Source authenticated

Kaplansky's direct finiteness conjecture

Theorem 1.1 (September 23): a finite field KK of characteristic two, a finitely presented group GG containing odd-order torsion, and a,b∈K[G]a,b\in K[G] with ab=1ab=1, ba≠1ba\ne1. By Elek-Szabo, GG is not sofic. Companions: for a specified odd prime pp (the least prime factor of ((1200600)!)2+1(\binom{1200}{600}!)^2+1), a field of order p4p^4 and a finitely generated group with torsion (September 26); and a finitely presented torsion-free group with a finite two-dimensional classifying complex and a,b,c∈F2[G]a,b,c\in\mathbb F_2[G] with ab=1ab=1, ac=0ac=0, c≠0c\ne0 (October 4). No counterexample in characteristic zero is possible, and none is claimed.

Exact FrontierDelta

Prior state unknown→disproved

Scope and record

Occurred: Sep 23, 2026

Delta type: SOURCE CLAIM

Assumptions: VibeMathed verification: lean-checked. Publication: announcement. AI contribution: ai-discovered. VibeMathed editorial classifications, scores, notes, relations, and dataset structure are CC BY 4.0. Source statements and linked content retain their own rights.

Canonical aliases: Kaplansky's direct finiteness conjecture · Kaplansky direct finiteness

Confidence: Not scored

Registry verification: lean checked · announcement · candidate

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Attribution

VibeMathed
registry · event recorded by

Unreleased internal OpenAI model
model · ai model contributor · OpenAI

Artifacts and verifiers

Lean proof (OAI.KaplanskyCounterexample.finitelyPresented_counterexample)

lean artifact · pending

Artifact ↗
Comparator statement: KaplanskyFinitelyPresented.lean

lean artifact · pending

Artifact ↗
Comparator statement: KaplanskyDirectFiniteness.lean

lean artifact · pending

Artifact ↗
Lean proof (OAI.OddKaplansky.main_theorem)

lean artifact · pending

Artifact ↗

Compute record

No linked compute attempts recorded.

Lineage and corrections

This event attributed to Unreleased internal OpenAI model

Input: Kaplansky counterexample in characteristic two evidence for this event

Companion: Counterexample in Odd Characteristic (Lean-checked automaton) evidence for this event

Comparator statement: KaplanskyFinitelyPresented.lean evidence for this event

Lean proof (OAI.KaplanskyCounterexample.finitelyPresented_counterexample) evidence for this event

VibeMathed record: Kaplansky's direct finiteness conjecture evidence for this event

Lean proof (OAI.OddKaplansky.main_theorem) evidence for this event

Comparator statement: KaplanskyDirectFiniteness.lean evidence for this event

Companion: A Torsion-Free Group Algebra That Is Not Directly Finite evidence for this event

Theorem 1.1 (September 23): a finite field KK of characteristic two, a finitely presented group GG containing odd-order torsion, and a,b∈K[G]a,b\in K[G] with ab=1ab=1, ba≠1ba\ne1. By Elek-Szabo, GG is not sofic. Companions: for a specified odd prime pp (the least prime factor of ((1200600)!)2+1(\binom{1200}{600}!)^2+1), a field of order p4p^4 and a finitely generated group with torsion (September 26); and a finitely presented torsion-free group with a finite two-dimensional classifying complex and a,b,c∈F2[G]a,b,c\in\mathbb F_2[G] with ab=1ab=1, ac=0ac=0, c≠0c\ne0 (October 4). No counterexample in characteristic zero is possible, and none is claimed. parent of this event

Kaplansky's direct finiteness conjecture parent of this event

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