OpenAI claim summary for Math-380
mathematicsTop Open Problemscontributionliterature_reportClaim: literature report
Summary of a claim published in openai/math; not a claim by this platform.
The source equates amenability and unitarizability for all discrete groups, hence proves the target implication. Its construction of nonunitarizable representations with arbitrarily small excess uniform bound strengthens the converse direction.
Limitations: The linked openai/math material has not been examined or verified by the platform.
Manuscript
Contents
The Dixmier Unitarisability Problem
OpenAI's claim
OpenAI presents a mathematical result relevant to this question in the selected manuscript. Discrete-group amenability is claimed equivalent to unitarizability of all uniformly bounded complex Hilbert representations.Mathematical statement of the claimed result
Result 1.
A uniformly bounded representation $\pi:G\to\operatorname{GL}(\mathcal K)$ is unitarizable when it is similar to a unitary representation. The source claims for every discrete group \[ G\text{ amenable}\quad\Longleftrightarrow\quad G\text{ unitarizable}. \] Its strengthened assertion says that for every nonamenable $G$ and every $\varepsilon>0$, there is a nonsimilar-to-unitary representation satisfying \[ \sup_{g\in G}\|\pi(g)\|\le1+\varepsilon. \] For countable $G$, the witnessing complex Hilbert space may be separable; countability is not required for the equivalence.Outline of the argument
Nonamenability supplies sparse assignments that are turned into weighted block operators. Their invariant-kernel obstruction rules out a similarity to unitaries for the constructed bounded representation, giving the converse to the established amenable implication.Formal verification
For family 251, the documented theorem gives amenability--unitarizability equivalence for arbitrary discrete groups and almost-unitary nonunitarizable witnesses; countable groups have separable witnesses. The later strong-Ulam theorem is not selected. The listed Comparator files areDixmier.lean, DixmierAllDiscrete.lean. Named declarations include OAI.Dixmier.current_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, Unitarizability implies amenability for discrete groups, 2026-09-23; citation key
OAI:Unitarizability-Implies-Amenability-for-Countable-Groups-September-23-2026. PDF (GitHub); PDF (direct); Manuscript page and citation; Latest version; Statement source: thm:main. - Family 251: Lean scope.
- Comparator Dixmier.json.
- Comparator Dixmier.lean.
- Comparator DixmierAllDiscrete.json.
- Comparator DixmierAllDiscrete.lean.
- OpenAI catalogue entry.