OpenAI reports vanishing of higher bounded Hochschild cohomology

For every complex von Neumann algebra M and every integer k≥2, each bounded M-valued Hochschild k-cocycle has a bounded M-valued primitive, so Hᵏ_b(M,M)=0.

Sources for this record

What was already known

Degree-one vanishing follows from the Kadison–Sakai inner-derivation theorem. Higher-degree self-coefficient vanishing was known for type I and hyperfinite von Neumann algebras, but remained open for general algebras.

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 the higher-degree part of the Kadison–Ringrose cohomology conjecture.

Limitations

The statement uses ordinary bounded multilinear maps with coefficients in M itself. Degree-one vanishing is an earlier independent result.

Technical verification Formal (Lean 4)

OpenAI reports a Lean proof matching the selected claim.

Formal checking

The pinned Lean note proves vanishing in every degree at least two without separability or type restriction.

Checker
OpenAI-reported Lean 4 / Comparator
Scope
For every complex von Neumann algebra M and every integer k≥2, each bounded M-valued Hochschild k-cocycle has a bounded M-valued primitive, so Hᵏ_b(M,M)=0.
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