OpenAI claim summary for Math-225
mathematicsTop Open Problemscontributionliterature_reportClaim: literature report
Summary of a claim published in openai/math; not a claim by this platform.
Manuscript 1 (family 305, 2026-09-24): A finitely presented oriented integral PD4 group with a finite free resolution but no closed aspherical topological four-manifold model directly refutes the problem’s all-dimensions-at-least-three realization assertion.
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Manuscript
Contents
Wall's Poincare Duality Group Conjecture
OpenAI's claim
An integral PD4 group is claimed to be finitely presented with finite classifying space but to admit no closed aspherical topological four-manifold realization, refuting dimension-four manifold realization. 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 a group $G$ with a finite presentation and an integral Poincaré complex, finite, oriented and aspherical, of dimension four $Q$ and \[ H^i(G;\mathbb ZG)=0\ (i\ne4),\qquad H^4(G;\mathbb ZG)\simeq\mathbb Z \] with trivial right $G$-action in degree four, but with no closed aspherical topological four-manifold having fundamental group $G$. The trivial $\mathbb ZG$-module has a finite finitely generated free resolution. Thus the claimed counterexample is integral duality with a finite classifying space, not merely rational duality.Outline of the argument
Manuscript 1 (family 305, 2026-09-24): A marked smooth chamber becomes a graph-type Poincare pair after attaching cells along a hyperbolic middle-homology basis, while its boundary forbids a marked graph filling. Reflection closes the pair into an aspherical complex. Any manifold realization would provide a sphere-marked stable product; capping and controlled destabilization recover the forbidden filling, contradicting the chamber obstruction.Formal verification
Family 305 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, A PD4 group without an aspherical manifold model, 2026-09-24; citation key
OAI:A-PD4-group-without-an-aspherical-manifold-model-September-24-2026. PDF (GitHub); PDF (direct); Manuscript page and citation; Latest version; Statement source: thm:main. - OpenAI catalogue entry.