OpenAI reports the cubic three-torus isoperimetric profile

In the unit cubic flat three-torus, every volume-minimizing region is a ball, a circular tube about a shortest closed geodesic, a coordinate slab or the complement of one of these, in the predicted volume ranges, including both types at the transition volumes 4π/81 and 1/π.

Sources for this record

What was already known

Balls were known to minimize at sufficiently small volumes and coordinate cuts at half volume. The full ball–tube–slab profile and all transition equality cases remained conjectural.

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 Notable

Determines the complete isoperimetric profile and classifies all minimizers of the cubic flat three-torus.

Limitations

Classification is up to ambient isometry and null-set changes; the statement concerns the unit cubic flat three-torus.

Technical verification Formal (Lean 4)

OpenAI reports a Lean proof matching the selected claim.

Formal checking

The pinned Lean note covers the profile, existence and classification of all minimizers, including transition equality cases.

Checker
OpenAI-reported Lean 4 / Comparator
Scope
In the unit cubic flat three-torus, every volume-minimizing region is a ball, a circular tube about a shortest closed geodesic, a coordinate slab or the complement of one of these, in the predicted volume ranges, including both types at the transition volumes 4π/81 and 1/π.
Basis
Reported by the linked checker
Evidence source

Checking a formal statement does not establish that it matches the original problem.

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