, line 283

    [Exact circuit path expansion] For source packet α_0 and target packet α_m, P_α_mUP_α_0 = ∑_α_1,…,α_m-1 P_α_mU_mP_α_m-1 ⋯ P_α_1U_1P_α_0. Summing over the source and target packets reconstructs the complete circuit operator.

    Exact mathematical passage
    
    \boxed{
    P_{\alpha_m}UP_{\alpha_0}
    =
    \sum_{\alpha_1,\ldots,\alpha_{m-1}}
    P_{\alpha_m}U_mP_{\alpha_{m-1}}
    \cdots
    P_{\alpha_1}U_1P_{\alpha_0}.
    }
    
\alpha_mUse in source · 2 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 282

    [Exact circuit path expansion] For source packet α_0 and target packet α_m, P_α_mUP_α_0 = ∑_α_1,…,α_m-1 P_α_mU_mP_α_m-1 ⋯ P_α_1U_1P_α_0. Summing over the source and target packets reconstructs the complete circuit operator.

    Exact mathematical passage
    \alpha_m
\alpha_{m-1}Use in source · 1 passage

Search aliases: α_m-1 alpha

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  • Use in source · Read passage · 01_finite_core.tex, line 283

    [Exact circuit path expansion] For source packet α_0 and target packet α_m, P_α_mUP_α_0 = ∑_α_1,…,α_m-1 P_α_mU_mP_α_m-1 ⋯ P_α_1U_1P_α_0. Summing over the source and target packets reconstructs the complete circuit operator.

    Exact mathematical passage
    
    \boxed{
    P_{\alpha_m}UP_{\alpha_0}
    =
    \sum_{\alpha_1,\ldots,\alpha_{m-1}}
    P_{\alpha_m}U_mP_{\alpha_{m-1}}
    \cdots
    P_{\alpha_1}U_1P_{\alpha_0}.
    }
    
\gammaUse in source · 19 passages

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  • Use in source · monograph_atlas.tex, line 311

    vpage17A channel acts on four matrix entriesPOPULATIONS AND COHERENCES TRANSFORM DIFFERENTLYTraditional edition: Theorem II.7.6, Example II.7.12. Choose amplitude damping with γ=9/25: K_0=mat1 · 0

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    \gamma=9/25
\gamma'Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 457

    [Path interference formula] Fix a source vector ψ∈ P_a_0 H and a target packet b. Let Γ_b be the set of packet paths from a_0 to b, and set η_γ=U_γψ. Choose any total order on this finite path set. Then normP_bUψ^2 = ∑_γ∈Γ_bnormη_γ^2 + 2Re ∑_substackγ,γ'∈Γ_b γ<γ' ipη_γη_γ'. Consequently, normP_bUψ ≤ ∑_γ∈Γ_bnormη_γ. If the path outputs are pairwise orthogonal, the target probability is the sum of the path probabilities.

    Exact mathematical passage
    
    \norm{P_bU\psi}^2
    =
    \sum_{\gamma\in\Gamma_b}\norm{\eta_\gamma}^2
    +
    2\operatorname{Re}
    \sum_{\substack{\gamma,\gamma'\in\Gamma_b\\ \gamma<\gamma'}}
    \ip{\eta_\gamma}{\eta_{\gamma'}}.
    
\Gamma_bUse in source · 4 passages

Search aliases: Γ_b Gamma

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  • Use in source · Read passage · 02_strengthened.tex, line 452

    [Path interference formula] Fix a source vector ψ∈ P_a_0 H and a target packet b. Let Γ_b be the set of packet paths from a_0 to b, and set η_γ=U_γψ. Choose any total order on this finite path set. Then normP_bUψ^2 = ∑_γ∈Γ_bnormη_γ^2 + 2Re ∑_substackγ,γ'∈Γ_b

    Exact mathematical passage
    \Gamma_b
\delta^2Use in source · 4 passages

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  • Use in source · monograph_atlas.tex, line 661

    The sign in the upper half plane comes from self-adjoint hidden data. It is not an entrywise sign condition on an arbitrary effective matrix. xfigstability headA stability estimate with a common spectral gap Compare (B,D)=(1,2) with (widetilde B,widetilde D)=(9/8,17/8) at z=3. Both hidden spectral distances are at least δ=3/4, and both couplings are bounded by g=9/8. Then |Σ-widetildeΣ|=|1-frac8156|=frac2556, frac2gδ|B-widetilde B| +fracg^2δ^2|D-widetilde D|=frac2132. The theorem bounds the diff…

    Exact mathematical passage
    
    |\Sigma-\widetilde\Sigma|=\left|1-\frac{81}{56}\right|=\frac{25}{56},
    \qquad
    \frac{2g}{\delta}|B-\widetilde B|
    +\frac{g^2}{\delta^2}|D-\widetilde D|=\frac{21}{32}.
    
\delta_{ab}Use in source · 8 passages

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  • Use in source · monograph_atlas.tex, line 355

    The Knill--Laflamme compressions are PE_a^*E_bP=δ_abP. Their scalar form says that the error labels do not resolve the encoded vector. The exact checks evaluate all sixteen compressions, all sixteen syndrome products, the four probabilities, the recovery normalization, and the full recovered matrix.

    Exact mathematical passage
    PE_a^*E_bP=\delta_{ab}P
\delta_{ac}Use in source · 4 passages

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  • Use in source · monograph_atlas.tex, line 159

    The packetwise unitarity identity is likewise an operator identity, including the off-diagonal cancellations: ∑_b U_ba^*U_bc=δ_acP_a, U_ba=P_bUP_a. It cannot be replaced by the assertion that every path individually has unit norm. The exact checks verify all four choices of a,c for the two rank-one packets, as well as the two path products leading to the opposite output.

    Exact mathematical passage
    
    \sum_b U_{ba}^*U_{bc}=\delta_{ac}P_a,
    \qquad U_{ba}=P_bUP_a.
    
\delta_{ba}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 386

    Let U=U_mU_m-1⋯ U_1 be a finite circuit with m≥1, and let (P_a)_a∈ I be a complete orthogonal packet family. For the empty circuit, U=I and its transfer block is P_bP_a=δ_baP_a, whose endpoint sum reconstructs I.

    Exact mathematical passage
    P_bP_a=\delta_{ba}P_a
\delta_{bd}Use in source · 3 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 424

    [Packet unitarity identities] If U is unitary and U_ba=P_bUP_a, then ∑_bU_ba^*U_bc=δ_acP_a and ∑_aU_baU_da^*=δ_bdP_b.

    Exact mathematical passage
    
    \sum_aU_{ba}U_{da}^*=\delta_{bd}P_b.
    
\delta_{jk}Use in source · 5 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 206

    [Cyclic quantum projectors] The operators P_j = frac1N∑_r=0^N-1ω^-jrS^r, 0≤ j<N, are self-adjoint, pairwise orthogonal projectors satisfying P_jP_k=δ_jkP_j, ∑_j=0^N-1P_j=I, SP_j=ω^jP_j.

    Exact mathematical passage
    
    P_jP_k=\delta_{jk}P_j,
    \qquad
    \sum_{j=0}^{N-1}P_j=I,
    \qquad
    SP_j=\omega^jP_j.
    
\delta_{j\ell}Use in source · 2 passages

Search aliases: δ_jℓ delta ell

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  • Use in source · Read passage · 02_strengthened.tex, line 1343

    For z∈ C^r, let F_z=∑_az_aE_a. Then PF_z^*F_zP=(z^*cz)P≥0, so c≥0. The unitary change of error coordinates gives PF_j^*F_ℓ P = λ_jδ_jℓP. Thus V_j^*V_ℓ=δ_jℓP. Each V_j is an isometry on P H, and distinct ranges are orthogonal. Their range projectors are therefore pairwise orthogonal.

    Exact mathematical passage
    
    PF_j^*F_\ell P
    =
    \lambda_j\delta_{j\ell}P.
    
\delta_{rs}Use in source · 5 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 846

    textitSufficiency. Diagonalize C=Udiag(λ_r)U^* with U unitary and λ_r≥0. Define compressed transformed errors F_r=∑_aU_arE_aP. Then F_rP=F_r and F_r^*F_s=λ_rδ_rsP. If λ_r=0, F_r^*F_r=0 forces F_r=0. For positive eigenvalues only, set V_r=F_r/sqrtλ_r. These satisfy V_rP=V_r, V_r^*V_s=δ_rsP. Let S=∑_λ_r>0V_rV_r^*. Orthogonality makes S an orthogonal projector. Use the recovery branches K_r=V_r^*, K_unused=I-S. They are complete on the whole ambient space because ∑_rK_r^*K_r+K_unused^*K_unused =S+(…

    Exact mathematical passage
    F_r^*F_s=\lambda_r\delta_{rs}P
\delta_{\alpha\gamma}Use in source · 1 passage

Search aliases: δ_αγ delta alpha gamma

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  • Use in source · Read passage · 01_finite_core.tex, line 302

    [Packetwise unitarity conservation] If U is unitary and U_βα=P_β UP_α, then ∑_β U_βα^*U_βγ = δ_αγP_α. Similarly, ∑_α U_βαU_δα^* = δ_βδP_β.

    Exact mathematical passage
    
    \boxed{
    \sum_\beta U_{\beta\alpha}^*U_{\beta\gamma}
    =
    \delta_{\alpha\gamma}P_\alpha.
    }
    
\delta_{\beta\alpha}Use in source · 1 passage

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  • Use in source · Read passage · 01_finite_core.tex, line 279

    Let U=U_mU_m-1⋯ U_1 be a circuit with m≥1, and let {P_α} be a complete packet system. For the empty circuit m=0, set U=I. Its boundary block is P_β P_α=δ_βαP_α.

    Exact mathematical passage
    P_\beta P_\alpha=\delta_{\beta\alpha}P_\alpha
\delta_{\beta\delta}Use in source · 1 passage

Search aliases: δ_βδ delta beta delta

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  • Use in source · Read passage · 01_finite_core.tex, line 310

    [Packetwise unitarity conservation] If U is unitary and U_βα=P_β UP_α, then ∑_β U_βα^*U_βγ = δ_αγP_α. Similarly, ∑_α U_βαU_δα^* = δ_βδP_β.

    Exact mathematical passage
    
    \sum_\alpha U_{\beta\alpha}U_{\delta\alpha}^*
    =
    \delta_{\beta\delta}P_\beta.
    
\delta_{\lambda\mu}Use in source · 2 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 215

    [Finite group isotypic projectors] The operators P_λ = fracd_λabsG ∑_g∈ G overlineχ_λ(g)U(g) are orthogonal projectors. They satisfy P_λ P_μ=δ_λμP_λ, ∑_λ∈widehat GP_λ=I_ H. The range of P_λ is the λ isotypic component of H.

    Exact mathematical passage
    
    P_\lambda P_\mu=\delta_{\lambda\mu}P_\lambda,
    \qquad
    \sum_{\lambda\in\widehat G}P_\lambda=I_{\Hcal}.
    
\Delta_\ellUse in source · 2 passages

Search aliases: Δ_ℓ Delta ell

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  • Use in source · Read passage · 01_finite_core.tex, line 1038

    A coherent refinement should satisfy C_ℓ E_ℓ=I and P_ℓ,α = C_ℓ ( ∑_βsuccαP_ℓ+1,β ) E_ℓ. For an operator D, define the refinement defect Δ_ℓ(D) =C_ℓ D_ℓ+1E_ℓ-D_ℓ. Exact resolution independence is Δ_ℓ(D)=0. When exact equality is too strong, the correct continuum problem is to prove convergence of the resolvents and uniform control of the effective self-energies.

    Exact mathematical passage
    
    \Delta_\ell(D)
    =C_\ell D_{\ell+1}E_\ell-D_\ell.
    
\varepsilon^2Use in source · 2 passages

Search aliases: ε^2 varepsilon

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  • Use in source · monograph_atlas.tex, line 198

    in(ε t)X, normQe^- i tHP=|sin(ε t)|, norm[H,P]=|ε|. The general commutator estimate becomes the elementary bound |sin u|≤ |u|. Unitarity also bounds the amplitude by one. vfigleakage headFrom a norm to a probability For this initial state, the escape probability is sin^2(ε t), not |sin(ε t)|. Consequently Pr(hidden packet at t)≤min{1,ε^2t^2}. At ε t=π/6, the amplitude is 1/2 and the probability is 1/4. Near zero, amplitudes are first order while escape probabilities are second order. Mixing thos…

    Exact mathematical passage
    
    \Pr(\text{hidden packet at }t)\le\min\{1,\varepsilon^2t^2\}.
    
\varepsilon_aUse in source · 3 passages

Search aliases: ε_a varepsilon

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  • Use in source · Read passage · 02_strengthened.tex, line 2296

    [Approximate constraint transport] Assume normC_ℓ+1,aR_ℓ-R_ℓ C_ℓ,a ≤ε_a and normC_ℓ,a,normC_ℓ+1,a≤ M. Then a coarse physical unit vector ψ satisfies normC_ℓ+1,aR_ℓψ≤ε_a. Also, · norm [C_ℓ+1,a,C_ℓ+1,b]R_ℓ -R_ℓ[C_ℓ,a,C_ℓ,b]

    Exact mathematical passage
    
    \norm{C_{\ell+1,a}R_\ell-R_\ell C_{\ell,a}}
    \leq\varepsilon_a
    
\varepsilon_bUse in source · 1 passage

Search aliases: ε_b varepsilon

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  • Use in source · Read passage · 02_strengthened.tex, line 2309

    [Approximate constraint transport] Assume normC_ℓ+1,aR_ℓ-R_ℓ C_ℓ,a ≤ε_a and normC_ℓ,a,normC_ℓ+1,a≤ M. Then a coarse physical unit vector ψ satisfies normC_ℓ+1,aR_ℓψ≤ε_a. Also, · norm [C_ℓ+1,a,C_ℓ+1,b]R_ℓ -R_ℓ[C_ℓ,a,C_ℓ,b] · ≤ 2M(ε_a+ε_b).

    Exact mathematical passage
    
    \begin{aligned}
    &\norm{
    [C_{\ell+1,a},C_{\ell+1,b}]R_\ell
    -R_\ell[C_{\ell,a},C_{\ell,b}]
    }\\
    &\hspace{4em}\leq
    2M(\varepsilon_a+\varepsilon_b).
    \end{aligned}
    
\etaUse in source · 7 passages

Search aliases: η eta

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  • Use in source · monograph_atlas.tex, line 503

    actual amplitude vector is (- i,1, i,1)^T/2, giving uniform site probabilities. The subsequent phases recombine those four amplitudes into a single output at the opposite site. Uniform intermediate probabilities do not imply an incoherent intermediate state. headA channel changes the conclusion predictably Before evolving, mix the seed density matrix with its complete momentum dephasing: ρ_η=(1-η)ket0bra0+η∑_jP_jket0bra0P_j =(1-η)ket0bra0+η I/4, quad0≤η≤1. At transfer time, the probability at th…

    Exact mathematical passage
    
    \rho_\eta=(1-\eta)\ket0\bra0+\eta\sum_jP_j\ket0\bra0P_j
    =(1-\eta)\ket0\bra0+\eta I/4,
    \quad0\le\eta\le1.
    
\eta_\gammaUse in source · 4 passages

Search aliases: η_γ eta gamma

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  • Use in source · Read passage · 02_strengthened.tex, line 453

    [Path interference formula] Fix a source vector ψ∈ P_a_0 H and a target packet b. Let Γ_b be the set of packet paths from a_0 to b, and set η_γ=U_γψ. Choose any total order on this finite path set. Then normP_bUψ^2 = ∑_γ∈Γ_bnormη_γ^2 + 2Re ∑_substackγ,γ'∈Γ_b

    Exact mathematical passage
    
    \eta_\gamma=U_\gamma\psi.
    
