Paper IXReading edition

Open questions and further directions

Reading tools
Reading libraryFind statementsInspect Lean
Switch work

Saved reading

Read side by side

Start reading

Resources & source

Original TeX with line links · Download TeX

The wording and mathematics follow the retained manuscript. This reading format does not add a proof review or extend Lean coverage.

Skip contents and start reading

12 Open questions and further directions

The arithmetic results above resolve Nishibuchi's conjecture throughout its stated parameter range. The local analyticity and differentiability theorem is also complete under its stated invertibility hypothesis. What remains is a set of extensions and sharper classifications, together with the broader questions raised by the original native seed-calculus program.

12.1 Singular persistence beyond an invertible solved block

The weighted lifting theorem allows the solved Jacobian to be noninvertible modulo \(p\) provided that it is invertible over \({\mathbb Q_p}\) with a controlled inverse. This includes a substantial class of lifts often called singular modulo \(p\). The next problem is to understand Jacobians that remain rank-deficient over \({\mathbb Q_p}\), where the inverse construction is no longer available.

For a fixed polynomial system \(F\in{\mathbb Z}[X_1,\ldots,X_d]^e\), a precision \(L\geq1\), and a root \(\bar x\) modulo \(p^L\), let

\[ \mathcal L_{F,L}(\bar x) =\{x'\in({\mathbb Z}/p^{L+1}{\mathbb Z})^d: F(x')=0,\ x'\equiv\bar x\pmod{p^L}\}. \]

The finite obstruction theorem decides whether this set is empty from the residual digit and reduced Jacobian. When it is nonempty, the theorem also determines its cardinality and affine kernel structure. The conclusion concerns one level: vanishing of the obstruction permits the next step, but does not guarantee that subsequent steps are possible.

For example, \(X^2-5\) has the root \(1\) modulo \(2\), and both \(1\) and \(3\) lift it to roots modulo \(4\). Every odd square is \(1\) modulo \(8\), so neither branch continues to a root modulo \(8\). Thus even a successful first correction can lead to branches that stop at the following level.

We seek structural hypotheses and higher obstruction data that control an entire singular branch, including its behavior under coefficient and parameter deformation. One route is to propagate suitable conditions from level to level. Another is to prove existence at all levels in a form that yields compatible branches. The finite obstruction calculus supplies the tests for individual levels, but a persistence theorem needs a further argument linking them. Any general formulation must allow multiple branches, later obstructions, and changes in the rank of the Jacobian.

12.2 Native 13.2: presentation invariance

The original conjecture asks for a canonical finite obstruction packet whose vanishing is necessary and sufficient for a one-level lift in a finitely presented arithmetic seed system. For a fixed finite polynomial presentation, the paper now supplies the precise obstruction

\[ o_{F,\bar x}=[r]\in {\operatorname{coker}}\!\left(J_{F,\bar x}:{\mathbb F}_p^d\longrightarrow{\mathbb F}_p^e\right), \]

where \(r\) is the residual digit. We have proved independence from the chosen integer representative. Invariance under a change of equations or presentation requires more.

The raw cokernel already reveals the difficulty. The presentations \(F=(X)\) and \(G=(X,0)\) describe the same zero locus over every coefficient ring. At zero their Jacobians are, respectively,

\[ {\mathbb F}_p\xrightarrow{\,1\,}{\mathbb F}_p, \qquad {\mathbb F}_p\xrightarrow{\,(1,0)\,}{\mathbb F}_p^2. \]

Their raw cokernels are \(0\) and \({\mathbb F}_p\). Both distinguished obstruction classes vanish, but the ambient obstruction groups are not isomorphic. The example rules out the raw cokernel as a presentation-independent object while leaving open the possibility of an intrinsic obstruction construction.

A precise form of Native 13.2 therefore needs four ingredients:

  1. a category of seed objects, including how the operators, relations, projectors, weights, and topology enter an object;

  2. specified changes of presentation and a proof that they preserve the actual lift problem;

  3. an obstruction object that respects dependencies among the relations, together with comparison maps or a universal property;

  4. a precise meaning of “finite” and “canonical”, and a proof that vanishing is equivalent to the intended one-step continuation.

