OpenAI reports Gigli’s Alexandrov curvature characterization

For every integer n≥2 and real κ, a complete separable metric space is an n-dimensional Alexandrov space of curvature at least κ exactly when its Hausdorff-measure metric space has full support, is RCD((n−1)κ,n), and has Gigli distributional sectional curvature at least κ on the original global test classes.

Sources for this record

What was already known

Alexandrov lower curvature bounds were known to imply suitable Ricci-curvature structure. Gigli defined the distributional tensor and conjectured that its lower bound, with the RCD structure, also characterizes Alexandrov curvature.

AI involvement AI-led

OpenAI credits itself as manuscript author and states that its internal frontier model produced the results in this release. Individual human input is not detailed enough to establish task-only autonomy.

OpenAI is named as author on the manuscript, and its release attributes the results to an internal frontier model. The individual human input is not detailed enough to establish autonomy.

Importance Major

Resolves Gigli’s characterization conjecture in dimensions at least two.

Limitations

The reference measure must be n-dimensional Hausdorff measure and the original global test classes matter. The linked Lean note checks a weak-Hessian geodesic transfer lemma, not the full equivalence.

Technical verification Reported

Reported is the default when evidence for a higher level is insufficient. The OpenAI-authored manuscript reports and argues the result, but the reviewed sources do not document a completed check of the full assessed claim.

Human understanding Few

Few is the default when evidence for a higher level is insufficient. No named person is documented as explaining the central argument for this assessed contribution.

Correction and publication history

2026-10-18 · publication

Primary manuscript, attribution, prior-work, and scoped checking review for non-notifying local inclusion.

Read this published revision