\eta_{\gamma'}Use in source · 1 passage

Search aliases: η_γ' eta gamma

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  • Use in source · Read passage · 02_strengthened.tex, line 457

    [Path interference formula] Fix a source vector ψ∈ P_a_0 H and a target packet b. Let Γ_b be the set of packet paths from a_0 to b, and set η_γ=U_γψ. Choose any total order on this finite path set. Then normP_bUψ^2 = ∑_γ∈Γ_bnormη_γ^2 + 2Re ∑_substackγ,γ'∈Γ_b γ<γ' ipη_γη_γ'. Consequently, normP_bUψ ≤ ∑_γ∈Γ_bnormη_γ. If the path outputs are pairwise orthogonal, the target probability is the sum of the path probabilities.

    Exact mathematical passage
    
    \norm{P_bU\psi}^2
    =
    \sum_{\gamma\in\Gamma_b}\norm{\eta_\gamma}^2
    +
    2\operatorname{Re}
    \sum_{\substack{\gamma,\gamma'\in\Gamma_b\\ \gamma<\gamma'}}
    \ip{\eta_\gamma}{\eta_{\gamma'}}.
    
\thetaUse in source · 27 passages

Search aliases: θ theta

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  • Use in source · monograph_atlas.tex, line 272

    vpage15Curvature measures a local area responseAN EXACT BLOCH PROJECTOR CALCULATIONTraditional edition: Theorem II.6.7, Corollary II.6.8. On the unit sphere, set n=(sinθcosϕ,sinθsinϕ,cosθ) and P(θ,ϕ)=frac12(I+n·σ). This is a smooth rank-one orthogonal projector. The intrinsic curvature is the endomorphism-valued two-form P( d Pwedge d P)P. With the paper's scalar convention, its component is F_θϕ=- iTr (P[∂_θ P,∂_ϕ P]) =frac12sinθ. vfigbloch_curvature headA local frame gives the same answer Away…

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    n=(\sin\theta\cos\phi,\sin\theta\sin\phi,\cos\theta)
\theta_0Use in source · 3 passages

Search aliases: θ_0 theta

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  • Use in source · monograph_atlas.tex, line 288

    ∂_ϕ P]) =frac12sinθ. vfigbloch_curvature headA local frame gives the same answer Away from the south pole, use u_N=(cos(θ/2),e^ iϕsin(θ/2))^T. Then P=u_Nu_N^* and the scalar one-form is A_N=- i u_N^* d u_N=frac1-cosθ2 dϕ, d A_N=frac12sinθ dθwedge dϕ. Thus the curvature flux through the cap 0≤θ≤θ_0 is π(1-cosθ_0). At θ_0=π/3, it is exactly π/2. The latitude drawn in the plate illustrates this cap. The exact flux comes from the formula above.

    Exact mathematical passage
    0\le\theta\le\theta_0
\iotaUse in source · 6 passages

Search aliases: ι iota

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  • Use in source · Read passage · 02_strengthened.tex, line 2361

    Let H_∞ be the Hilbert direct limit of the isometric system, and let ι_ℓ: H_ℓ⟶ H_∞ be the canonical isometries.

    Exact mathematical passage
    
    \iota_\ell:\Hcal_\ell\longrightarrow\Hcal_\infty
    
\iota_\ellUse in source · 6 passages

Search aliases: ι_ℓ iota ell

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  • Use in source · Read passage · 02_strengthened.tex, line 2361

    Let H_∞ be the Hilbert direct limit of the isometric system, and let ι_ℓ: H_ℓ⟶ H_∞ be the canonical isometries.

    Exact mathematical passage
    
    \iota_\ell:\Hcal_\ell\longrightarrow\Hcal_\infty
    
\kappaUse in source · 2 passages

Search aliases: κ kappa

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  • Use in source · Read passage · 01_finite_core.tex, line 1079

    The paper tests a controlled volume-state model H_nn=2κ+V(n), H_n,n+1=H_n+1,n=-κ, with κ>0 and a real confining potential. This is a finite transfer-matrix test only. Operator positivity alone is not reflection positivity of a Euclidean field measure. It is not derived from a gravitational path integral and is not evidence for a unique microscopic spacetime dynamics.

    Exact mathematical passage
    
    H_{nn}=2\kappa+V(n),
    \qquad
    H_{n,n+1}=H_{n+1,n}=-\kappa,
    
\lambda^{-1/2}Use in source · 1 passage

Search aliases: λ^-1/2 lambda

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  • Use in source · monograph_atlas.tex, line 610

    0 · 0 · 1, WcW^*=diag(1,0,0), (F_1,F_2,F_3)=(P,0,0). xfiggram headNormalize only positive eigenvalues The positive branch has V_1=P as an isometry on the code, and syndrome support Q=P. No factor λ^-1/2 is formed on either zero branch: those branches vanish on the code. Treating them as extra recoverable packets would divide by zero.

    Exact mathematical passage
    \lambda^{-1/2}
\lambda_jUse in source · 14 passages

Search aliases: λ_j lambda

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  • Use in source · Read passage · 01_finite_core.tex, line 1115

    Let L≥0 be a finite Laplacian on N≥1 states, with eigenvalues λ_j and at least one zero eigenvalue. For diffusion time τ>0, define the normalized heat trace K(τ)=frac1N∑_j e^-τλ_j and the scale-dependent spectral dimension d_s(τ) =-2fracdlog K(τ)dlogτ. For a finite system, d_s(τ) is a diagnostic, not a topological invariant. Indeed, finite differentiation gives d_s(τ)=2τ frac∑_jλ_j e^-τλ_j∑_j e^-τλ_j. It tends to zero as τdownarrow0 and, under the stated assumption of a zero mode, as τ→∞. If a g…

    Exact mathematical passage
    \lambda_j
\lambda_j^{-1/2}Use in source · 1 passage

Search aliases: λ_j^-1/2 lambda

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  • Use in source · Read passage · 02_strengthened.tex, line 1327

    syndrome construction] Assume the Knill Laflamme identities. Then the coefficient matrix c is positive semidefinite. Choose a unitary matrix W such that WcW^*=diag(λ_1,…,λ_r), λ_j≥0, and define F_j=∑_aoverlineW_jaE_a. For every j with λ_j>0, the operator V_j=λ_j^-1/2F_jP is an isometry from the code into H. Its range projector Q_j=V_jV_j^* is a syndrome packet, and the nonzero Q_j are pairwise orthogonal.

    Exact mathematical passage
    
    V_j=\lambda_j^{-1/2}F_jP
    
\lambda_{k,h}Use in source · 9 passages

Search aliases: λ_k,h lambda

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  • Use in source · monograph_atlas.tex, line 461

    vpage25Refine the grid while holding the mode fixedAN EXACT ERROR ENCLOSURE, NOT A FITTED SLOPETraditional edition: Theorem II.11.4. For the circle symbol, the continuum value is k^2 and the grid value is λ_k,h=frac4h^2sin^2 (frackh2), h≠0. For a fixed low mode, the paper bounds the error by 0≤ k^2-λ_k,h≤ k^4h^2/12. The spacing condition matters because the displayed expression divides by h^2. vfigdispersion headWhat is certified in the displayed table? Take k=1 and h=1/4,1/8,1/16. For x=h/2∈[0,…

    Exact mathematical passage
    
    \lambda_{k,h}=\frac4{h^2}\sin^2\!\left(\frac{kh}{2}\right),\qquad h\ne0.
    
\lambda_{\min}Use in source · 1 passage

Search aliases: λ_min lambda min

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  • Use in source · Read passage · 01_finite_core.tex, line 1131

    d_s(τ) is a diagnostic, not a topological invariant. Indeed, finite differentiation gives d_s(τ)=2τ frac∑_jλ_j e^-τλ_j∑_j e^-τλ_j. It tends to zero as τdownarrow0 and, under the stated assumption of a zero mode, as τ→∞. If a general positive operator has no zero mode, its behavior at large times is instead asymptotic to 2τλ_min. The conclusion for operators with a zero mode therefore does not apply to that case. Inferring a geometric dimension requires a stable intermediate window and a controll…

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    2\tau\lambda_{\min}
\Lambda_NUse in source · 1 passage

Search aliases: Λ_N Lambda

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  • Use in source · Read passage · 02_strengthened.tex, line 2021

    Let N≥2 and let Λ_N=( Z/N Z)^d be the unit flat torus grid with spacing 1/N. The standard periodic difference Laplacian has eigenvalues λ_N(k) = 4N^2 ∑_j=1^d sin^2(fracπ k_jN), where k runs through centered residue representatives. This is the standard periodic finite difference Laplacian [source reference].

    Exact mathematical passage
    \Lambda_N=(\ZZ/N\ZZ)^d
\Lambda_N^*Use in source · 2 passages

Search aliases: Λ_N^* Lambda

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  • Use in source · Read passage · 02_strengthened.tex, line 2061

    [Fixed time heat trace convergence] For every t>0, ∑_k∈Λ_N^* e^-tλ_N(k) ⟶ ∑_k∈ Z^d e^-4π^2tabsk^2 as N→∞. The first spectral moments also converge: ∑_k∈Λ_N^* λ_N(k) e^-tλ_N(k) ⟶ ∑_k∈ Z^d 4π^2absk^2 e^-4π^2tabsk^2. Consequently, the discrete spectral dimensions converge to the continuum torus spectral dimension at every fixed positive time.

    Exact mathematical passage
    
    \sum_{k\in\Lambda_N^*}
    \e^{-t\lambda_N(k)}
    \longrightarrow
    \sum_{k\in\ZZ^d}
    \e^{-4\pi^2t\abs{k}^2}
    
\lambda_rUse in source · 12 passages

Search aliases: λ_r lambda

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  • Use in source · Read passage · 01_finite_core.tex, line 842

    textitSufficiency. Diagonalize C=Udiag(λ_r)U^* with U unitary and λ_r≥0. Define compressed transformed errors F_r=∑_aU_arE_aP. Then F_rP=F_r and F_r^*F_s=λ_rδ_rsP. If λ_r=0, F_r^*F_r=0 forces F_r=0. For positive eigenvalues only, set V_r=F_r/sqrtλ_r. These satisfy V_rP=V_r, V_r^*V_s=δ_rsP. Let S=∑_λ_r>0V_rV_r^*. Orthogonality makes S an orthogonal projector. Use the recovery branches K_r=V_r^*, K_unused=I-S. They are complete on the whole ambient space because ∑_rK_r^*K_r+K_unused^*K_unused =S+(…

    Exact mathematical passage
    C=U\operatorname{diag}(\lambda_r)U^*
\lambda_r^{-1/2}Use in source · 1 passage

Search aliases: λ_r^-1/2 lambda

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  • Use in source · Read passage · 03_supplement_05.tex, line 61

    Null directions are removed by proof. If λ_r=0, then B_r^*B_r=0. Positivity of the ordinary complex matrix inner product gives B_r=0. This is the checked declaration pathDiagonalErrors.zero_weight_error. The normalized syndrome operators are defined only on A_+={r:λ_r>0}, V_r=λ_r^-1/2B_r. Consequently no inverse square root at a null eigenvalue is needed. Lean proves V_rP=V_r, V_r^*V_s=δ_rsP. The previous block's recovery is now instantiated from these derived syndromes, rather than from an assu…

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    A_+=\{r:\lambda_r>0\},\qquad V_r=\lambda_r^{-1/2}B_r.
    
\muUse in source · 7 passages

Search aliases: μ mu

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  • Use in source · Read passage · 01_finite_core.tex, line 632

    For an orthogonal rank-one complex projector, use the scalar connection convention A=-i⟨ u,du⟩ in a local unit frame. The associated scalar curvature density is F_μν =-iTr(P[∂_μ P,∂_ν P]). On the Bloch sphere, P(θ,ϕ) = frac12(I+ n(θ,ϕ)·σ), where n=(sinθcosϕ,sinθsinϕ,cosθ). The Pauli multiplication law gives [∂_θ P,∂_ϕ P] =fraci2(∂_θ nmathbin×∂_ϕ n)·σ. Using Tr(P a·σ)= n· a therefore yields F_θϕ =frac12 n·(∂_θ nmathbin×∂_ϕ n) =frac12sinθ. The scalar sign changes if the opposite convention for A i…

    Exact mathematical passage
    
    \cF_{\mu\nu}
    =-i\Tr\left(P[\partial_\mu P,\partial_\nu P]\right).
    
\nuUse in source · 1 passage

Search aliases: ν nu

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  • Use in source · Read passage · 01_finite_core.tex, line 632

    For an orthogonal rank-one complex projector, use the scalar connection convention A=-i⟨ u,du⟩ in a local unit frame. The associated scalar curvature density is F_μν =-iTr(P[∂_μ P,∂_ν P]). On the Bloch sphere, P(θ,ϕ) = frac12(I+ n(θ,ϕ)·σ), where n=(sinθcosϕ,sinθsinϕ,cosθ). The Pauli multiplication law gives [∂_θ P,∂_ϕ P] =fraci2(∂_θ nmathbin×∂_ϕ n)·σ. Using Tr(P a·σ)= n· a therefore yields F_θϕ =frac12 n·(∂_θ nmathbin×∂_ϕ n) =frac12sinθ. The scalar sign changes if the opposite convention for A i…

    Exact mathematical passage
    
    \cF_{\mu\nu}
    =-i\Tr\left(P[\partial_\mu P,\partial_\nu P]\right).
    
\PiUse in source · 5 passages

Search aliases: Π Pi

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  • Use in source · Read passage · 01_finite_core.tex, line 1003

    At resolution ℓ, define Q_ℓ = ( A_ℓ, H_ℓ, D_ℓ, {P_ℓ,α}, E_ℓ, C_ℓ, Π_ℓ^phys, T_ℓ ). In order, the entries specify the observable algebra, Hilbert space, geometric or Dirac-type operator, packet projectors, embedding into the fine space, reconstruction onto the coarse space, physical constraint projector, and transfer operator. The maps have types E_ℓ: H_ℓ→ H_ℓ+1 and C_ℓ: H_ℓ+1→ H_ℓ. The left inverse relation C_ℓ E_ℓ=I alone does not imply C_ℓ=E_ℓ^* or make the embedding isometric.

    Exact mathematical passage
    
    \boxed{
    \mathfrak Q_\ell
    =
    \left(
    \cA_\ell,
    \cH_\ell,
    D_\ell,
    \{P_{\ell,\alpha}\},
    E_\ell,
    C_\ell,
    \Pi_\ell^{\mathrm{phys}},
    T_\ell
    \right).
    }
    
\pi^2Use in source · 9 passages

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  • Use in source · monograph_atlas.tex, line 471

    Each interval lies strictly inside (0,h^2/12). Dividing successive interval endpoints proves that both error ratios are between 3.99 and 4. The check verifies these inequalities by rational arithmetic, without relying on approximate sine values or a fitted logarithmic slope. headWhy the mode regime matters If instead k=π/h moves with the grid, the ratio λ_k,h/k^2=4/π^2 stays constant, not one. The bound's factor k^4 warns that it is not uniform in arbitrary moving high modes. The displayed ratio…

    Exact mathematical passage
    \lambda_{k,h}/k^2=4/\pi^2
\pi^4Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 2033

    [Low mode dispersion in dimension d] For every centered mode k, 0 ≤ 4π^2absk^2-λ_N(k) ≤ frac4π^43N^2 ∑_j=1^dk_j^4.

    Exact mathematical passage
    
    0
    \leq
    4\pi^2\abs{k}^2-\lambda_N(k)
    \leq
    \frac{4\pi^4}{3N^2}
    \sum_{j=1}^{d}k_j^4.
    