For commutative algebra presentations, the relation module offers a natural way to account for dependencies among listed equations. To extend this approach to the full seed vocabulary, we would need an encoding that preserves the lift problem, together with a proof of that preservation. This is one of the links still needed between the concrete obstruction theorem and Native 13.2.

12.3 Native 13.3: finite compatibility, completion, and descent

The original proposed form is

\[ X\simeq X_2^{\mathrm{wt}}\times_C\prod_{p>2}'X_p. \]

It leaves \(X\), the distinguished subsets defining the restricted product, the maps to \(C\), the ambient category, and the universal meaning of “smallest” unspecified. In particular, one must decide whether \(X\) is a global object or a completed object.

The linear compatibility theorem provides one concrete part of this program. If two local observations \(J:U\to V\) and \(K:U\to W\) are linear maps from the same correction module, define

\[ C_{J,K}=U/(\ker J+\ker K). \]

The attainable observations \({\operatorname{im}} J\) and \({\operatorname{im}} K\) have canonical labels in this quotient. Equality of labels is equivalent to simultaneous realization by a single correction. The joint image is exactly the fiber product over \(C_{J,K}\), with the proved linear universal property. The declarations are

Komorebi.SharedCorrection.labels_eq_iff_common, Komorebi.SharedCorrection.joint_range_eq_fiber, and Komorebi.SharedCorrection.common_universal.

To apply this result arithmetically, one must construct the common correction module and the observation maps, then show that the resulting compatibility condition agrees with the intended arithmetic one.

Why the global/completed distinction is necessary.

Consider constant sequences with integer initial value. Their global parameter space is \({\mathbb Z}\), while their local parameter spaces are \({\mathbb Z}_p\). Under the canonical local maps, the image of the global objects is the diagonal

\[ D=\{(n)_p:n\in{\mathbb Z}\}\subseteq\prod_p{\mathbb Z}_p. \]

This diagonal is dense: a basic open set specifies finitely many congruences, and the Chinese remainder theorem provides an integer satisfying them. It is proper: the tuple with \(2\)-adic coordinate zero and all odd-adic coordinates one is not the image of an integer. Indeed an integer zero in \({\mathbb Z}_2\) must be zero, contradicting its \(3\)-adic coordinate.

Consequently this canonical global diagonal cannot be an equality locus

\[ \{(a,b):f(a)=g(b)\} \subseteq {\mathbb Z}_2\times\prod_{p>2}{\mathbb Z}_p \]

for continuous maps to a Hausdorff space \(C\). Such an equality locus is closed, as the inverse image of the closed diagonal in \(C\times C\), whereas \(D\) is proper and dense. This topological argument, retained from the native progress note, concerns the stated topological interpretation. It has not been formalized in Lean for this manuscript.

Finite CRT reconstruction leads to the familiar completed object \(\widehat{\mathbb Z}=\prod_p{\mathbb Z}_p\), but does not identify which local tuples come from a single global integer. A complete form of Native 13.3 must therefore specify finite-level compatibility, transition maps and completion, and any additional global descent condition. If recurrence, spectral, or Frobenius information is to supply that condition, it must be expressed through defined maps or constraints on the local data, with a precise account of how they enter \(C\).

The accompanying native/Native_Conjectures_Progress.md records further results in restricted settings: an intrinsic finite \(\operatorname{Ext}^1\) obstruction for finitely presented commutative integer algebras, finite CRT reconstruction for polynomial solution sets, and a characterization of rectangular finite relations by equality of common labels. The obstruction result is a stated specialization of a classical external theorem; the CRT and rectangularity results have prose proofs in the note. These are preserved mathematical progress, with the restrictions and source records given there, rather than Lean completions of the general Native 13.2 and 13.3 statements.

12.4 Arithmetic refinements

Write \(U_{N,j}(n)=j!C_{N,j}(n)\) and \(U_j=U_{4,j}\), and use \(v_p(0)=\infty\) when discussing valuation bounds. The following classification questions remain open in this program.

