The weak inhomogeneous Duffin-Schaeffer conjecture
Koukoulopoulos and Maynard (2020) proved the Duffin-Schaeffer conjecture: for with , almost every has infinitely many reduced fractions with . For a fixed shift , unweighted divergence does not suffice without monotonicity (Ramirez; Chow-Hauke-Pollington-Ramirez), and the coprime-numerator inhomogeneous version is false. The weak inhomogeneous conjecture (Yu 2021, Question 1.2; Chow-Technau 2024, Conjecture 1.22; Beresnevich-Hauke-Velani 2024, Conjecture 2), proved for rational shifts by Beresnevich-Hauke-Velani, asks: for every fixed and every with , does hold for infinitely many , for almost every ?
- Result
- Proved(see note)
- Status
- Candidate (review pending)
- AI contribution
- AI-discovered
- Method
- Argument
- Field
- Metric Diophantine approximation
- Posed by
- H. Yu, J. Number Theory (2021), Question 1.2; named by Chow and Technau (2024, Conjecture 1.22); also Beresnevich, Hauke and Velani (2024), Conjecture 2
- Year posed
- 2021
- Years open
- 5y
- Solved
- 2026-09-25
- Model
- Unreleased internal OpenAI model
- Vendor
- OpenAI
- Collaborators
- —
- Verification
- Unreviewed
- Publication
- Announced
- Collection
- OpenAI math release (October 2026), version adc7f12
- Significance
- 30 / 100
- Disclosed cost
- —
- Wikipedia
- No dedicated article
What was actually shown
Theorem 1.1: for every fixed and finite-valued with , almost every satisfies for infinitely many ; the null set may depend on and . Corollary 1.2 gives the Hausdorff-measure analogue via mass transference. The arithmetic core adapts the Koukoulopoulos-Maynard common-pivot method (as simplified by Green-Walker). It proves no convergence converse, no quantitative asymptotic, no coprime-numerator statement, and no result uniform in the shift.
What the AI did
The OpenAI math release (github.com/openai/math, commit adc7f12) states that its results were produced by an unreleased internal OpenAI model under one fixed procedure, averaging about three hours of ChatGPT Pro thinking compute per result. This result is not among the README's stated exceptions (the Re(s) > 11/12 zero-free region write-up and the Hodge conjecture for CM abelian varieties). The manuscript is credited to OpenAI alone and names no human author.
Verification
No independent mathematician has checked this yet. Checked here: the abstract, introduction and Theorem 1.1 of the TeX source, read against the conjecture as stated in the three sources the manuscript cites; the proof was not refereed. The statement covers every real shift, including irrational ones, with arbitrary nonmonotone and unrestricted numerators. The paper notes that the coprime-numerator version is false (Hauke-Treuer-Maynard-Pollington; He-Liao, both 2026), so this entry concerns only the weak form. No Lean formalization is supplied for this family.