\Pi^{\mathrm{phys}}Use in source · 4 passages

Search aliases: Π^phys Pi mathrm

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  • Use in source · Read passage · 01_finite_core.tex, line 1198

    At one finite level, let widehat C_A be a finite family of matrix constraints, with fixed scalar structure coefficients, and let Π^phys be the orthogonal projector onto their exact common kernel. If the classical constraint algebra has structure coefficients f_AB^ C, define the anomaly operator A_AB = [widehat C_A,widehat C_B] -i∑_C f_AB^ Cwidehat C_C. Its physical packet is Π^phys A_ABΠ^phys. In this exact finite setting, widehat C_CΠ^phys=0 for every C. Associativity gives A_ABΠ^phys=0, Π^phys…

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    \Pi^{\mathrm{phys}}
\pi_\lambdaUse in source · 2 passages

Search aliases: π_λ pi lambda

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  • Use in source · Read passage · 02_strengthened.tex, line 242

    [Representation matrix units] Fix an irreducible unitary representation π_λ:G→ U(d_λ) and an orthonormal basis of its representation space. Define E_ij^λ = fracd_λabsG ∑_g∈ G [π_λ(g^-1)]_jiU(g). Then E_ij^λE_kℓ^μ = δ_λμδ_jkE_iℓ^λ, (E_ij^λ)^*=E_ji^λ, and P_λ=∑_i=1^d_λE_ii^λ.

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    \pi_\lambda:G\to U(d_\lambda)
\pi_\muUse in source · 2 passages

Search aliases: π_μ pi mu

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  • Use in source · Read passage · 02_strengthened.tex, line 225

    Complete reducibility gives a unitary decomposition H ≅ ⊕_μ∈widehat G V_μ⊗ M_μ, U(g) ≅ ⊕_μ π_μ(g)⊗ I_M_μ. On the μ summand, the displayed average is central in the irreducible representation π_μ, so it is a scalar by Schur's lemma. Taking its trace and applying character orthogonality shows that the scalar is one when μ=λ and zero otherwise. The asserted identities follow on the direct sum.

    Exact mathematical passage
    
    \Hcal
    \cong
    \bigoplus_{\mu\in\widehat G}
    V_\mu\otimes M_\mu,
    \qquad
    U(g)
    \cong
    \bigoplus_\mu
    \pi_\mu(g)\otimes I_{M_\mu}.
    
\Pi_\ell^{\mathrm{phys}}Use in source · 1 passage

Search aliases: Π_ℓ^phys Pi ell mathrm

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  • Use in source · Read passage · 01_finite_core.tex, line 1003

    At resolution ℓ, define Q_ℓ = ( A_ℓ, H_ℓ, D_ℓ, {P_ℓ,α}, E_ℓ, C_ℓ, Π_ℓ^phys, T_ℓ ). In order, the entries specify the observable algebra, Hilbert space, geometric or Dirac-type operator, packet projectors, embedding into the fine space, reconstruction onto the coarse space, physical constraint projector, and transfer operator. The maps have types E_ℓ: H_ℓ→ H_ℓ+1 and C_ℓ: H_ℓ+1→ H_ℓ. The left inverse relation C_ℓ E_ℓ=I alone does not imply C_ℓ=E_ℓ^* or make the embedding isometric.

    Exact mathematical passage
    
    \boxed{
    \mathfrak Q_\ell
    =
    \left(
    \cA_\ell,
    \cH_\ell,
    D_\ell,
    \{P_{\ell,\alpha}\},
    E_\ell,
    C_\ell,
    \Pi_\ell^{\mathrm{phys}},
    T_\ell
    \right).
    }
    
\rho_+Use in source · 2 passages

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  • Use in source · monograph_atlas.tex, line 320

    For ρ_+=frac12mat1 · 1 1 · 1, the exact output is Φ(ρ_+)=mat17/25 · 2/5

    Exact mathematical passage
    \rho_+=\frac12\mat{1&1\\1&1}
\rho_0Use in source · 2 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 1385

    The map R_0 is completely positive. It is trace preserving on operators supported in Q H because Tr(V_j^*Q_jXQ_jV_j) = Tr(Q_jXQ_j). Fix a code state ρ_0 and write Q^⊥=I-Q. Then R(X) = R_0(QXQ) + Tr(Q^⊥ X)ρ_0 is completely positive and trace preserving. It extends R_0 on operators supported in Q H.

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    \rho_0
\rho_{00}Use in source · 1 passage

Search aliases: ρ_00 rho

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  • Use in source · monograph_atlas.tex, line 318

    0 · 0, K_0^*K_0+K_1^*K_1=I. The channel Φ(ρ)=∑_aK_aρ K_a^* is trace preserving and completely positive. The special parameter keeps every displayed coefficient rational. vfigdamping The superoperator uses the entry order (ρ_00,ρ_01,ρ_10,ρ_11). Population leaves the excited state with factor 9/25, while coherences contract by 4/5. These are not the same rate or the same coordinate.

    Exact mathematical passage
    (\rho_{00},\rho_{01},\rho_{10},\rho_{11})
\rho_{01}Use in source · 1 passage

Search aliases: ρ_01 rho

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  • Use in source · monograph_atlas.tex, line 318

    0 · 0, K_0^*K_0+K_1^*K_1=I. The channel Φ(ρ)=∑_aK_aρ K_a^* is trace preserving and completely positive. The special parameter keeps every displayed coefficient rational. vfigdamping The superoperator uses the entry order (ρ_00,ρ_01,ρ_10,ρ_11). Population leaves the excited state with factor 9/25, while coherences contract by 4/5. These are not the same rate or the same coordinate.

    Exact mathematical passage
    (\rho_{00},\rho_{01},\rho_{10},\rho_{11})
\rho_{10}Use in source · 1 passage

Search aliases: ρ_10 rho

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  • Use in source · monograph_atlas.tex, line 318

    0 · 0, K_0^*K_0+K_1^*K_1=I. The channel Φ(ρ)=∑_aK_aρ K_a^* is trace preserving and completely positive. The special parameter keeps every displayed coefficient rational. vfigdamping The superoperator uses the entry order (ρ_00,ρ_01,ρ_10,ρ_11). Population leaves the excited state with factor 9/25, while coherences contract by 4/5. These are not the same rate or the same coordinate.

    Exact mathematical passage
    (\rho_{00},\rho_{01},\rho_{10},\rho_{11})
\rho_{11}Use in source · 1 passage

Search aliases: ρ_11 rho

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  • Use in source · monograph_atlas.tex, line 318

    0 · 0, K_0^*K_0+K_1^*K_1=I. The channel Φ(ρ)=∑_aK_aρ K_a^* is trace preserving and completely positive. The special parameter keeps every displayed coefficient rational. vfigdamping The superoperator uses the entry order (ρ_00,ρ_01,ρ_10,ρ_11). Population leaves the excited state with factor 9/25, while coherences contract by 4/5. These are not the same rate or the same coordinate.

    Exact mathematical passage
    (\rho_{00},\rho_{01},\rho_{10},\rho_{11})
\rho_{\rm Bell}Use in source · 3 passages

Search aliases: ρ_rm Bell rho rm

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  • Use in source · monograph_atlas.tex, line 333

    lassical input II.7.7. Ordinary transpose T sends a positive matrix on one system to another positive matrix and preserves its trace. Those properties are insufficient for a quantum channel on a subsystem of an entangled state. The test must include id⊗ T on the larger system. vfigcomplete_positivity Apply this extended map to the Bell density matrix. The result is (id⊗ T)(ρ_rm Bell) =frac12mat1 · 0 · 0 · 0 0 · 0 · 1 · 0 0 · 1 · 0 · 0 0 · 0 · 0 · 1. Its middle block has one negative eigenvalue. …

    Exact mathematical passage
    
    (\id\otimes\mathsf T)(\rho_{\rm Bell})
    =\frac12\mat{1&0&0&0\\0&0&1&0\\0&1&0&0\\0&0&0&1}.
    
\rho_\etaUse in source · 1 passage

Search aliases: ρ_η rho eta

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  • Use in source · monograph_atlas.tex, line 503

    actual amplitude vector is (- i,1, i,1)^T/2, giving uniform site probabilities. The subsequent phases recombine those four amplitudes into a single output at the opposite site. Uniform intermediate probabilities do not imply an incoherent intermediate state. headA channel changes the conclusion predictably Before evolving, mix the seed density matrix with its complete momentum dephasing: ρ_η=(1-η)ket0bra0+η∑_jP_jket0bra0P_j =(1-η)ket0bra0+η I/4, quad0≤η≤1. At transfer time, the probability at th…

    Exact mathematical passage
    
    \rho_\eta=(1-\eta)\ket0\bra0+\eta\sum_jP_j\ket0\bra0P_j
    =(1-\eta)\ket0\bra0+\eta I/4,
    \quad0\le\eta\le1.
    
\bm\sigmaUse in source · 2 passages

Search aliases: σ bm sigma

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  • Use in source · Read passage · 02_strengthened.tex, line 891

    [Bloch sphere curvature] Let P(θ,ϕ) = frac12(I+ n(θ,ϕ)·σ), where n=(sinθcosϕ,sinθsinϕ,cosθ). With the convention F_θϕ =- iTr(P[∂_θ P,∂_ϕ P]), one has F_θϕ=frac12sinθ and frac12π ∫_0^2π∫_0^π F_θϕ dθ dϕ =1.

    Exact mathematical passage
    
    P(\theta,\phi)
    =
    \frac12\left(I+\bm n(\theta,\phi)\cdot\bm\sigma\right),
    
\boldsymbol\sigmaUse in source · 3 passages

Search aliases: σ boldsymbol sigma

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  • Use in source · Read passage · 01_finite_core.tex, line 637

    For an orthogonal rank-one complex projector, use the scalar connection convention A=-i⟨ u,du⟩ in a local unit frame. The associated scalar curvature density is F_μν =-iTr(P[∂_μ P,∂_ν P]). On the Bloch sphere, P(θ,ϕ) = frac12(I+ n(θ,ϕ)·σ), where n=(sinθcosϕ,sinθsinϕ,cosθ). The Pauli multiplication law gives [∂_θ P,∂_ϕ P] =fraci2(∂_θ nmathbin×∂_ϕ n)·σ. Using Tr(P a·σ)= n· a therefore yields F_θϕ =frac12 n·(∂_θ nmathbin×∂_ϕ n) =frac12sinθ. The scalar sign changes if the opposite convention for A i…

    Exact mathematical passage
    
    P(\theta,\phi)
    =
    \frac12\left(I+\mathbf n(\theta,\phi)\cdot\boldsymbol\sigma\right),
    
\Sigma'Use in source · 2 passages

Search aliases: Σ' Sigma

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  • Use in source · Read passage · 02_strengthened.tex, line 1608

    [Uniform self energy bounds] Let δ=dist(z,Spec D)>0, g=norm B. Then normΣ(z)≤fracg^2δ and normΣ'(z)≤fracg^2δ^2. For real E,E' in an interval at distance at least δ from Spec D, normΣ(E)-Σ(E') ≤ fracg^2δ^2absE-E'.

    Exact mathematical passage
    
    \norm{\Sigma'(z)}\leq\frac{g^2}{\delta^2}.
    
\sigma_aUse in source · 2 passages

Search aliases: σ_a sigma

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  • Use in source · monograph_atlas.tex, line 746

    vpage38Transport constraints without hiding closureTHE IMAGE OF AN ISOMETRY IS NOT THE WHOLE LEVELTraditional edition: Theorem II.12.2, Theorem II.12.5, Proposition II.12.6. On C^3= Cket0⊕ C^2, use C_a=0⊕σ_a for a=x,y,z. The common kernel is Cket0, and the full algebra closes: [C_x,C_y]=2 i C_z, [C_y,C_z]=2 i C_x, [C_z,C_x]=2 i C_y. These are uncompressed identities. They supply an actual closure test in the quotient by the constraint span, unlike the automatic compressed zero on the physical ke…

    Exact mathematical passage
    C_a=0\oplus\sigma_a
\Sigma_PUse in source · 2 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 937

    The self-energy Σ_P(z) =H_PQ(z-H_QQ)^-1H_QP contains the complete influence of the eliminated packet. Bare truncation drops Σ_P(z) and is therefore exact only when the coupling between packets vanishes or the self-energy cancels for another stated reason.

    Exact mathematical passage
    
    \Sigma_P(z)
    =H_{PQ}(z-H_{QQ})^{-1}H_{QP}
    
\phiUse in source · 21 passages

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  • Use in source · monograph_atlas.tex, line 272

    vpage15Curvature measures a local area responseAN EXACT BLOCH PROJECTOR CALCULATIONTraditional edition: Theorem II.6.7, Corollary II.6.8. On the unit sphere, set n=(sinθcosϕ,sinθsinϕ,cosθ) and P(θ,ϕ)=frac12(I+n·σ). This is a smooth rank-one orthogonal projector. The intrinsic curvature is the endomorphism-valued two-form P( d Pwedge d P)P. With the paper's scalar convention, its component is F_θϕ=- iTr (P[∂_θ P,∂_ϕ P]) =frac12sinθ. vfigbloch_curvature headA local frame gives the same answer Away…

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    n=(\sin\theta\cos\phi,\sin\theta\sin\phi,\cos\theta)
\Phi^{(J)}Use in source · 2 passages

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  • Use in source · Read passage · 03_supplement_02.tex, line 206

    To prove complete positivity rather than positivity alone, let J be an arbitrary finite auxiliary index set. For a matrix X indexed by J× n, define its blockwise amplification by [Φ^(J)(X)]_(i,u),(j,v) =Φ(X_(i,·),(j,·))_u,v. The explicit index calculation proves the identity Φ^(J)(X)=∑_a (I_J⊗ K_a)X(I_J⊗ K_a)^*. The displayed identity identifies the defined amplification with tensoring by the identity, which is the operation needed for complete positivity. Every summand on the right is positive …

    Exact mathematical passage
    
     [\Phi^{(J)}(X)]_{(i,u),(j,v)}
     =\Phi\bigl(X_{(i,\cdot),(j,\cdot)}\bigr)_{u,v}.
    
\Phi^+Use in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 294

    vpage16Which coherence can a measurement see?THE ANSWER DEPENDS ON ITS EFFECTSTraditional edition: Theorem II.7.2, Theorem II.7.4, Corollary II.7.5. For the Bell density matrix ρ=ketΦ^+braΦ^+, parity dephasing does nothing: both nonzero amplitudes already lie in the even subspace. Dephasing in the computational basis removes the entries between addresses 00 and 11. vfigdephasing Every effect in the computational basis E_a=ket abra a has the same expectation on both matrices, namely 1/2 at 00 and…

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    \rho=\ket{\Phi^+}\bra{\Phi^+}
\Phi_{cd,ab}Use in source · 3 passages

Search aliases: Φ_cd,ab Phi

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  • Use in source · Read passage · 02_strengthened.tex, line 1043

    Let Φ:End( H_X)→End( H_Y) be linear. Choose packet systems (P_a) on H_X and (Q_c) on H_Y. Define Φ_cd,ab = Q_cdΦ P_ab.

    Exact mathematical passage
    
    \Phi_{cd,ab}
    =
    \Qcal_{cd}\Phi\Pcal_{ab}.
    
\Phi_{\alpha\beta;\gamma\delta}Use in source · 1 passage

Search aliases: Φ_αβ;γδ Phi alpha beta gamma delta

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  • Use in source · Read passage · 01_finite_core.tex, line 751

    Packet superoperator blocks are defined by Φ_αβ;γδ(X) = P_α Φ(P_γ XP_δ) P_β. Summing all four packet indices reconstructs Φ(X) exactly.

    Exact mathematical passage
    
    \Phi_{\alpha\beta;\gamma\delta}(X)
    =
    P_\alpha
    \Phi(P_\gamma XP_\delta)
    P_\beta.
    