  1. The remaining higher-difference classification. The new strengthening chapters determine every repeated-step valuation in addresses \(j=0,1\), give the exact criterion for equality in the common mixed-step lower bound there, and determine address-two valuations at all power-of-two orders. What remains is a complete exact formula in address two at the other orders, a full classification in address three, and the amount of additional cancellation in mixed-step cases where the leading term vanishes. Numerical patterns through a finite range do not settle these questions.

  2. Upper-half addresses at larger dyadic rank. The exact first-difference laws now include \(N=2,4,8\) and every lower-half address for \(N=2^a\ge4\). Larger upper-half addresses need a finer classification. Explicit counterexamples show that extrapolating one low-order Newton coefficient to a universal metric law is false. A least period is measured in packet rows; its Euler-degree displacement is \(NP\).

  3. Exact affine Mahler-kernel valuations. For the kernel of Section 2.7, determine exact values of

    \[ v_p\bigl(\Theta_{M,s}(r,k)\bigr),\qquad \Theta_{M,s}(r,k)=[z^r](1+z)^s((1+z)^M-1)^k, \]

    beyond the explicit special families. The minimum valuation of the summands gives a lower bound. Equality requires a separate argument excluding cancellation.

  4. Classical tail root classification and simplicity. The later tail program gives an exact factorization, finite preparation for each fixed depth, and several infinite regular-wall and simplicity families, as summarized in Appendix A. A universal explicit root classification and universal simplicity of the remaining analytic factor are still open. In the exceptional address-one quadratic reduction, the residual task is a nonvanishing discriminant condition. Empty tails remain exactly zero. This problem is distinct from the solved Nishibuchi congruence conjecture.

These refinements build on the proved estimates and exact cases, including the sharp uniform classical dyadic bound and the resolution of Nishibuchi's conjecture.

12.5 Historical material and interface work

The original Paper IX, with corrected proof-status labels, survives as a 28-page PDF. Its recovered formalization supports the framework, Euler coordinates, Mahler differences, unit coordinates, recurrence packets, and CRT results retained in this manuscript. The exact original TeX bytes, original figure-generation files, and complete historical experiment package were not recovered with that PDF. The reconstructed Annals text is reproduced in Appendix D, with its separate provenance and local qualifications. Their older figure and test counts remain historical records; those computations have not been reproduced for this consolidation.

A reconstructed textual copy of the Annals manuscript was also recovered. It includes finite-field mode and subgroup inversion, Fourier invariance, Carmichael and matrix transfer, Amice pullbacks, depleted analytic Euler branches, and extensive polyphase formulas. The sharp classical dyadic kernel and truncation claims from that text have since been connected to checked Lean proofs. The finite polyphase formulas used for explanation here have short explicit algebraic derivations. The remaining claims in that larger historical text have not all been formalized. The source archive retains the text with its provenance, and the statement map distinguishes these historical claims from the certified claims in the present manuscript.

Remaining recovery work includes the precise older odd-prime edge identities, their stated ranges, and the binary digit-sum form of the checked weights. For each item, the work is to recover the formula with its stated range, check the proof, and identify any corresponding Lean declaration. Where the historical source is still missing, the record remains incomplete.

One further task is to connect the older chart constructions to the new regularity theorem. That theorem applies to polynomials with arbitrary coefficients in the ambient field \({\mathbb Q_p}\) and identifies the analytic germ of every continuous ambient-field root selection under its hypotheses. Several older rectangular charts were defined using integer coefficients, integer centers, or subtype-valued maps. Comparing each such historical interface explicitly with the new ambient formulation remains to be done. These comparisons would connect the existing constructions to the proved analytic implicit-function theorem. General singular persistence remains the separate problem described in Section 12.1.

Source and conversion record

Source SHA-256: 421ad10c6c7df64b0097d0c4fdbb5aca7d2889891c138c343e3e999a68c5176f

Unsupported prose commands stop the build. The mathematical expression sequence is checked against the source, with manuscript macros expanded for display.

Conversion records

Notation in Paper IX

Look up a symbol without leaving this chapter. Select text before opening help to search for it.

Search this work’s notation.

    Symbols can have different meanings in different passages. Read each result in its own context.

    Open the full notation index