VibeMathedMath problems solved with AI

Equivalence of generic stability notions for Keisler measures

Given a first-order theory TT (in discrete or continuous logic) and a Borel-definable global Keisler measure mu\\mu in TT, we show that the following conditions are equivalent: (i)(i) mu\\mu is a frequency interpretation measure; (ii)(ii) mu\\mu is definable and its canonical “random extension” rmur_{\\mu} is generically stable in the randomization theory TRT^{R}; (iii)(iii) mu\\mu is “self-averaging”.

This result establishes a robust notion of generic stability for Keisler measures, which resolves a long-term research objective from previous work. The implications (i)Rightarrow(ii)Rightarrow(iii)(i)\\Rightarrow(ii)\\Rightarrow(iii) were previously established by the authors (for TT discrete). The primary focus of this paper is the reverse implications (iii)Rightarrow(ii)Rightarrow(i)(iii)\\Rightarrow(ii)\\Rightarrow(i), which we obtain through the use of AI models.

Result
Proved(see note)
Status
Resolved
AI contribution
AI-discovered
Method
Argument
Field
Model theory
Posed by
Gabriel Conant, Kyle Gannon
Year posed
2020
Years open
6y
Solved
2026-08-25
Model
ChatGPT 5.5; Kimi K3; Claude Fable 5; ChatGPT 5.6 Sol
Vendor
OpenAI; Moonshot AI; Anthropic
Collaborators
Gabriel Conant, Kyle Gannon, James E. Hanson
Verification
Unreviewed
Publication
Preprint
Significance
20 / 100
Disclosed cost
Wikipedia
No dedicated article

What was actually shown

Let TT be a complete first-order theory in discrete or continuous logic, let MprecmathcalUM\\prec\\mathcal{U}, and let muinmathfrakMx(mathcalU)\\mu\\in\\mathfrak{M}_{x}(\\mathcal{U}) be Borel-definable over MM. The paper proves that the following three conditions are equivalent:\n\n(i)(i) mu\\mu is a frequency interpretation measure (fim) over MM;\n\n(ii)(ii) mu\\mu is definable over MM and its canonical random extension rmur_{\\mu} is generically stable over MOmegaM^{\\Omega};\n\n(iii)(iii) mu\\mu is self-averaging over MM.

The new work proves the reverse implications (iii)Rightarrow(ii)Rightarrow(i)(iii)\\Rightarrow(ii)\\Rightarrow(i) and extends the characterization to continuous logic. The authors therefore make the equivalent conditions into a definitive definition of generic stability for Keisler measures.

The paper also proves a further characterization in terms of an order-property condition and derives consequences for closure under Morley products.

What the AI did

The disclosure is in the abstract itself, not only in an acknowledgment: "The primary focus of this paper is the reverse implications (iii)(ii)(i)(iii)\Rightarrow(ii)\Rightarrow(i), which we obtain through the use of AI models." The dedicated AI Acknowledgment gives the detail, verbatim: "A proof of Theorem 1.1[(iii) \Rightarrow (ii) \Rightarrow (i)] was initially obtained from a ChatGPT 5.5 query focusing on the case when TT is discrete. We were also able to independently find proofs using Kimi K3 and Claude Fable 5. These arguments were heavily reorganized and rewritten by the authors with further assistance from ChatGPT 5.6 Sol. Theorem 5.1 was obtained by the authors by modifying a different result found by ChatGPT while attempting Question 5.3." Worth noting what that describes: the proof came out of a model, and was then independently reproduced by two further models from different vendors. The authors' own labour is reorganizing and rewriting.

Verification

An arXiv preprint (v1, 25 August 2026, math.LO), unrefereed and with no independent endorsement. No mathematics was checked here and there is nothing mechanical to check it against - no formalization, no certificate. Verified here on 26 August 2026: the paper exists at arXiv:2608.24605 with the title and all three authors this entry lists; the statement above is its abstract near verbatim; the AI disclosure appears both in the abstract and in a dedicated AI Acknowledgment, quoted in full above; and the prior work it builds on is real and correctly characterised - Conant and Gannon, Ann. Pure Appl. Logic 171 (2020) for the originating observation, and Conant, Gannon and Hanson, J. Math. Log. (2025) for the chain of implications this paper reverses.

Source

Submitted by VibeGene on

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