\Phi_\gammaUse in source · 1 passage

Search aliases: Φ_γ Phi gamma

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  • Use in source · Read passage · 02_strengthened.tex, line 1196

    0 · 0 . The channel Φ_γ(ρ)=K_0ρ K_0^*+K_1ρ K_1^* is trace preserving. It sends the off diagonal packet ket0bra1 to sqrt1-γket0bra1, while the excited population transfers partly into the ground population.

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    \Phi_\gamma(\rho)=K_0\rho K_0^*+K_1\rho K_1^*
    
\PsiUse in source · 4 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 1239

    [Einstein infrared limit] There exist semiclassical packet states Ψ_g,ℓ such that the effective action converges to frac116π G ∫sqrt-g (R-2Λ) d^4x with controlled higher-order corrections.

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    \Psi_{g,\ell}
\psi^*Use in source · 5 passages

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  • Use in source · monograph_atlas.tex, line 10

    to follow when its objects remain visible. This appendix follows a state vector, a density matrix, and a retained part of a dynamical system. They may describe the same experiment, but they do not answer the same question. vfigthree_objects headAmplitudes retain relative phase For the Bell vector ψ=(ket00+ket11)/sqrt2, the two nonzero entries are amplitudes. The density matrix ρ=ψψ^* also records coherence in its off-diagonal entries. Measurements that compare the two addresses can detect this c…

    Exact mathematical passage
    \rho=\psi\psi^*
\Psi_{ef,cd}Use in source · 1 passage

Search aliases: Ψ_ef,cd Psi

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  • Use in source · Read passage · 02_strengthened.tex, line 1055

    [Exact channel block calculus] Every linear map has the exact reconstruction Φ=∑_a,b,c,dΦ_cd,ab. If Ψ:End( H_Y)→End( H_Z), then (ΨΦ)_ef,ab = ∑_c,d Ψ_ef,cdΦ_cd,ab.

    Exact mathematical passage
    
    (\Psi\Phi)_{ef,ab}
    =
    \sum_{c,d}
    \Psi_{ef,cd}\Phi_{cd,ab}.
    
\Psi_{g,\ell}Use in source · 1 passage

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  • Use in source · Read passage · 01_finite_core.tex, line 1239

    [Einstein infrared limit] There exist semiclassical packet states Ψ_g,ℓ such that the effective action converges to frac116π G ∫sqrt-g (R-2Λ) d^4x with controlled higher-order corrections.

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    \Psi_{g,\ell}
\psi_iUse in source · 1 passage

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  • Use in source · Read passage · 01_finite_core.tex, line 92

    A ≅ ⊕_i=1^r (M_d_i( C)⊗ I_m_i) on H ≅ ⊕_i=1^r ( C^d_i⊗ C^m_i). Here every d_i is a positive integer and every multiplicity m_i is a nonnegative integer. An empty block family represents the zero space and has seed rank zero. The maximum over an empty block family is also assigned the value zero. A vector ψ_i∈ C^d_i⊗ C^m_i is identified with a d_i× m_i coefficient matrix C_i.

    Exact mathematical passage
    \psi_i\in\bbC^{d_i}\otimes\bbC^{m_i}
\OmegaUse in source · 6 passages

Search aliases: Ω Omega

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  • Use in source · Read passage · 02_strengthened.tex, line 1158

    Let Ω=∑_iketi⊗keti. Then J(Φ)=(Φ⊗id)(ketΩbraΩ). The vector Ω is invariant under U⊗overline U. Covariance therefore implies the displayed Choi invariance. Conversely, the displayed transformation is the Choi matrix of Ad_U(g)∘Φ∘Ad_U(g)^*. The Choi correspondence is injective, so invariance implies that this map equals Φ, which is covariance.

    Exact mathematical passage
    
    \Omega=\sum_i\ket{i}\otimes\ket{i}.
    
\omega^{(k-j)r}Use in source · 1 passage

Search aliases: ω^(k-j)r omega

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  • Use in source · Read passage · 01_finite_core.tex, line 217

    Using S^r+s=S^r+sbmod N and the finite character orthogonality relation, frac1N∑_r=0^N-1ω^(k-j)r=δ_jk, we obtain P_jP_k=δ_jkP_j. Summing over j cancels every term indexed by r≠0 and retains the r=0 term, which proves completeness. Unitarity and the change of residue r↦-r give P_j^*=frac1N∑_r=0^N-1ω^jrS^-r=P_j. Finally, multiplication by S shifts the summation index and contributes the factor ω^j.

    Exact mathematical passage
    
    \frac1N\sum_{r=0}^{N-1}\omega^{(k-j)r}=\delta_{jk},
    
\omega^{-jr}Use in source · 2 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 196

    [Cyclic quantum projectors] The operators P_j = frac1N∑_r=0^N-1ω^-jrS^r, 0≤ j<N, are self-adjoint, pairwise orthogonal projectors satisfying P_jP_k=δ_jkP_j, ∑_j=0^N-1P_j=I, SP_j=ω^jP_j.

    Exact mathematical passage
    
    \boxed{
    P_j
    =
    \frac1N\sum_{r=0}^{N-1}\omega^{-jr}S^r,
    \qquad
    0\le j<N,
    }
    
\omega^{-qr}Use in source · 1 passage

Search aliases: ω^-qr omega

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  • Use in source · Read passage · 02_strengthened.tex, line 1099

    [Coherence order projectors] For q∈ Z/N Z, define L_q(X) = frac1N ∑_r=0^N-1 ω^-qrS^rXS^-r. Then the L_q form a complete orthogonal packet system on Hilbert Schmidt operator space. Their ranges are the operators satisfying SXS^*=ω^qX. If P_j are the state charge projectors, then Ran L_q = ⊕_jP_j+qEnd( H)P_j.

    Exact mathematical passage
    
    \Lcal_q(X)
    =
    \frac1N
    \sum_{r=0}^{N-1}
    \omega^{-qr}S^rXS^{-r}.
    
\omega^jUse in source · 4 passages

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  • Use in source · Read passage · 01_finite_core.tex, line 206

    [Cyclic quantum projectors] The operators P_j = frac1N∑_r=0^N-1ω^-jrS^r, 0≤ j<N, are self-adjoint, pairwise orthogonal projectors satisfying P_jP_k=δ_jkP_j, ∑_j=0^N-1P_j=I, SP_j=ω^jP_j.

    Exact mathematical passage
    
    P_jP_k=\delta_{jk}P_j,
    \qquad
    \sum_{j=0}^{N-1}P_j=I,
    \qquad
    SP_j=\omega^jP_j.
    
\omega^{jr}Use in source · 2 passages

Search aliases: ω^jr omega

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  • Use in source · Read passage · 01_finite_core.tex, line 221

    Using S^r+s=S^r+sbmod N and the finite character orthogonality relation, frac1N∑_r=0^N-1ω^(k-j)r=δ_jk, we obtain P_jP_k=δ_jkP_j. Summing over j cancels every term indexed by r≠0 and retains the r=0 term, which proves completeness. Unitarity and the change of residue r↦-r give P_j^*=frac1N∑_r=0^N-1ω^jrS^-r=P_j. Finally, multiplication by S shifts the summation index and contributes the factor ω^j.

    Exact mathematical passage
    
    P_j^*=\frac1N\sum_{r=0}^{N-1}\omega^{jr}S^{-r}=P_j.
    
\omega^{q+j}Use in source · 1 passage

Search aliases: ω^q+j omega

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  • Use in source · Read passage · 02_strengthened.tex, line 313

    For x∈ P_j H, S(Ax) =(SAS^*)Sx =ω^q+jAx. Thus Ax∈ P_j+q H. The block statement follows.

    Exact mathematical passage
    
    S(Ax)
    =(SAS^*)Sx
    =\omega^{q+j}Ax.
    
\omega^{q_r}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 1237

    [Charge preservation by a Lindblad generator] Let S be unitary and N≥1 an integer with S^N=I. Assume SHS^*=H and, for every jump operator, there is a charge q_r such that SL_rS^*=ω^q_rL_r. Then the Lindblad generator G preserves every coherence order: G L_p= L_p G. The quantum dynamical semigroup e^t G has the same property.

    Exact mathematical passage
    
    SL_rS^*=\omega^{q_r}L_r.
    
\omega^{\operatorname{val}(r)}Use in source · 1 passage

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  • Use in source · Read passage · 03_supplement_03.tex, line 93

    Constructed cyclic character projectors. Let N>0 and let S be a unitary complex matrix with S^N=I. The implementation uses the standard additive character of Z/N Z and proves its expression through a root of unity: ω=exp(2π i/N), χ(r)=ω^val(r). Here val(r) is the canonical representative in {0,…,N-1}. The representation is constructed as ρ(r)=S^val(r). Reduction of exponents modulo N is proved from S^N=I, giving ρ(r+s)=ρ(r)ρ(s) and ρ(0)=I. The final matrix theorem derives the representation law …

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    \omega=\exp(2\pi i/N),\qquad
    \chi(r)=\omega^{\operatorname{val}(r)}.
    
\omega^{\operatorname{val}(r)\operatorname{val}(j)}Use in source · 1 passage

Search aliases: ω^val(r)val(j) omega operatorname operatorname

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  • Use in source · Read passage · 03_supplement_03.tex, line 109

    Exact coefficient formula. The packet definition is a finite sum over residue classes: P_j=frac1N∑_r∈ Z/N Zχ(-rj)ρ(r). The source proves χ(-rj)=(ω^val(r)val(j))^-1, so this is precisely the manuscript's N-term Fourier projector formula, with canonical representatives.

    Exact mathematical passage
    
    \chi(-rj)=\bigl(\omega^{\operatorname{val}(r)\operatorname{val}(j)}\bigr)^{-1},
    
\ell^2Use in source · 2 passages

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  • Use in source · monograph_atlas.tex, line 769

    a bounded Hamiltonian limitEXACT EMBEDDINGS AND A SUMMABLE TAILTraditional edition: Theorem II.13.2, Theorem II.13.4, Corollary II.13.5. For the exact route, let HH_n= C^n with coordinate inclusions and H_n=diag(0,1,1/2,…,1/(n-1)), H_1=(0). The old energies are retained at every level, H_n+1R_n=R_nH_n, and normH_n≤1. On the Hilbert space of the direct limit ℓ^2( N_0), the diagonal sequence defines a bounded self-adjoint H_∞. Projectors onto even addresses also intertwine and give a fixed complet…

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    \ell^2(\NN_0)
\toUse in source · 31 passages

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  • Use in source · monograph_atlas.tex, line 452

    ues are 0,2,2,4. The normalized heat trace and its diagnostic of spectral dimension are therefore K(τ)=frac1+2e^-2τ+e^-4τ4 =frac(1+e^-2τ)^24, d_s(τ)=-2τfracK'(τ)K(τ) =frac8τe^2τ+1. No numerical differentiation is needed for this finite example. vfigspectral_dimension headBoth ends reflect the finite size of the system As τ→0, every eigenmode contributes approximately one and the dimension diagnostic tends to zero. As τ→∞, the zero mode dominates, so it again tends to zero. A finite spectrum cann…

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    \tau\to0
\mapstoUse in source · 8 passages

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  • Use in source · monograph_atlas.tex, line 580

    vpage31Coherence order survives a covariant channelCHANNEL, CHOI, AND GENERATOR CHECKSTraditional edition: Theorem II.7.8, Theorem II.7.10, Theorem II.7.14. Take S=Z=diag(1,-1) on C^2. Under conjugation X↦ ZXZ, diagonal matrices have coherence order zero and off-diagonal matrices have coherence order one modulo two. Its projectors on Hilbert--Schmidt operator space are L_0(X)=(X+ZXZ)/2 and L_1(X)=(X-ZXZ)/2.

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    X\mapsto ZXZ
\RightarrowUse in source · 1 passage

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  • Use in source · Read passage · 03_supplement_05.tex, line 101

    a row. If X is the matrix of those rows and p is the vector of entries of P, the resulting Gram identity is X^*X=overline p p^ T. The checked rank-one Gram lemma proves that every row of X is proportional to p. For nonzero p, a nonzero coordinate is selected and a test vector supported on two coordinates is placed in the null space of the Gram matrix. The implication X^*Xv=0⇒ Xv=0 then gives the required proportionality. When p=0, the Gram identity forces X=0 directly.

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    X^*Xv=0\Rightarrow Xv=0
\forallUse in source · 1 passage

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  • Use in source · Read passage · 03_supplement_03.tex, line 18

    Several seeds: both necessity and construction. Continue under the assumption above that the number of rows is positive. For seeds C_1,…,C_k, generation means the concrete statement ∀ X∈ M_d× m( C), ∃ A_1,…,A_k∈ M_d( C): X=∑_a=1^k A_aC_a. Stack the C_a vertically into a kd× m matrix D. The source identifies the action on the stacked matrix and proves the equivalence the seeds generate Longleftrightarrow rank D=m. Thus m≤ kd is necessary. It is sufficient as well: embed the m coordinate columns i…

    Exact mathematical passage
    
    \forall X\in M_{d\times m}(\C),\quad
    \exists A_1,\ldots,A_k\in M_d(\C):\quad
    X=\sum_{a=1}^k A_aC_a.
    
\partialUse in source · 6 passages

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  • Use in source · monograph_atlas.tex, line 277

    LOCH PROJECTOR CALCULATIONTraditional edition: Theorem II.6.7, Corollary II.6.8. On the unit sphere, set n=(sinθcosϕ,sinθsinϕ,cosθ) and P(θ,ϕ)=frac12(I+n·σ). This is a smooth rank-one orthogonal projector. The intrinsic curvature is the endomorphism-valued two-form P( d Pwedge d P)P. With the paper's scalar convention, its component is F_θϕ=- iTr (P[∂_θ P,∂_ϕ P]) =frac12sinθ. vfigbloch_curvature headA local frame gives the same answer Away from the south pole, use u_N=(cos(θ/2),e^ iϕsin(θ/2))^T.…

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    F_{\theta\phi}=-\ii\Tr\!\left(P[\partial_\theta P,\partial_\phi P]\right)
    =\frac12\sin\theta.
    
\partial_\thetaUse in source · 5 passages

Search aliases: ∂_θ partial theta

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  • Use in source · monograph_atlas.tex, line 277

    LOCH PROJECTOR CALCULATIONTraditional edition: Theorem II.6.7, Corollary II.6.8. On the unit sphere, set n=(sinθcosϕ,sinθsinϕ,cosθ) and P(θ,ϕ)=frac12(I+n·σ). This is a smooth rank-one orthogonal projector. The intrinsic curvature is the endomorphism-valued two-form P( d Pwedge d P)P. With the paper's scalar convention, its component is F_θϕ=- iTr (P[∂_θ P,∂_ϕ P]) =frac12sinθ. vfigbloch_curvature headA local frame gives the same answer Away from the south pole, use u_N=(cos(θ/2),e^ iϕsin(θ/2))^T.…

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    F_{\theta\phi}=-\ii\Tr\!\left(P[\partial_\theta P,\partial_\phi P]\right)
    =\frac12\sin\theta.
    
\partial_\muUse in source · 1 passage

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  • Use in source · Read passage · 01_finite_core.tex, line 632

    For an orthogonal rank-one complex projector, use the scalar connection convention A=-i⟨ u,du⟩ in a local unit frame. The associated scalar curvature density is F_μν =-iTr(P[∂_μ P,∂_ν P]). On the Bloch sphere, P(θ,ϕ) = frac12(I+ n(θ,ϕ)·σ), where n=(sinθcosϕ,sinθsinϕ,cosθ). The Pauli multiplication law gives [∂_θ P,∂_ϕ P] =fraci2(∂_θ nmathbin×∂_ϕ n)·σ. Using Tr(P a·σ)= n· a therefore yields F_θϕ =frac12 n·(∂_θ nmathbin×∂_ϕ n) =frac12sinθ. The scalar sign changes if the opposite convention for A i…

    Exact mathematical passage
    
    \cF_{\mu\nu}
    =-i\Tr\left(P[\partial_\mu P,\partial_\nu P]\right).
    
