Mathematical Discovery in the Wild: AI-Guided Proofs in Banach Space Theory

Antonio Acuaviva, Pablo Acuaviva

For every bounded operator T:X→Y with separable Y, T is strictly cosingular if and only if its adjoint T* is strictly singular.

Sources for this record

What was already known

Pełczyński had proved the implication under weak compactness and shown it fails without qualification for nonseparable range; Beanland's separable-range question remained open.

AI involvement AI-autonomous

The model found the central proof for Kevin Beanland’s question. Antonio and Pablo Acuaviva checked, locally corrected and rewrote it.

The paper says the Part II proof search was fully model-driven and humans supplied no next lemma or intermediate mathematics; later human verification and editing do not erase that proof-generation autonomy.

Importance Notable

Settles Beanland’s separable-range question through a weak-star extraction and quotient-factorization argument.

Limitations

The equivalence does not extend to arbitrary nonseparable range.

Technical verification Formal (human)

The two authors report a complete human mathematical check of the printed proof; no machine formalization is claimed.

Formal checking

Human mathematical reading, reference and hypothesis checks, and minor corrections

Checker
Antonio and Pablo Acuaviva
Scope
Theorem 7.2 equivalence for separable Y
Basis
Reported by the linked checker
Evidence source

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

Human understanding Full

The authors explain the earlier weak-compactness boundary and the weak-star extraction/quotient factorization that closes the separable case.

Correction and publication history

2026-10-18 · publication

Settles Beanland’s separable-range question through a weak-star extraction and quotient-factorization argument.

Read this published revision