OpenAI claim summary for Math-2365
mathematicsTop Open Problemscontributionliterature_reportClaim: literature report
Summary of a claim published in openai/math; not a claim by this platform.
Manuscript 1 (family 320, 2026-10-04): The nonhomeomorphic aspherical pair refutes the Borel-rigidity clause of this broad bundle, but does not decide its idempotent, K-group, signature, FP/FF or higher-dimensional realization clauses.
Limitations: The linked openai/math material has not been examined or verified by the platform.
Manuscript
Contents
Algebraic K-Theory and Rigidity Conjectures for Discrete Groups
OpenAI's claim
Two closed aspherical topological four-manifolds are claimed homotopy equivalent but not homeomorphic, sharing a word-hyperbolic fundamental group; one also admits a self-equivalence outside every homeomorphism homotopy class. The cited manuscript argues for that result; its relation to this problem is specified below.Mathematical statement of the claimed result
Mathematical claim 1.
OpenAI claims closed connected aspherical topological four-manifolds $M,N$ with a common word-hyperbolic fundamental group such that \[ M\simeq N\quad\text{but}\quad M\not\cong N\text{ by any homeomorphism}. \] Aspherical means that the universal cover is contractible; $\simeq$ denotes homotopy equivalence. A second theorem claims a topological four-manifold that is aspherical, closed and connected $M$ and a self homotopy equivalence $f:M\to M$ for which no homeomorphism is homotopic to $f$. These are four-dimensional topological counterexamples; the first excludes homeomorphism existence in any homotopy class.Outline of the argument
Manuscript 1 (family 320, 2026-10-04): Reflected marked chambers retain an odd-cover filling obstruction, and carefully chosen binary label relations eliminate unwanted chamber symmetries. Hyperbolicity and Poincare duality make the outer automorphism group finite, with a controlled normalizer of the realized chamber action. A hypothetical homeomorphism would transport another finite action into that realized subgroup and force an excluded conjugacy.Formal verification
Family 320 has no Lean scope page in this snapshot; no formalization of these manuscript results is listed.This site has not executed the Lean files or checked their dependencies. These descriptions report the scope of the linked declarations, rather than a new verification of the proofs.
Status caveat
OpenAI attributes these results to an internal model. Its release notice cautions that results lacking full formalization can contain mistakes. This site has not independently assessed the proofs; a solved label records the scope of the reported claim.Sources
- OpenAI, Nonhomeomorphic closed aspherical four-manifolds with the same homotopy type, 2026-10-04; citation key
OAI:Nonhomeomorphic-closed-aspherical-four-manifolds-with-the-same-homotopy-type-October-4-2026. PDF (GitHub); PDF (direct); Manuscript page and citation; Latest version; Statement source: thm:pair; Statement source: thm:self-map. - OpenAI catalogue entry.