OpenAI claim summary for Math-308
mathematicsTop Open Problemscontributionliterature_reportClaim: literature report
Summary of a claim published in openai/math; not a claim by this platform.
Theorem 1.1 states that this exact group F is not amenable. 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
Amenability of Thompson's Group \$F\$
OpenAI's claim
OpenAI presents a counterexample in the selected manuscript. Thompson group $F$ is claimed to be nonamenable.Mathematical statement of the claimed result
Result 1.
For Thompson's group $F$, consisting of increasing piecewise-linear homeomorphisms of $[0,1]$ with dyadic breakpoints and slopes powers of two, the source claims \[ F\text{ is nonamenable}. \] This is a statement about the standard discrete group $F$.Outline of the argument
Recursive colors on dyadic partitions are designed to behave under affine transport. Finite averages of these colors give a uniform boundary discrepancy under a fixed set of group moves, contradicting the existence of Følner sets.Formal verification
For family 248, the documented statement rules out a positive normalized invariant mean for standard dyadic Thompson $F$; it does not specify an explicit expansion constant. The listed Comparator files areThompsonNonamenability.lean. Named declarations include OAI.ThompsonNonamenability.thompson_F_nonamenable_composition. 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, Thompson's group F is nonamenable, 2026-09-23; citation key
OAI:Thompsons-group-F-is-nonamenable-September-23-2026. PDF (GitHub); PDF (direct); Manuscript page and citation; Latest version; Statement source: thm:main. - Family 248: Lean scope.
- Comparator ThompsonNonamenability.json.
- Comparator ThompsonNonamenability.lean.
- OpenAI catalogue entry.