The Solomon-Yau least-volume conjecture for minimal hypersurfaces of round spheres
The equator is the least-volume closed minimal hypersurface of the unit sphere . The minimal Clifford products , , are the natural next examples; let be the least of their volumes. Cheng, Li and Yau (1984) proved a dimension-dependent volume gap above the equator, and for the sharp bound follows from the Marques-Neves proof of the Willmore conjecture. Yau's problem list (Problem 31) asks for the next volume level, and Ge and Li (2021, Conjecture 1.12(ii)) state it as the Solomon-Yau conjecture. For every , does every closed minimal hypersurface of that is not totally geodesic have volume at least ?
- Result
- Proved(see note)
- Status
- Candidate (review pending)
- AI contribution
- AI-discovered
- Method
- Argument
- Field
- Minimal hypersurfaces in spheres; volume gaps
- Posed by
- S.-T. Yau, Open problems in geometry (1994), Problem 31; formulated as the Solomon-Yau conjecture by J. Ge and F. Li (2021, Conjecture 1.12(ii))
- Year posed
- 1994
- Years open
- 32y
- Solved
- 2026-09-23
- 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 , a closed connected smooth minimal immersion with non-totally-geodesic image has , attained by a minimizing Clifford product. Intermediate results: for closed embedded non-equatorial minimal hypersurfaces (the lower-bound part of Perdomo's conjecture, also in Nifa 2026) and Clifford rigidity at index . It does not classify hypersurfaces at volume beyond attainment, and says nothing about higher codimension or the next volume levels.
What the AI did
The release README says every result in openai/math was produced by an unreleased internal OpenAI model with a fixed procedure, on average about three hours of ChatGPT Pro thinking compute per result. This result is not one of the README's two exceptions (the Hodge conjecture for CM abelian varieties and the Re(s) > 11/12 zero-free region). The manuscript is authored 'OpenAI' and names no human author.
Verification
No independent mathematician has checked this yet. Checked here: Theorem 1.1 was read against Yau's Problem 31 and Ge-Li Conjecture 1.12(ii). It covers every and smooth closed connected minimal immersions, with volume counted on the domain; the reduction from immersed to embedded uses known multiplicity bounds (Nguyen 2023, Ge-Li 2022). The release has no Lean formalization for this family (lean/docs/349.md does not exist at the pinned commit). The proof is a min-max argument with a dimension induction on cone regularity; it was not refereed here. The same paper proves the lower bound in Perdomo's average-curvature conjecture as a step, which Nifa (2026 preprint) also proves.