OpenAI reports almost-everywhere Fourier convergence in L log L

For every complex-valued function on the circle with finite integral of |f| log(2+|f|), its ordinary symmetric Fourier partial sums converge almost everywhere to f along the full sequence.

Sources for this record

What was already known

The L log L endpoint sufficiency for ordinary Fourier partial sums was a classical conjecture; the manuscript notes prior maximal and weighted endpoint estimates without the full stated convergence conclusion.

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

Settles a classical endpoint question in Fourier analysis.

Limitations

The result is for the circle, ordinary symmetric partial sums, and full-sequence almost-everywhere convergence.

Technical verification Formal (Lean 4)

OpenAI reports a Lean proof matching the selected claim.

Formal checking

The pinned Lean note states the full L log L almost-everywhere convergence theorem for symmetric Fourier sums.

Checker
OpenAI-reported Lean 4 / Comparator
Scope
For every complex-valued function on the circle with finite integral of |f| log(2+|f|), its ordinary symmetric Fourier partial sums converge almost everywhere to f along the full sequence.
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