\partial_\nuUse in source · 1 passage

Search aliases: ∂_ν partial nu

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  • Use in source · Read passage · 01_finite_core.tex, line 632

    For an orthogonal rank-one complex projector, use the scalar connection convention A=-i⟨ u,du⟩ in a local unit frame. The associated scalar curvature density is F_μν =-iTr(P[∂_μ P,∂_ν P]). On the Bloch sphere, P(θ,ϕ) = frac12(I+ n(θ,ϕ)·σ), where n=(sinθcosϕ,sinθsinϕ,cosθ). The Pauli multiplication law gives [∂_θ P,∂_ϕ P] =fraci2(∂_θ nmathbin×∂_ϕ n)·σ. Using Tr(P a·σ)= n· a therefore yields F_θϕ =frac12 n·(∂_θ nmathbin×∂_ϕ n) =frac12sinθ. The scalar sign changes if the opposite convention for A i…

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    \cF_{\mu\nu}
    =-i\Tr\left(P[\partial_\mu P,\partial_\nu P]\right).
    
\partial_\phiUse in source · 5 passages

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  • Use in source · monograph_atlas.tex, line 277

    LOCH PROJECTOR CALCULATIONTraditional edition: Theorem II.6.7, Corollary II.6.8. On the unit sphere, set n=(sinθcosϕ,sinθsinϕ,cosθ) and P(θ,ϕ)=frac12(I+n·σ). This is a smooth rank-one orthogonal projector. The intrinsic curvature is the endomorphism-valued two-form P( d Pwedge d P)P. With the paper's scalar convention, its component is F_θϕ=- iTr (P[∂_θ P,∂_ϕ P]) =frac12sinθ. vfigbloch_curvature headA local frame gives the same answer Away from the south pole, use u_N=(cos(θ/2),e^ iϕsin(θ/2))^T.…

    Exact mathematical passage
    
    F_{\theta\phi}=-\ii\Tr\!\left(P[\partial_\theta P,\partial_\phi P]\right)
    =\frac12\sin\theta.
    
\existsUse in source · 2 passages

Search aliases: ∃ exists

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  • Use in source · Read passage · 03_supplement_03.tex, line 18

    Several seeds: both necessity and construction. Continue under the assumption above that the number of rows is positive. For seeds C_1,…,C_k, generation means the concrete statement ∀ X∈ M_d× m( C), ∃ A_1,…,A_k∈ M_d( C): X=∑_a=1^k A_aC_a. Stack the C_a vertically into a kd× m matrix D. The source identifies the action on the stacked matrix and proves the equivalence the seeds generate Longleftrightarrow rank D=m. Thus m≤ kd is necessary. It is sufficient as well: embed the m coordinate columns i…

    Exact mathematical passage
    
    \forall X\in M_{d\times m}(\C),\quad
    \exists A_1,\ldots,A_k\in M_d(\C):\quad
    X=\sum_{a=1}^k A_aC_a.
    
\nabla^{(a)}_XUse in source · 2 passages

Search aliases: ∇^(a)_X nabla

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  • Use in source · Read passage · 03_supplement_06.tex, line 88

    The local connection and its change of coordinates. For a coordinate function u valued in E_a, define ∇^(a)_Xu=A_a(P D_M(B_a u)[X]). For every overlap point, Lean proves the operator identity ∇^(b)_X(g_abu)=g_ab∇^(a)_Xu. This is proved for arbitrary local coordinate functions. It does not assume that u was obtained from a globally smooth section or that a smooth extension has been supplied. Together with the local smoothness criterion, this closes the gluing step left open in the fifth block.

    Exact mathematical passage
    
    \nabla^{(a)}_Xu=A_a\bigl(P\,D_M(B_a u)[X]\bigr).
    
\nabla^{(b)}_XUse in source · 1 passage

Search aliases: ∇^(b)_X nabla

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  • Use in source · Read passage · 03_supplement_06.tex, line 92

    The local connection and its change of coordinates. For a coordinate function u valued in E_a, define ∇^(a)_Xu=A_a(P D_M(B_a u)[X]). For every overlap point, Lean proves the operator identity ∇^(b)_X(g_abu)=g_ab∇^(a)_Xu. This is proved for arbitrary local coordinate functions. It does not assume that u was obtained from a globally smooth section or that a smooth extension has been supplied. Together with the local smoothness criterion, this closes the gluing step left open in the fifth block.

    Exact mathematical passage
    
    \boxed{\nabla^{(b)}_X(g_{ab}u)=g_{ab}\nabla^{(a)}_Xu.}
    
\nabla_{[X,Y]}Use in source · 3 passages

Search aliases: ∇_[X,Y] nabla

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  • Use in source · Read passage · 01_finite_core.tex, line 580

    The rank of P is locally constant. On each open rank region, its ranges form a smooth vector bundle. For a smooth range section s, so that Ps=s, define ∇_Xs=P ds(X). This is a connection on smooth range sections. For smooth vector fields X,Y, its curvature satisfies (∇_X∇_Y-∇_Y∇_X-∇_[X,Y])s =P[dP(X),dP(Y)]P s. Equivalently, its endomorphism-valued curvature is F=P(dPwedge dP)P. No global frame or globally constant rank is required, and the vector fields need not commute. The geometric formalizat…

    Exact mathematical passage
    
    \boxed{
    (\nabla_X\nabla_Y-\nabla_Y\nabla_X-\nabla_{[X,Y]})s
    =P[dP(X),dP(Y)]P\,s.
    }
    
\nabla_{fX}Use in source · 1 passage

Search aliases: ∇_fX nabla

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  • Use in source · Read passage · 01_finite_core.tex, line 606

    textitConnection rules. Smoothness of P ds(X) and P^2=P show that ∇_Xs is a smooth range section. Differentiation and projection give ∇_X+Ys · =∇_Xs+∇_Ys, · ∇_fXs · =f∇_Xs, ∇_X(s+t) · =∇_Xs+∇_Xt, · ∇_X(fs) · =f∇_Xs+(Xf)s for smooth real f. The range coordinates above identify ambient smooth range sections with smooth sections of the constructed bundle.

    Exact mathematical passage
    
    \begin{aligned}
    \nabla_{X+Y}s&=\nabla_Xs+\nabla_Ys,&
    \nabla_{fX}s&=f\nabla_Xs,\\
    \nabla_X(s+t)&=\nabla_Xs+\nabla_Xt,&
    \nabla_X(fs)&=f\nabla_Xs+(Xf)s
    \end{aligned}
    
\nabla_{X+Y}Use in source · 1 passage

Search aliases: ∇_X+Y nabla

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  • Use in source · Read passage · 01_finite_core.tex, line 606

    textitConnection rules. Smoothness of P ds(X) and P^2=P show that ∇_Xs is a smooth range section. Differentiation and projection give ∇_X+Ys · =∇_Xs+∇_Ys, · ∇_fXs · =f∇_Xs, ∇_X(s+t) · =∇_Xs+∇_Xt, · ∇_X(fs) · =f∇_Xs+(Xf)s for smooth real f. The range coordinates above identify ambient smooth range sections with smooth sections of the constructed bundle.

    Exact mathematical passage
    
    \begin{aligned}
    \nabla_{X+Y}s&=\nabla_Xs+\nabla_Ys,&
    \nabla_{fX}s&=f\nabla_Xs,\\
    \nabla_X(s+t)&=\nabla_Xs+\nabla_Xt,&
    \nabla_X(fs)&=f\nabla_Xs+(Xf)s
    \end{aligned}
    
\nabla_YUse in source · 4 passages

Search aliases: ∇_Y nabla

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  • Use in source · Read passage · 01_finite_core.tex, line 580

    The rank of P is locally constant. On each open rank region, its ranges form a smooth vector bundle. For a smooth range section s, so that Ps=s, define ∇_Xs=P ds(X). This is a connection on smooth range sections. For smooth vector fields X,Y, its curvature satisfies (∇_X∇_Y-∇_Y∇_X-∇_[X,Y])s =P[dP(X),dP(Y)]P s. Equivalently, its endomorphism-valued curvature is F=P(dPwedge dP)P. No global frame or globally constant rank is required, and the vector fields need not commute. The geometric formalizat…

    Exact mathematical passage
    
    \boxed{
    (\nabla_X\nabla_Y-\nabla_Y\nabla_X-\nabla_{[X,Y]})s
    =P[dP(X),dP(Y)]P\,s.
    }
    
\prodUse in source · 2 passages

Search aliases: ∏ prod

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  • Use in source · Read passage · 03_supplement_02.tex, line 21

    For every binary address a, W_a=∏_j=0^n-1X_j^a_j=T_a, W_aψ_0=ket a. The family (W_aψ_0)_a∈ A_n is linearly independent, spans V_n, and has exactly 2^n elements. It is the standard computational basis.

    Exact mathematical passage
    
     W_a=\prod_{j=0}^{n-1}X_j^{a_j}=T_a,
     \qquad W_a\psi_0=\ket a.
    
\prod_{i\in F}Use in source · 1 passage

Search aliases: ∏_i∈ F prod in

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  • Use in source · Read passage · 03_supplement_02.tex, line 48

    Let F be an arbitrary finite set of factors and let D_i be a finite coordinate index for factor i. For matrix families A_i, define the coordinate tensor product on the product index space by T(A)(x,y)=∏_i∈ F A_i(x_i,y_i). The proof first establishes the laws for multiplication, identity, adjoints, and finite sums. These laws apply to any finite number of factors with the stated finite coordinate sets.

    Exact mathematical passage
    
     \mathsf T(A)(x,y)=\prod_{i\in F} A_i(x_i,y_i).
    
\prod_{j=0}^{n-1}Use in source · 1 passage

Search aliases: ∏_j=0^n-1 prod

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  • Use in source · Read passage · 03_supplement_02.tex, line 21

    For every binary address a, W_a=∏_j=0^n-1X_j^a_j=T_a, W_aψ_0=ket a. The family (W_aψ_0)_a∈ A_n is linearly independent, spans V_n, and has exactly 2^n elements. It is the standard computational basis.

    Exact mathematical passage
    
     W_a=\prod_{j=0}^{n-1}X_j^{a_j}=T_a,
     \qquad W_a\psi_0=\ket a.
    
\sum_{a,b}Use in source · 5 passages

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  • Use in source · monograph_atlas.tex, line 431

    nnegative entries and column sums one. Conjugate by the unitary Z. The spectrum and positivity of the quadratic form are preserved, but both off-diagonal entries become -1/4. Thus positivity as an operator is not entrywise positivity and does not by itself give a Markov interpretation. headA useful finite positive kernel For this nonnegative H, vectors u_a and times t_a≥0 satisfy ∑_a,b⟨ u_a,e^-(t_a+t_b)Hu_b⟩ = ∑_a e^-t_aHu_a ^2≥0. The factorization makes positivity transparent. It remains a fini…

    Exact mathematical passage
    
    \sum_{a,b}\langle u_a,e^{-(t_a+t_b)H}u_b\rangle
    =\left\|\sum_a e^{-t_aH}u_a\right\|^2\ge0.
    
\sum_{a,b,c}Use in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 136

    le vector occupies both parity packets. The final vector occupies only the even packet. vfigbell_circuit headHow the exact path expansion works Insert P_rm even+P_rm odd=I between the two gates. Each summand records a particular intermediate packet, while the boundary projectors select its input and output packets. Summing all terms recovers the original 4×4 circuit matrix: ∑_a,b,cP_b CNOT P_a (H_rm Had⊗ I)P_c =CNOT(H_rm Had⊗ I). This expansion is an identity even though the intermediate parity …

    Exact mathematical passage
    
    \sum_{a,b,c}P_b\,\mathrm{CNOT}\,P_a
    (H_{\rm Had}\otimes I)P_c
    =\mathrm{CNOT}(H_{\rm Had}\otimes I).
    
\sum_{a,b,c,d}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 1051

    [Exact channel block calculus] Every linear map has the exact reconstruction Φ=∑_a,b,c,dΦ_cd,ab. If Ψ:End( H_Y)→End( H_Z), then (ΨΦ)_ef,ab = ∑_c,d Ψ_ef,cdΦ_cd,ab.

    Exact mathematical passage
    
    \Phi=\sum_{a,b,c,d}\Phi_{cd,ab}.
    
\sum_{a:Z_{L,a}(t)>0}Use in source · 1 passage

Search aliases: ∑_a:Z_L,a(t)>0 sum

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  • Use in source · Read passage · 02_strengthened.tex, line 1999

    [Heat packet decomposition] If [L,P_a]=0 for every packet, then Z_L(t)=∑_aZ_L,a(t), Z_L,a(t)=Tr(P_a e^-tL). The global spectral dimension is the average of the packet dimensions weighted by their heat traces: d_L(t) = ∑_a:Z_L,a(t)>0 fracZ_L,a(t)Z_L(t) d_L,a(t), where d_L,a(t) =2t fracTr(P_aL e^-tL)Z_L,a(t) for nonempty packet heat traces.

    Exact mathematical passage
    
    d_L(t)
    =
    \sum_{a:Z_{L,a}(t)>0}
    \frac{Z_{L,a}(t)}{Z_L(t)}
     d_{L,a}(t),
    
\sum_{a=0}^1Use in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 556

    vpage30Rotate whole packets by a polar factorAN EXACT LOCAL CHART AND ITS FAILURETraditional edition: Theorem II.6.5, Theorem II.6.6. On HH= C^2, put P_0=diag(1,0), P_1=I-P_0, and R=mat3/5 · -4/5 4/5 · 3/5, Q_a=RP_aR^*, S=∑_a=0^1Q_aP_a=frac35R. The exact Gram matrices give (S-I)^*(S-I)=frac1625I, S^*S=frac925I, normS-I=frac45<1. Consequently the unitary polar factor is S(S^*S)^-1/2=R, and Q_aR=RP_a for both complete packets. xfigpolar headThe norm condition selects a chart If the target rank-one…

    Exact mathematical passage
    
    R=\mat{3/5&-4/5\\4/5&3/5},\qquad Q_a=RP_aR^*,
    \qquad S=\sum_{a=0}^1Q_aP_a=\frac35R.
    
\sum_{a=1}^kUse in source · 1 passage

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  • Use in source · Read passage · 03_supplement_03.tex, line 18

    Several seeds: both necessity and construction. Continue under the assumption above that the number of rows is positive. For seeds C_1,…,C_k, generation means the concrete statement ∀ X∈ M_d× m( C), ∃ A_1,…,A_k∈ M_d( C): X=∑_a=1^k A_aC_a. Stack the C_a vertically into a kd× m matrix D. The source identifies the action on the stacked matrix and proves the equivalence the seeds generate Longleftrightarrow rank D=m. Thus m≤ kd is necessary. It is sufficient as well: embed the m coordinate columns i…

    Exact mathematical passage
    
    \forall X\in M_{d\times m}(\C),\quad
    \exists A_1,\ldots,A_k\in M_d(\C):\quad
    X=\sum_{a=1}^k A_aC_a.
    
\sum_{a=1}^{s}Use in source · 1 passage

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  • Use in source · Read passage · 03_supplement_03.tex, line 53

    An independent definition of Schmidt rank. The source defines Schmidt rank as the least number of summands that are product vectors. A decomposition of length s is the concrete equality C_ij=∑_a=1^su_a(i)v_a(j). It factors C=UV through an s-dimensional intermediate space, so rank C≤ s. Conversely, choose a basis of the row space of C. Expanding each row in this basis constructs a decomposition with exactly rank C product terms. Thus r(ψ)=rank C. The definition uses a least natural number, and th…

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    C_{ij}=\sum_{a=1}^{s}u_a(i)v_a(j).
    
