OpenAI claim summary for Math-495
mathematicsTop Open Problemscontributionliterature_reportClaim: literature report
Summary of a claim published in openai/math; not a claim by this platform.
The finite-field scalar pair ab=1$\neq$ba gives finite-support convolution maps on all configurations. The map for b has the map for a as left inverse, is injective, and fails surjectivity because ba$\neq$1. This is the all-configurations convention in both original surjunctivity records. Within these assumptions, this is a claimed negative answer to the stated question.
Limitations: The linked openai/math material has not been examined or verified by the platform.
Manuscript
Contents
Gottschalk Surjunctivity Problem
OpenAI's claim
The linked manuscripts present the following claims by OpenAI: A finite characteristic-two field and a finitely presented group are claimed to produce a scalar one-sided inverse pair; the resulting shift is injective without being onto and the group is nonsofic; For a particular odd prime $p$, the authors claim a one-sided inverse defect over a field with $p^4$ elements, together with a nonsurjective injective shift; Another construction claims a torsion-free, finitely presented $G$ for which $\mathbb F_2[G]$ contains $a,b$ satisfying $ab=1$ and $ba\ne1$. Together they give a claimed negative answer in the matching scope.Mathematical statement of the claimed result
Result 1.
Take a finite field $K$ with $\operatorname{char}K=2$. The constructed group $G$ is finitely presented and has an element of odd prime order. Two finite group-ring sums meet \[ a_{\mathrm{out}},b_{\mathrm{out}}\in K[G],\qquad a_{\mathrm{out}}b_{\mathrm{out}}=1,\qquad b_{\mathrm{out}}a_{\mathrm{out}}\ne1. \] Its specification uses terminating finite-set and finite-field computations. Unlike the torsion-free companion, this particular group contains torsion.Result 2.
Define the integers \[ m=\binom{1200}{600},\qquad p=\min\{h\in\mathbb Z:h>1,\ h\mid(m!)^2+1\}. \] The claimed example has $p$ an odd prime, $|K|=p^4$, and a specified finitely generated group $G$ containing torsion. Its finite sums $a,b\in K[G]$ satisfy \[ ab=1\quad\hbox{and}\quad ba\ne1. \] This is an example in a specified odd characteristic, rather than a theorem for each odd prime.Result 3.
The construction supplies a torsion-free, finitely presented group $G$, with a finite two-dimensional $K(G,1)$, and elements of its characteristic-two group algebra satisfying \[ a,b,c\in\mathbb F_2[G],\qquad ab=1,\quad ac=0,\quad c\ne0,\quad ba\ne1. \] In particular, $a\ne0$ and $e=ba$ obeys $e^2=e$, $e\notin\{0,1\}$. Thus this same example supplies failures of direct finiteness, absence of zero divisors, and triviality of scalar idempotents. These assertions concern $\mathbb F_2[G]$; the separate integral-unit assertion is not a consequence.Outline of the argument
Incidence data and polynomial pairings first give a defective inverse pair of matrices. A geometric group-embedding construction preserves the defect, and character packing realizes the matrix algebra inside a larger group algebra; dual convolution gives the cellular-automaton consequence.The construction uses translation representations of finite groups: a high-degree subspace is killed on one side and a weighted pairing supplies the other annihilation. Finite group identifications and a quadratic field tower package these local relations into the scalar inverse pair; the claim concerns the specified prime rather than all odd characteristics.
An unequal-side parity pattern supplies the one-sided inverse relation in labeled graphs. Weighted counts handle repeated edge traversals, and a separator reduces arbitrarily large planar arrangements to bounded path collections; cone attachment and root separation then preserve the inverse defect while proving torsion-freeness.
Formal verification
For family 197, the documented Lean entries include the scalar inverse defects in the specified characteristics and an operator-invertible determinant counterexample. The characteristic-two search recipe is included, but the nonsofic consequence, the extra spectral-integral conclusion, and the later torsion-free construction are outside the selected statements. The listed Comparator files areGroupRingDeterminant.lean, KaplanskyDirectFiniteness.lean, KaplanskyFinitelyPresented.lean, OddKaplansky.lean. Named declarations include OAI.GroupRingDeterminant.main, OAI.KaplanskyCounterexample.finitelyPresented_counterexample, OAI.OddKaplansky.main_theorem. This site has not executed the Lean code. The scope descriptions do not certify the remaining manuscript arguments.Status caveat
OpenAI attributes these manuscripts to work by an internal model. Its release cautions that arguments without formalization can contain mistakes. This catalogue has not independently checked the proofs; the labels report the mathematical claims attributed to OpenAI.Sources
- OpenAI, A Counterexample to Kaplansky's Direct-Finiteness Conjecture in Characteristic Two, 2026-09-23; citation key
OAI:A-Counterexample-to-Kaplanskys-Direct-Finiteness-Conjecture-in-Characteristic-Two-September-23-2026. PDF (GitHub); PDF (direct); Manuscript page and citation; Latest version; Statement source: thm:main. - OpenAI, A Counterexample to Kaplansky's Direct-Finiteness Conjecture in Odd Characteristic, 2026-09-26; citation key
OAI:A-Counterexample-to-Kaplanskys-Direct-Finiteness-Conjecture-in-Odd-Characteristic-September-26-2026. PDF (GitHub); PDF (direct); Manuscript page and citation; Latest version; Statement source: op:main. - OpenAI, A Torsion-Free Group Algebra That Is Not Directly Finite, 2026-10-04; citation key
OAI:A-Torsion-Free-Group-Algebra-That-Is-Not-Directly-Finite-October-4-2026. PDF (GitHub); PDF (direct); Manuscript page and citation; Latest version; Statement source: thm:main. - Family 197: Lean scope.
- Comparator GroupRingDeterminant.json.
- Comparator GroupRingDeterminant.lean.
- Comparator KaplanskyDirectFiniteness.json.
- Comparator KaplanskyDirectFiniteness.lean.
- Comparator KaplanskyFinitelyPresented.json.
- Comparator KaplanskyFinitelyPresented.lean.
- Comparator OddKaplansky.json.
- Comparator OddKaplansky.lean.
- Family 197: Reasoning summary.
- OpenAI catalogue entry.