OpenAI reports a nearly quartic quantum query separation

There are total Boolean functions whose bounded-error randomized query complexity cannot obey any universal bound of the form O((1+Q(f))^α) with α<4, where Q is bounded-error quantum query complexity.

Sources for this record

What was already known

The best known general upper bound had quartic exponent. Earlier total-function separations for randomized versus quantum queries reached exponent 3−o(1), leaving a conjectured cubic bound plausible.

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

Makes the quartic exponent of the general randomized-versus-quantum query upper bound optimal.

Limitations

Both complexities count worst-case bit queries with error at most one third on every input; the claim concerns exponent optimality, not an exact constant-factor equality.

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, and prior-work review for non-notifying local inclusion; technical verification remains Reported.

Read this published revision