\sum_{a_1,\ldots,a_{m-1}}Use in source · 2 passages

Search aliases: ∑_a_1,…,a_m-1 sum ldots

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  • Use in source · Read passage · 02_strengthened.tex, line 390

    [Exact circuit path expansion] For source packet a_0 and target packet a_m, P_a_mUP_a_0 = ∑_a_1,…,a_m-1 P_a_mU_mP_a_m-1 ⋯ P_a_1U_1P_a_0. Summing over a_0 and a_m reconstructs U.

    Exact mathematical passage
    
    P_{a_m}UP_{a_0}
    =
    \sum_{a_1,\ldots,a_{m-1}}
    P_{a_m}U_mP_{a_{m-1}}
    \cdots
    P_{a_1}U_1P_{a_0}.
    
\sum_{a\in I}Use in source · 2 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 6

    The elementary coordinate object is a complete family of orthogonal projectors P_aP_b=δ_abP_a, ∑_a∈ IP_a=I. Every vector has packet coordinates P_aψ. Every operator has transfer blocks A_ba=P_bAP_a. These identities are simple. Their value appears when the same coordinates are used across representation theory, circuits, channels, error correction, effective dynamics, and geometric limits.

    Exact mathematical passage
    
    P_aP_b=\delta_{ab}P_a,
    \qquad
    \sum_{a\in I}P_a=I.
    
\sum_bUse in source · 6 passages

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  • Use in source · monograph_atlas.tex, line 159

    The packetwise unitarity identity is likewise an operator identity, including the off-diagonal cancellations: ∑_b U_ba^*U_bc=δ_acP_a, U_ba=P_bUP_a. It cannot be replaced by the assertion that every path individually has unit norm. The exact checks verify all four choices of a,c for the two rank-one packets, as well as the two path products leading to the opposite output.

    Exact mathematical passage
    
    \sum_b U_{ba}^*U_{bc}=\delta_{ac}P_a,
    \qquad U_{ba}=P_bUP_a.
    
\sum_{b,a}Use in source · 1 passage

Search aliases: ∑_b,a sum

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  • Use in source · Read passage · 03_supplement_01.tex, line 12

    0, · a≠ b, ∑_a∈ IP_a=1. Adjoint conditions are added when needed. For an operator U, define the transfer corner U_ba=P_bUP_a. The target index comes first. Completeness and distributivity give ∑_b,aU_ba=U, (UV)_ba=∑_c U_bcV_ca. The second identity uses P_c^2=P_c when adjacent transfer corners are multiplied.

    Exact mathematical passage
    
    \sum_{b,a}U_{ba}=U,\qquad
    (UV)_{ba}=\sum_c U_{bc}V_{ca}.
    
\sum_CUse in source · 1 passage

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  • Use in source · Read passage · 01_finite_core.tex, line 1199

    At one finite level, let widehat C_A be a finite family of matrix constraints, with fixed scalar structure coefficients, and let Π^phys be the orthogonal projector onto their exact common kernel. If the classical constraint algebra has structure coefficients f_AB^ C, define the anomaly operator A_AB = [widehat C_A,widehat C_B] -i∑_C f_AB^ Cwidehat C_C. Its physical packet is Π^phys A_ABΠ^phys. In this exact finite setting, widehat C_CΠ^phys=0 for every C. Associativity gives A_ABΠ^phys=0, Π^phys…

    Exact mathematical passage
    
    \boxed{
    \mathfrak A_{AB}
    =
    [\widehat C_A,\widehat C_B]
    -i\sum_C f_{AB}^{\ \ C}\widehat C_C.
    }
    
\sum_{c,d}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 1055

    [Exact channel block calculus] Every linear map has the exact reconstruction Φ=∑_a,b,c,dΦ_cd,ab. If Ψ:End( H_Y)→End( H_Z), then (ΨΦ)_ef,ab = ∑_c,d Ψ_ef,cdΦ_cd,ab.

    Exact mathematical passage
    
    (\Psi\Phi)_{ef,ab}
    =
    \sum_{c,d}
    \Psi_{ef,cd}\Phi_{cd,ab}.
    
\sum_{g\in G}Use in source · 2 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 207

    [Finite group isotypic projectors] The operators P_λ = fracd_λabsG ∑_g∈ G overlineχ_λ(g)U(g) are orthogonal projectors. They satisfy P_λ P_μ=δ_λμP_λ, ∑_λ∈widehat GP_λ=I_ H. The range of P_λ is the λ isotypic component of H.

    Exact mathematical passage
    
    P_\lambda
    =
    \frac{d_\lambda}{\abs{G}}
    \sum_{g\in G}
    \overline{\chi_\lambda(g)}U(g)
    
\sum_{g\in S_3}Use in source · 1 passage

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  • Use in source · monograph_atlas.tex, line 534

    , not unproved continuum claims or a new theorem count. vpage29Nonabelian packets carry multiplicityA SIX-DIMENSIONAL REGULAR REPRESENTATIONTraditional edition: Theorem II.3.1, Theorem II.3.2. Let HH= C[S_3] have the six orthonormal basis vectors ket g, with left action U(h)ket g=kethg. The irreducible characters on the identity, transposition, and three-cycle classes are c|rrr|r · e · (12) · (123) · d_λ trivial · 1 · 1 · 1 · 1 sign · 1 · -1 · 1 · 1 standard · 2 · 0 · -1 · 2 P_λ=fracd_λ6∑_g∈ S_3…

    Exact mathematical passage
    
    \begin{array}{c|rrr|r}
     & e & (12)&(123)&d_\lambda\\\hline
    \text{trivial}&1&1&1&1\\
    \text{sign}&1&-1&1&1\\
    \text{standard}&2&0&-1&2
    \end{array}
    \qquad
    P_\lambda=\frac{d_\lambda}{6}\sum_{g\in S_3}\chi_\lambda(g^{-1})U(g).
    
\sum_{i,j}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 1077

    [Finite Kraus and Choi criteria] A linear map Φ:M_n( C)→ M_m( C) is completely positive exactly when it has a Kraus representation Φ(X)=∑_rK_rXK_r^*. It is trace preserving exactly when ∑_rK_r^*K_r=I. Equivalently, its Choi matrix J(Φ) = ∑_i,jΦ(ketibraj)⊗ketibraj is positive, and trace preservation is Tr_rm outJ(Φ)=I_rm in.

    Exact mathematical passage
    
    J(\Phi)
    =
    \sum_{i,j}\Phi(\ket{i}\bra{j})\otimes\ket{i}\bra{j}
    
\sum_{i=1}^{d_\lambda}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 259

    x an irreducible unitary representation π_λ:G→ U(d_λ) and an orthonormal basis of its representation space. Define E_ij^λ = fracd_λabsG ∑_g∈ G [π_λ(g^-1)]_jiU(g). Then E_ij^λE_kℓ^μ = δ_λμδ_jkE_iℓ^λ, (E_ij^λ)^*=E_ji^λ, and P_λ=∑_i=1^d_λE_ii^λ.

    Exact mathematical passage
    
    P_\lambda=\sum_{i=1}^{d_\lambda}E_{ii}^{\lambda}.
    
\sum_jUse in source · 20 passages

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  • Use in source · monograph_atlas.tex, line 102

    Multiplying the actual projectors gives P_jP_k=0 for j≠ k, P_j^2=P_j, and ∑_jP_j=I. In particular, the complete packet tuple (P_jψ)_j retains the original vector exactly. Recording only the four packet norms is a different operation and can discard phase information between packets.

    Exact mathematical passage
    \sum_jP_j=I
\sum_{j,k}Use in source · 5 passages

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  • Use in source · monograph_atlas.tex, line 688

    ts memory kernel is K(t)=frac925e^- i t+frac1625e^-2 i t, K(0)=1. Each oscillatory coefficient is positive although K(t) need not be real or pointwise nonnegative. At t=π/2, it equals -16/25-9 i/25. xfigmemory_positive headPositive definite means a matrix test at arbitrary times For retained scalars v_j and real times t_j, the structural identity is ∑_j,koverline v_jK(t_j-t_k)v_k = ∑_k e^ i t_kDB^*v_k ^2≥0. The exact worked check specializes to t=(0,π/2,π) and v=(1,2,-1). Its phases lie in QQ( i…

    Exact mathematical passage
    
    \sum_{j,k}\overline v_jK(t_j-t_k)v_k
    =\left\|\sum_k e^{\ii t_kD}B^*v_k\right\|^2\geq0.
    
\sum_{j,k=1}^{m}Use in source · 1 passage

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  • Use in source · Read passage · 02_strengthened.tex, line 1714

    [Positive definite quantum memory] The kernel K(t-s) is positive definite. For times t_1,…,t_m and retained vectors v_1,…,v_m, ∑_j,k=1^m ipv_jK(t_j-t_k)v_k ≥0.

    Exact mathematical passage
    
    \sum_{j,k=1}^{m}
    \ip{v_j}{K(t_j-t_k)v_k}
    \geq0.
    
\sum_{j=0}^{N-1}Use in source · 1 passage

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  • Use in source · Read passage · 01_finite_core.tex, line 206

    [Cyclic quantum projectors] The operators P_j = frac1N∑_r=0^N-1ω^-jrS^r, 0≤ j<N, are self-adjoint, pairwise orthogonal projectors satisfying P_jP_k=δ_jkP_j, ∑_j=0^N-1P_j=I, SP_j=ω^jP_j.

    Exact mathematical passage
    
    P_jP_k=\delta_{jk}P_j,
    \qquad
    \sum_{j=0}^{N-1}P_j=I,
    \qquad
    SP_j=\omega^jP_j.
    
\sum_{j=1}^{d}Use in source · 2 passages

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  • Use in source · Read passage · 02_strengthened.tex, line 2022

    Let N≥2 and let Λ_N=( Z/N Z)^d be the unit flat torus grid with spacing 1/N. The standard periodic difference Laplacian has eigenvalues λ_N(k) = 4N^2 ∑_j=1^d sin^2(fracπ k_jN), where k runs through centered residue representatives. This is the standard periodic finite difference Laplacian [source reference].

    Exact mathematical passage
    
    \lambda_N(k)
    =
    4N^2
    \sum_{j=1}^{d}
    \sin^2\left(\frac{\pi k_j}{N}\right),
    
\sum_{j_1+\cdots+j_m=r}Use in source · 1 passage

Search aliases: ∑_j_1+⋯+j_m=r sum cdots

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  • Use in source · Read passage · 02_strengthened.tex, line 351

    [Tensor charge refinement] For r∈ Z/N Z, define P_r^rm total = ∑_j_1+⋯+j_m=r P_j_1^(1)⊗⋯⊗ P_j_m^(m). Then the P_r^rm total form a complete orthogonal packet system. Every total charge packet is the exact sum of its fine tensor descendants.

    Exact mathematical passage
    
    P_r^{\rm total}
    =
    \sum_{j_1+\cdots+j_m=r}
    P_{j_1}^{(1)}\otimes\cdots\otimes P_{j_m}^{(m)}.
    
\sum_{j_1+\cdots+j_m\equiv r\pmod N}Use in source · 1 passage

Search aliases: ∑_j_1+⋯+j_m≡ rpmod N sum cdots equiv pmod

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  • Use in source · Read passage · 01_finite_core.tex, line 247

    [Tensor/polyphase refinement] For each residue r∈ Z/N Z, define P_r^coarse = ∑_j_1+⋯+j_m≡ rpmod N P^(1)_j_1⊗⋯⊗ P^(m)_j_m. Then the P_r^coarse are complete orthogonal projectors, and every coarse packet is the exact sum of its fine descendants.

    Exact mathematical passage
    
    \boxed{
    P_r^{\mathrm{coarse}}
    =
    \sum_{j_1+\cdots+j_m\equiv r\pmod N}
    P^{(1)}_{j_1}\otimes\cdots\otimes P^{(m)}_{j_m}.
    }
    
\sum_kUse in source · 5 passages

Search aliases: ∑_k sum

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  • Use in source · monograph_atlas.tex, line 688

    ts memory kernel is K(t)=frac925e^- i t+frac1625e^-2 i t, K(0)=1. Each oscillatory coefficient is positive although K(t) need not be real or pointwise nonnegative. At t=π/2, it equals -16/25-9 i/25. xfigmemory_positive headPositive definite means a matrix test at arbitrary times For retained scalars v_j and real times t_j, the structural identity is ∑_j,koverline v_jK(t_j-t_k)v_k = ∑_k e^ i t_kDB^*v_k ^2≥0. The exact worked check specializes to t=(0,π/2,π) and v=(1,2,-1). Its phases lie in QQ( i…

    Exact mathematical passage
    
    \sum_{j,k}\overline v_jK(t_j-t_k)v_k
    =\left\|\sum_k e^{\ii t_kD}B^*v_k\right\|^2\geq0.
    
\sum_{k=1}^{m}Use in source · 1 passage

Search aliases: ∑_k=1^m sum

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  • Use in source · Read passage · 02_strengthened.tex, line 1723

    Set w=∑_k=1^m e^ i t_kDB^*v_k. Then norm w^2 = ∑_j,k ipB^*v_j e^- i(t_j-t_k)DB^*v_k = ∑_j,k ipv_jK(t_j-t_k)v_k.

    Exact mathematical passage
    
    w=\sum_{k=1}^{m}\e^{\ii t_kD}B^*v_k.
    
\sum_{k\in\ZZ^d}Use in source · 3 passages

Search aliases: ∑_k∈ZZ^d ∑_k∈ Z^d sum in ZZ sum in mathbb

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  • Use in source · Read passage · 02_strengthened.tex, line 2061

    [Fixed time heat trace convergence] For every t>0, ∑_k∈Λ_N^* e^-tλ_N(k) ⟶ ∑_k∈ Z^d e^-4π^2tabsk^2 as N→∞. The first spectral moments also converge: ∑_k∈Λ_N^* λ_N(k) e^-tλ_N(k) ⟶ ∑_k∈ Z^d 4π^2absk^2 e^-4π^2tabsk^2. Consequently, the discrete spectral dimensions converge to the continuum torus spectral dimension at every fixed positive time.

    Exact mathematical passage
    
    \sum_{k\in\Lambda_N^*}
    \e^{-t\lambda_N(k)}
    \longrightarrow
    \sum_{k\in\ZZ^d}
    \e^{-4\pi^2t\abs{k}^2}
    
\sum_{k\in\Lambda_N^*}Use in source · 2 passages

Search aliases: ∑_k∈Λ_N^* sum in Lambda

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  • Use in source · Read passage · 02_strengthened.tex, line 2061

    [Fixed time heat trace convergence] For every t>0, ∑_k∈Λ_N^* e^-tλ_N(k) ⟶ ∑_k∈ Z^d e^-4π^2tabsk^2 as N→∞. The first spectral moments also converge: ∑_k∈Λ_N^* λ_N(k) e^-tλ_N(k) ⟶ ∑_k∈ Z^d 4π^2absk^2 e^-4π^2tabsk^2. Consequently, the discrete spectral dimensions converge to the continuum torus spectral dimension at every fixed positive time.

    Exact mathematical passage
    
    \sum_{k\in\Lambda_N^*}
    \e^{-t\lambda_N(k)}
    \longrightarrow
    \sum_{k\in\ZZ^d}
    \e^{-4\pi^2t\abs{k}^2}
    
\sum_{n=0}^{\infty}Use in source · 4 passages

Search aliases: ∑_n=0^∞ sum infty

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  • Use in source · monograph_atlas.tex, line 670

    |=frac2556, frac2gδ|B-widetilde B| +fracg^2δ^2|D-widetilde D|=frac2132. The theorem bounds the difference using a common spectral gap. Applying the bound uniformly to a refinement family requires uniform spectral separation and control of the couplings. headA series near zero energy and its exact remainder At z=1/2, |z| |D^-1|=1/4<1, so Σ(z)=-∑_n=0^∞fracz^n2^n+1. After the first four terms, the exact remainder has magnitude 1/384. The geometric series controls the infinite tail. The retained che…

    Exact mathematical passage
    
    \Sigma(z)=-\sum_{n=0}^{\infty}\frac{z^n}{2^{n+1}}.
    
