OpenAI reports a single generator for separable-predual II₁ factors

Every type II₁ factor with separable predual is generated as a von Neumann algebra by one bounded operator, equivalently two self-adjoint operators.

Sources for this record

What was already known

Single generation was known for type I, hyperfinite and properly infinite von Neumann algebras. A direct-integral reduction left type II₁ factors as the unresolved case.

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 generator problem for type II₁ factors with separable predual and, with the established reduction, for all von Neumann algebras with separable predual.

Limitations

Predual separability is required; operator-norm separability and separability of the representing Hilbert space are not.

Technical verification Formal (Lean 4)

OpenAI reports a Lean proof matching the selected claim.

Formal checking

The pinned Lean note proves one-operator generation of every separable-predual type II₁ factor; it also covers a distinct relative-generation theorem.

Checker
OpenAI-reported Lean 4 / Comparator
Scope
Every type II₁ factor with separable predual is generated as a von Neumann algebra by one bounded operator, equivalently two self-adjoint operators.
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