Simon's Problem 1: absolutely continuous spectrum for the weakly disordered Anderson model in dimension three and higher
Let on with iid site potentials uniform on . Anderson (1958) predicted localization at strong disorder; physics predicts that for and weak disorder extended states survive. Absolutely continuous spectrum was proved on the Bethe lattice and on trees (Klein, Aizenman-Sims-Warzel, Aizenman-Warzel), but never on . Simon's Problem 1 asks: for and suitable small disorder, does almost surely have an energy range of purely absolutely continuous spectrum?
- Result
- Proved(see note)
- Status
- Candidate (review pending)
- AI contribution
- AI-discovered
- Method
- Argument
- Field
- Random Schrodinger operators; delocalization
- Posed by
- Barry Simon (Problem 1 in 'Schrodinger operators in the twenty-first century'), formalizing the extended-states prediction going back to Anderson
- Year posed
- 2000
- Years open
- 26y
- Solved
- 2026-09-23
- Model
- Unreleased internal OpenAI model
- Vendor
- OpenAI
- Collaborators
- —
- Verification
- Unreviewed
- Publication
- Announced
- Collection
- OpenAI math release (October 2026), version adc7f12
- Significance
- 65 / 100
- Disclosed cost
- —
- Wikipedia
- No dedicated article
What was actually shown
For each there is such that for every , almost surely a fixed open interval near the bottom band edge (for , ) lies in the spectrum and the spectral restriction to is purely absolutely continuous and nonzero. does not depend on . Not shown: a.c. spectrum in the bulk of the band, the location of a mobility edge, quantum diffusion, uniformity in , or other laws.
What the AI did
The release README says the results were produced by an unreleased internal OpenAI model with a fixed procedure, on average about three hours of ChatGPT Pro thinking compute per result, and that some outputs build on earlier model results. This result is not among the README's exceptions (the Hodge conjecture for CM abelian varieties and the Re(s) > 11/12 zero-free region). The manuscript is authored 'OpenAI' and names no human author.
Verification
No independent mathematician has checked this yet. Checked here: the main theorem was read against Simon's Problem 1 as the manuscript paraphrases it; Simon's text itself was not opened. The proof was not refereed. No Lean formalization exists for this manuscript. The paper itself says it does not locate the mobility edge and does not resolve Simon's diffusion question (Problem 3), and that for d = 3 the disorder threshold is only existential.