\sum_{n\in\ZZ^d}Use in source · 1 passage

Search aliases: ∑_n∈ZZ^d ∑_n∈ Z^d sum in ZZ sum in mathbb

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  • Use in source · Read passage · 02_strengthened.tex, line 2107

    [Theta transformation] The continuum flat torus heat trace satisfies Z_d(t) = ∑_k∈ Z^d e^-4π^2tabsk^2 = (4π t)^-d/2 ∑_n∈ Z^d e^-absn^2/(4t). This is the Poisson summation formula for a Gaussian.

    Exact mathematical passage
    
    Z_d(t)
    =
    \sum_{k\in\ZZ^d}\e^{-4\pi^2t\abs{k}^2}
    =
    (4\pi t)^{-d/2}
    \sum_{n\in\ZZ^d}\e^{-\abs{n}^2/(4t)}.
    
\sum_{n\neq0}Use in source · 1 passage

Search aliases: ∑_n≠0 sum neq

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  • Use in source · Read passage · 02_strengthened.tex, line 2140

    By [source reference], Z_d(t) =(4π t)^-d/2(1+R(t)), where R(t)=∑_n≠0 e^-absn^2/(4t) =O( e^-1/(4t)). Differentiation gives tR'(t)=O(t^-1 e^-1/(4t)). Substituting this estimate into the logarithmic derivative gives the stated small time expansion.

    Exact mathematical passage
    
    R(t)=\sum_{n\neq0}\e^{-\abs{n}^2/(4t)}
    =O\bigl(\e^{-1/(4t)}\bigr).
    
\sum_qUse in source · 1 passage

Search aliases: ∑_q sum

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  • Use in source · Read passage · 02_strengthened.tex, line 485

    [Charge pruning of circuit paths] Suppose every gate has a finite charge decomposition U_r=∑_qU_r^(q), SU_r^(q)S^*=ω^qU_r^(q). A term with gate charges q_1,…,q_m can contribute from source charge a_0 only to target charge a_m=a_0+q_1+⋯+q_m. Every packet path violating one of the intermediate charge updates vanishes.

    Exact mathematical passage
    
    U_r=\sum_qU_r^{(q)},
    \qquad
    SU_r^{(q)}S^*=\omega^qU_r^{(q)}.
    
\sum_rUse in source · 12 passages

Search aliases: ∑_r sum

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  • Use in source · Read passage · 01_finite_core.tex, line 855

    _rδ_rsP. If λ_r=0, F_r^*F_r=0 forces F_r=0. For positive eigenvalues only, set V_r=F_r/sqrtλ_r. These satisfy V_rP=V_r, V_r^*V_s=δ_rsP. Let S=∑_λ_r>0V_rV_r^*. Orthogonality makes S an orthogonal projector. Use the recovery branches K_r=V_r^*, K_unused=I-S. They are complete on the whole ambient space because ∑_rK_r^*K_r+K_unused^*K_unused =S+(I-S)^2=I. The inverse unitary change of coordinates reconstructs each E_aP from the F_r. Every recovery branch of a coherent combination is therefore scala…

    Exact mathematical passage
    
    \sum_rK_r^*K_r+K_{\mathrm{unused}}^*K_{\mathrm{unused}}
    =S+(I-S)^2=I.
    
\sum_{r}Use in source · 1 passage

Search aliases: ∑_r sum

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  • Use in source · Read passage · 02_strengthened.tex, line 1740

    [Finite oscillatory memory expansion] If D=∑_rE_rQ_r is the spectral decomposition of the hidden Hamiltonian, then K(t)=∑_r e^- i tE_rBQ_rB^*. Every coefficient BQ_rB^* is positive semidefinite.

    Exact mathematical passage
    
    D=\sum_{r}E_rQ_r
    
\sum_{r,a}Use in source · 1 passage

Search aliases: ∑_r,a sum

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  • Use in source · Read passage · 03_supplement_05.tex, line 91

    Deriving the Gram matrix from recovery Suppose a finite recovery that preserves trace corrects every operator supported on the code. To derive the Knill--Laflamme condition without assuming a syndrome decomposition, the proof expands the composite channel into the finite Kraus family A_ra=R_rE_aP. For every ambient matrix ρ, correction on the code implies ∑_r,a A_raρ A_ra^*=Pρ P. This equality on all matrices follows by applying correction to the sandwich supported on the code, Pρ P, using the p…

    Exact mathematical passage
    
    \sum_{r,a} A_{ra}\rho A_{ra}^*=P\rho P.
    
\sum_{r=0}^3Use in source · 1 passage

Search aliases: ∑_r=0^3 sum

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  • Use in source · monograph_atlas.tex, line 93

    vpage6Four phases resolve a cyclic shiftCHARACTER PROJECTORS YOU CAN MULTIPLYTraditional edition: Corollary II.3.3. On four sites, let Sket k=ketk+1bmod4 and let ω= i. The character projectors are the exact matrices P_j=frac14∑_r=0^3 i^-jrS^r, v_j(k)=frac12 i^-jk, P_j=v_jv_j^*. All entries belong to the Gaussian rationals. Thus no approximation to a root of unity is needed in this model. vfigcyclic_four headReading the columns Each column v_j is a normalized wave around the four sites. Advancing…

    Exact mathematical passage
    
    P_j=\frac14\sum_{r=0}^3\ii^{-jr}S^r,
    \qquad v_j(k)=\frac12\ii^{-jk},\qquad P_j=v_jv_j^*.
    
\sum_{r=0}^{N-1}Use in source · 5 passages

Search aliases: ∑_r=0^N-1 sum

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  • Use in source · Read passage · 01_finite_core.tex, line 196

    [Cyclic quantum projectors] The operators P_j = frac1N∑_r=0^N-1ω^-jrS^r, 0≤ j<N, are self-adjoint, pairwise orthogonal projectors satisfying P_jP_k=δ_jkP_j, ∑_j=0^N-1P_j=I, SP_j=ω^jP_j.

    Exact mathematical passage
    
    \boxed{
    P_j
    =
    \frac1N\sum_{r=0}^{N-1}\omega^{-jr}S^r,
    \qquad
    0\le j<N,
    }
    
\sum_{r\in\mathbb Z/N\mathbb Z}Use in source · 1 passage

Search aliases: ∑_r∈ Z/N Z sum in mathbb mathbb

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  • Use in source · Read passage · 03_supplement_03.tex, line 105

    Exact coefficient formula. The packet definition is a finite sum over residue classes: P_j=frac1N∑_r∈ Z/N Zχ(-rj)ρ(r). The source proves χ(-rj)=(ω^val(r)val(j))^-1, so this is precisely the manuscript's N-term Fourier projector formula, with canonical representatives.

    Exact mathematical passage
    
    P_j=\frac1N\sum_{r\in\mathbb Z/N\mathbb Z}\chi(-rj)\rho(r).
    
\sum_{\substack{\gamma,\gamma'\in\Gamma_b\\ \gamma<\gamma'}}Use in source · 1 passage

Search aliases: ∑_substackγ,γ'∈Γ_b γ<γ' sum substack gamma gamma in Gamma gamma gamma

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  • Use in source · Read passage · 02_strengthened.tex, line 457

    [Path interference formula] Fix a source vector ψ∈ P_a_0 H and a target packet b. Let Γ_b be the set of packet paths from a_0 to b, and set η_γ=U_γψ. Choose any total order on this finite path set. Then normP_bUψ^2 = ∑_γ∈Γ_bnormη_γ^2 + 2Re ∑_substackγ,γ'∈Γ_b γ<γ' ipη_γη_γ'. Consequently, normP_bUψ ≤ ∑_γ∈Γ_bnormη_γ. If the path outputs are pairwise orthogonal, the target probability is the sum of the path probabilities.

    Exact mathematical passage
    
    \norm{P_bU\psi}^2
    =
    \sum_{\gamma\in\Gamma_b}\norm{\eta_\gamma}^2
    +
    2\operatorname{Re}
    \sum_{\substack{\gamma,\gamma'\in\Gamma_b\\ \gamma<\gamma'}}
    \ip{\eta_\gamma}{\eta_{\gamma'}}.
    
\sum_{\alpha_1,\ldots,\alpha_{m-1}}Use in source · 1 passage

Search aliases: ∑_α_1,…,α_m-1 sum alpha ldots alpha

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  • Use in source · Read passage · 01_finite_core.tex, line 283

    [Exact circuit path expansion] For source packet α_0 and target packet α_m, P_α_mUP_α_0 = ∑_α_1,…,α_m-1 P_α_mU_mP_α_m-1 ⋯ P_α_1U_1P_α_0. Summing over the source and target packets reconstructs the complete circuit operator.

    Exact mathematical passage
    
    \boxed{
    P_{\alpha_m}UP_{\alpha_0}
    =
    \sum_{\alpha_1,\ldots,\alpha_{m-1}}
    P_{\alpha_m}U_mP_{\alpha_{m-1}}
    \cdots
    P_{\alpha_1}U_1P_{\alpha_0}.
    }
    
\sum_\betaUse in source · 2 passages

Search aliases: ∑_β sum beta

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  • Use in source · Read passage · 01_finite_core.tex, line 302

    [Packetwise unitarity conservation] If U is unitary and U_βα=P_β UP_α, then ∑_β U_βα^*U_βγ = δ_αγP_α. Similarly, ∑_α U_βαU_δα^* = δ_βδP_β.

    Exact mathematical passage
    
    \boxed{
    \sum_\beta U_{\beta\alpha}^*U_{\beta\gamma}
    =
    \delta_{\alpha\gamma}P_\alpha.
    }
    
\sum_{\beta\succ\alpha}Use in source · 1 passage

Search aliases: ∑_βsuccα sum beta succ alpha

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  • Use in source · Read passage · 01_finite_core.tex, line 1026

    A coherent refinement should satisfy C_ℓ E_ℓ=I and P_ℓ,α = C_ℓ ( ∑_βsuccαP_ℓ+1,β ) E_ℓ. For an operator D, define the refinement defect Δ_ℓ(D) =C_ℓ D_ℓ+1E_ℓ-D_ℓ. Exact resolution independence is Δ_ℓ(D)=0. When exact equality is too strong, the correct continuum problem is to prove convergence of the resolvents and uniform control of the effective self-energies.

    Exact mathematical passage
    
    \boxed{
    P_{\ell,\alpha}
    =
    C_\ell
    \left(
    \sum_{\beta\succ\alpha}P_{\ell+1,\beta}
    \right)
    E_\ell.
    }
    
\sum_{\gamma\in\Gamma_b}Use in source · 3 passages

Search aliases: ∑_γ∈Γ_b sum gamma in Gamma

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  • Use in source · Read passage · 02_strengthened.tex, line 457

    [Path interference formula] Fix a source vector ψ∈ P_a_0 H and a target packet b. Let Γ_b be the set of packet paths from a_0 to b, and set η_γ=U_γψ. Choose any total order on this finite path set. Then normP_bUψ^2 = ∑_γ∈Γ_bnormη_γ^2 + 2Re ∑_substackγ,γ'∈Γ_b γ<γ' ipη_γη_γ'. Consequently, normP_bUψ ≤ ∑_γ∈Γ_bnormη_γ. If the path outputs are pairwise orthogonal, the target probability is the sum of the path probabilities.

    Exact mathematical passage
    
    \norm{P_bU\psi}^2
    =
    \sum_{\gamma\in\Gamma_b}\norm{\eta_\gamma}^2
    +
    2\operatorname{Re}
    \sum_{\substack{\gamma,\gamma'\in\Gamma_b\\ \gamma<\gamma'}}
    \ip{\eta_\gamma}{\eta_{\gamma'}}.
    
\sum_{\lambda_j>0}Use in source · 4 passages

Search aliases: ∑_λ_j>0 sum lambda

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  • Use in source · Read passage · 02_strengthened.tex, line 1357

    [Exact recovery on the error span] Under the hypotheses of [source reference], define on the syndrome support Q=∑_λ_j>0Q_j the completely positive map R_0(X) = ∑_λ_j>0 V_j^*Q_jXQ_jV_j. It extends to a quantum channel R on End( H). If Φ(X)=∑_aE_aXE_a^* is trace preserving on code states, then RΦ(ρ)=ρ for every density matrix ρ=Pρ P.

    Exact mathematical passage
    
    Q=\sum_{\lambda_j>0}Q_j
    
\sum_{\lambda_r>0}Use in source · 1 passage

Search aliases: ∑_λ_r>0 sum lambda

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  • Use in source · Read passage · 01_finite_core.tex, line 850

    titSufficiency. Diagonalize C=Udiag(λ_r)U^* with U unitary and λ_r≥0. Define compressed transformed errors F_r=∑_aU_arE_aP. Then F_rP=F_r and F_r^*F_s=λ_rδ_rsP. If λ_r=0, F_r^*F_r=0 forces F_r=0. For positive eigenvalues only, set V_r=F_r/sqrtλ_r. These satisfy V_rP=V_r, V_r^*V_s=δ_rsP. Let S=∑_λ_r>0V_rV_r^*. Orthogonality makes S an orthogonal projector. Use the recovery branches K_r=V_r^*, K_unused=I-S. They are complete on the whole ambient space because ∑_rK_r^*K_r+K_unused^*K_unused =S+(I-S…

    Exact mathematical passage
    S=\sum_{\lambda_r>0}V_rV_r^*
\sum_{\lambda\in\widehat G}Use in source · 1 passage

Search aliases: ∑_λ∈widehat G sum lambda in widehat

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  • Use in source · Read passage · 02_strengthened.tex, line 215

    [Finite group isotypic projectors] The operators P_λ = fracd_λabsG ∑_g∈ G overlineχ_λ(g)U(g) are orthogonal projectors. They satisfy P_λ P_μ=δ_λμP_λ, ∑_λ∈widehat GP_λ=I_ H. The range of P_λ is the λ isotypic component of H.

    Exact mathematical passage
    
    P_\lambda P_\mu=\delta_{\lambda\mu}P_\lambda,
    \qquad
    \sum_{\lambda\in\widehat G}P_\lambda=I_{\Hcal}.
    
\sum_{\sum_i a_i=r}Use in source · 1 passage

Search aliases: ∑_∑_i a_i=r sum sum

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  • Use in source · Read passage · 03_supplement_02.tex, line 54

    Suppose N>0 and each factor has a complete orthogonal self-adjoint projector family (P^(i)_j)_j∈ Z/N Z. For a fine address a:F→ Z/N Z, set Q_a= T(i↦ P^(i)_a_i), C_r=∑_∑_i a_i=rQ_a.

    Exact mathematical passage
    
     Q_a=\mathsf T\bigl(i\mapsto P^{(i)}_{a_i}\bigr),
     \qquad
     C_r=\sum_{\sum_i a_i=r}Q_a.
    
\inftyUse in source · 28 passages

Search aliases: ∞ infty

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  • Use in source · monograph_atlas.tex, line 452

    τ)=frac1+2e^-2τ+e^-4τ4 =frac(1+e^-2τ)^24, d_s(τ)=-2τfracK'(τ)K(τ) =frac8τe^2τ+1. No numerical differentiation is needed for this finite example. vfigspectral_dimension headBoth ends reflect the finite size of the system As τ→0, every eigenmode contributes approximately one and the dimension diagnostic tends to zero. As τ→∞, the zero mode dominates, so it again tends to zero. A finite spectrum cannot sustain a nonzero plateau at all scales.

    Exact mathematical passage
    \tau\to\infty
\capUse in source · 1 passage

Search aliases: ∩ cap

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  • Use in source · Read passage · 03_supplement_06.tex, line 49

    Smooth overlap maps and rank. The coordinate transition is g_ab(x)=A_b(x)B_a(x). It is smooth on U_a∩ U_b, agrees with the actual change between local homeomorphisms, and satisfies g_aa=I, g_bcg_ab=g_ac. A continuous linear equivalence between E_a and E_x also gives local constancy of fiber dimension. No single constant rank across disconnected components is assumed.

    Exact mathematical passage
    U_a\cap U_b
\int_0^{2\pi}Use in source · 1 passage

Search aliases: ∫_0^2π int pi

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  • Use in source · Read passage · 02_strengthened.tex, line 910

    [Bloch sphere curvature] Let P(θ,ϕ) = frac12(I+ n(θ,ϕ)·σ), where n=(sinθcosϕ,sinθsinϕ,cosθ). With the convention F_θϕ =- iTr(P[∂_θ P,∂_ϕ P]), one has F_θϕ=frac12sinθ and frac12π ∫_0^2π∫_0^π F_θϕ dθ dϕ =1.

    Exact mathematical passage
    
    \frac1{2\pi}
    \int_0^{2\pi}\int_0^\pi
    \Fcal_{\theta\phi}\dd\theta\dd\phi
    =1.
    
\int_0^\piUse in source · 1 passage

Search aliases: ∫_0^π int pi

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  • Use in source · Read passage · 02_strengthened.tex, line 910

    [Bloch sphere curvature] Let P(θ,ϕ) = frac12(I+ n(θ,ϕ)·σ), where n=(sinθcosϕ,sinθsinϕ,cosθ). With the convention F_θϕ =- iTr(P[∂_θ P,∂_ϕ P]), one has F_θϕ=frac12sinθ and frac12π ∫_0^2π∫_0^π F_θϕ dθ dϕ =1.

    Exact mathematical passage
    
    \frac1{2\pi}
    \int_0^{2\pi}\int_0^\pi
    \Fcal_{\theta\phi}\dd\theta\dd\phi
    =1.
    
\int_0^\inftyUse in source · 1 passage

Search aliases: ∫_0^∞ int infty

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  • Use in source · Read passage · 02_strengthened.tex, line 1692

    · - i∫_0^tK(t-s)x(s) d s, where K(t)=B e^- i tDB^*. For Res>0, ∫_0^∞ e^-stK(t) d t = B(s+ i D)^-1B^*.

    Exact mathematical passage
    
    \int_0^\infty\e^{-st}K(t)\dd t
    =
    B(s+\ii D)^{-1}B^*.
    
\simeqUse in source · 4 passages

Search aliases: ≃ simeq

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  • Use in source · Read passage · 03_supplement_03.tex, line 9

    A matrix X belongs to O(C) exactly when each of its rows belongs to Row(C). One direction follows by expanding AC. For the converse, choose the coefficients producing each row separately and place them in the corresponding row of A. An explicit linear equivalence therefore gives O(C)≃ Row(C)^d, dim_ C O(C)=d rank C. If d>0, equality with the full d× m coefficient space is equivalent to rank C=m. Consequently a cyclic seed requires m≤ d. The assumption that there is at least one row is essential …

    Exact mathematical passage
    
    \mathcal O(C)\simeq \operatorname{Row}(C)^d,
    \qquad
    \boxed{\dim_\C\mathcal O(C)=d\,\rank C.}
    
\congUse in source · 7 passages

Search aliases: ≅ cong

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  • Use in source · Read passage · 01_finite_core.tex, line 79

    Let a finite-dimensional unital *-subalgebra of operators act in its standard multiplicity form A ≅ ⊕_i=1^r (M_d_i( C)⊗ I_m_i) on H ≅ ⊕_i=1^r ( C^d_i⊗ C^m_i). Here every d_i is a positive integer and every multiplicity m_i is a nonnegative integer. An empty block family represents the zero space and has seed rank zero. The maximum over an empty block family is also assigned the value zero. A vector ψ_i∈ C^d_i⊗ C^m_i is identified with a d_i× m_i coefficient matrix C_i.

    Exact mathematical passage
    
    \cA
    \cong
    \bigoplus_{i=1}^r
    \left(M_{d_i}(\bbC)\otimes I_{m_i}\right)
    
\neUse in source · 20 passages

Search aliases: ≠ ne

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  • Use in source · monograph_atlas.tex, line 102

    Multiplying the actual projectors gives P_jP_k=0 for j≠ k, P_j^2=P_j, and ∑_jP_j=I. In particular, the complete packet tuple (P_jψ)_j retains the original vector exactly. Recording only the four packet norms is a different operation and can discard phase information between packets.

    Exact mathematical passage
    j\ne k
\neqUse in source · 3 passages

Search aliases: ≠ neq

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  • Use in source · Read passage · 02_strengthened.tex, line 524

    [Exact invariant packets] The following conditions are equivalent: item The Hamiltonian commutes with each projector: [H,P_a]=0 for every a. item Transfer blocks between distinct packets vanish: P_bHP_a=0 whenever a≠ b. item Every packet P_a H is invariant under e^- i tH for every real t. When they hold, H=∑_aP_aHP_a and e^- i tH=∑_aP_a e^- i tHP_a.

    Exact mathematical passage
    a\neq b
\equivUse in source · 1 passage

Search aliases: ≡ equiv

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  • Use in source · Read passage · 01_finite_core.tex, line 247

    [Tensor/polyphase refinement] For each residue r∈ Z/N Z, define P_r^coarse = ∑_j_1+⋯+j_m≡ rpmod N P^(1)_j_1⊗⋯⊗ P^(m)_j_m. Then the P_r^coarse are complete orthogonal projectors, and every coarse packet is the exact sum of its fine descendants.

    Exact mathematical passage
    
    \boxed{
    P_r^{\mathrm{coarse}}
    =
    \sum_{j_1+\cdots+j_m\equiv r\pmod N}
    P^{(1)}_{j_1}\otimes\cdots\otimes P^{(m)}_{j_m}.
    }
    
\leqUse in source · 36 passages

Search aliases: ≤ leq

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  • Use in source · monograph_atlas.tex, line 632

    On a two-dimensional code, consider the overlap compression A=PE_a^*E_bP=diag(11/10,9/10). For instance, within the code take E_a=I and E_b=A. This declares an error family, not by itself a normalized noise channel. The optimal scalar compression has inf_c∈ CnormA-cI=frac110, c=1 attains it. Indeed, for every complex c, the triangle inequality gives frac15=|frac1110-frac910| ≤|frac1110-c|+|frac910-c|. Thus the larger of the two distances is at least 1/10, while both distances equal 1/10 at c=1. …

    Exact mathematical passage
    
    \frac15=\left|\frac{11}{10}-\frac9{10}\right|
    \leq\left|\frac{11}{10}-c\right|+\left|\frac9{10}-c\right|.
    
\subsetUse in source · 1 passage

Search aliases: ⊂ subset

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  • Use in source · Read passage · 01_finite_core.tex, line 792

    Let P=P^*=P^2 project onto a code space C⊂ H, and let E_1,…,E_r be a finite family of complex error matrices. Neither a nonzero code nor channel normalization is assumed unless stated. The operators P E_a^*E_bP are the obstruction packets on the code. If they retain information about the logical state beyond one scalar multiple of P, the environment can distinguish logical states and exact correction is impossible.

    Exact mathematical passage
    \cC\subset\cH
\oplusUse in source · 7 passages

Search aliases: ⊕ oplus

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  • Use in source · monograph_atlas.tex, line 746

    vpage38Transport constraints without hiding closureTHE IMAGE OF AN ISOMETRY IS NOT THE WHOLE LEVELTraditional edition: Theorem II.12.2, Theorem II.12.5, Proposition II.12.6. On C^3= Cket0⊕ C^2, use C_a=0⊕σ_a for a=x,y,z. The common kernel is Cket0, and the full algebra closes: [C_x,C_y]=2 i C_z, [C_y,C_z]=2 i C_x, [C_z,C_x]=2 i C_y. These are uncompressed identities. They supply an actual closure test in the quotient by the constraint span, unlike the automatic compressed zero on the physical ke…

    Exact mathematical passage
    \CC^3=\CC\ket0\oplus\CC^2
\bigoplus_{i=1}^rUse in source · 2 passages

Search aliases: ⊕_i=1^r bigoplus

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  • Use in source · Read passage · 01_finite_core.tex, line 79

    Let a finite-dimensional unital *-subalgebra of operators act in its standard multiplicity form A ≅ ⊕_i=1^r (M_d_i( C)⊗ I_m_i) on H ≅ ⊕_i=1^r ( C^d_i⊗ C^m_i). Here every d_i is a positive integer and every multiplicity m_i is a nonnegative integer. An empty block family represents the zero space and has seed rank zero. The maximum over an empty block family is also assigned the value zero. A vector ψ_i∈ C^d_i⊗ C^m_i is identified with a d_i× m_i coefficient matrix C_i.

    Exact mathematical passage
    
    \cA
    \cong
    \bigoplus_{i=1}^r
    \left(M_{d_i}(\bbC)\otimes I_{m_i}\right)
    
\bigoplus_jUse in source · 1 passage

Search aliases: ⊕_j bigoplus

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  • Use in source · Read passage · 02_strengthened.tex, line 1111

    erence order projectors] For q∈ Z/N Z, define L_q(X) = frac1N ∑_r=0^N-1 ω^-qrS^rXS^-r. Then the L_q form a complete orthogonal packet system on Hilbert Schmidt operator space. Their ranges are the operators satisfying SXS^*=ω^qX. If P_j are the state charge projectors, then Ran L_q = ⊕_jP_j+qEnd( H)P_j.

    Exact mathematical passage
    
    \Ran\Lcal_q
    =
    \bigoplus_jP_{j+q}\End(\Hcal)P_j.
    
\bigoplus_{r=1}^{s}Use in source · 2 passages

Search aliases: ⊕_r=1^s bigoplus

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  • Use in source · Read passage · 02_strengthened.tex, line 104

    Let A ≅ ⊕_r=1^s (M_d_r( C)⊗ I_m_r) act on H ≅ ⊕_r=1^s ( C^d_r⊗ C^m_r). Assume d_r,m_r≥1 for each displayed block. For an empty block family, the seed rank and the displayed finite supremum are defined as zero. A vector in one block is identified with a d_r by m_r coefficient matrix.

    Exact mathematical passage
    
    \Acal
    \cong
    \bigoplus_{r=1}^{s}
    \bigl(M_{d_r}(\CC)\otimes I_{m_r}\bigr)
    
\bigoplus_\muUse in source · 1 passage

Search aliases: ⊕_μ bigoplus mu

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  • Use in source · Read passage · 02_strengthened.tex, line 225

    Complete reducibility gives a unitary decomposition H ≅ ⊕_μ∈widehat G V_μ⊗ M_μ, U(g) ≅ ⊕_μ π_μ(g)⊗ I_M_μ. On the μ summand, the displayed average is central in the irreducible representation π_μ, so it is a scalar by Schur's lemma. Taking its trace and applying character orthogonality shows that the scalar is one when μ=λ and zero otherwise. The asserted identities follow on the direct sum.

    Exact mathematical passage
    
    \Hcal
    \cong
    \bigoplus_{\mu\in\widehat G}
    V_\mu\otimes M_\mu,
    \qquad
    U(g)
    \cong
    \bigoplus_\mu
    \pi_\mu(g)\otimes I_{M_\mu}.
    
\bigoplus_{\mu\in\widehat G}Use in source · 1 passage

Search aliases: ⊕_μ∈widehat G bigoplus mu in widehat

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  • Use in source · Read passage · 02_strengthened.tex, line 225

    Complete reducibility gives a unitary decomposition H ≅ ⊕_μ∈widehat G V_μ⊗ M_μ, U(g) ≅ ⊕_μ π_μ(g)⊗ I_M_μ. On the μ summand, the displayed average is central in the irreducible representation π_μ, so it is a scalar by Schur's lemma. Taking its trace and applying character orthogonality shows that the scalar is one when μ=λ and zero otherwise. The asserted identities follow on the direct sum.

    Exact mathematical passage
    
    \Hcal
    \cong
    \bigoplus_{\mu\in\widehat G}
    V_\mu\otimes M_\mu,
    \qquad
    U(g)
    \cong
    \bigoplus_\mu
    \pi_\mu(g)\otimes I_{M_\mu}.
    
\perpUse in source · 2 passages

Search aliases: ⊥ perp

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  • Use in source · Read passage · 02_strengthened.tex, line 1385

    The map R_0 is completely positive. It is trace preserving on operators supported in Q H because Tr(V_j^*Q_jXQ_jV_j) = Tr(Q_jXQ_j). Fix a code state ρ_0 and write Q^⊥=I-Q. Then R(X) = R_0(QXQ) + Tr(Q^⊥ X)ρ_0 is completely positive and trace preserving. It extends R_0 on operators supported in Q H.

    Exact mathematical passage
    Q^\perp=I-Q
\bigcapUse in source · 1 passage

Search aliases: ⋂ bigcap

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  • Use in source · Read passage · 02_strengthened.tex, line 2216

    [Physical compression is not a closure test] Let H_phys=⋂_aKer C_a and let P_phys be its orthogonal projector. Then P_phys[C_a,C_b]P_phys=0 for every pair a,b, whether or not the constraint span closes.

    Exact mathematical passage
    
    \Hcal_{\phys}=\bigcap_a\Ker C_a
    
\bigcap_aUse in source · 1 passage

Search aliases: ⋂_a bigcap

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  • Use in source · Read passage · 02_strengthened.tex, line 2216

    [Physical compression is not a closure test] Let H_phys=⋂_aKer C_a and let P_phys be its orthogonal projector. Then P_phys[C_a,C_b]P_phys=0 for every pair a,b, whether or not the constraint span closes.

    Exact mathematical passage
    
    \Hcal_{\phys}=\bigcap_a\Ker C_a
    
\langleUse in source · 5 passages

Search aliases: ⟨ langle

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  • Use in source · monograph_atlas.tex, line 431

    nnegative entries and column sums one. Conjugate by the unitary Z. The spectrum and positivity of the quadratic form are preserved, but both off-diagonal entries become -1/4. Thus positivity as an operator is not entrywise positivity and does not by itself give a Markov interpretation. headA useful finite positive kernel For this nonnegative H, vectors u_a and times t_a≥0 satisfy ∑_a,b⟨ u_a,e^-(t_a+t_b)Hu_b⟩ = ∑_a e^-t_aHu_a ^2≥0. The factorization makes positivity transparent. It remains a fini…

    Exact mathematical passage
    
    \sum_{a,b}\langle u_a,e^{-(t_a+t_b)H}u_b\rangle
    =\left\|\sum_a e^{-t_aH}u_a\right\|^2\ge0.
    
\rangleUse in source · 5 passages

Search aliases: ⟩ rangle

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  • Use in source · monograph_atlas.tex, line 431

    nnegative entries and column sums one. Conjugate by the unitary Z. The spectrum and positivity of the quadratic form are preserved, but both off-diagonal entries become -1/4. Thus positivity as an operator is not entrywise positivity and does not by itself give a Markov interpretation. headA useful finite positive kernel For this nonnegative H, vectors u_a and times t_a≥0 satisfy ∑_a,b⟨ u_a,e^-(t_a+t_b)Hu_b⟩ = ∑_a e^-t_aHu_a ^2≥0. The factorization makes positivity transparent. It remains a fini…

    Exact mathematical passage
    
    \sum_{a,b}\langle u_a,e^{-(t_a+t_b)H}u_b\rangle
    =\left\|\sum_a e^{-t_aH}u_a\right\|^2\ge0.
    

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