Simon's Problem 2: pure-point spectrum for the two-dimensional Anderson model at every disorder
Let on , with nearest-neighbor hopping and independent site potentials uniform on . The scaling theory of Abrahams, Anderson, Licciardello and Ramakrishnan (1979) predicts no metallic behavior in two dimensions, at any disorder. Rigorous localization was known only at large disorder or at extreme energies (Frohlich-Spencer, Frohlich-Martinelli-Scoppola-Spencer, Aizenman-Molchanov) and near the band edge (Ding-Smart). Simon's Problem 2 asks: for every , does almost surely have pure-point spectrum throughout its spectrum?
- Result
- Proved(see note)
- Status
- Candidate (review pending)
- AI contribution
- AI-discovered
- Method
- Argument
- Field
- Random Schrodinger operators; Anderson localization
- Posed by
- Barry Simon (Problem 2 in 'Schrodinger operators in the twenty-first century'), formalizing the two-dimensional localization conjecture of Abrahams, Anderson, Licciardello and Ramakrishnan
- 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
- 55 / 100
- Disclosed cost
- —
- Wikipedia
- No dedicated article
What was actually shown
For each fixed , the operator on with iid uniform on almost surely has pure-point spectral type with a complete orthonormal eigenbasis, spectrum and dense eigenvalues. The null set may depend on . Not shown: one event for all , bounds uniform in energy, exponential decay of eigenfunctions, dynamical localization, or other single-site laws such as Bernoulli.
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 2 as the manuscript quotes it; Simon's text itself was not opened. The proof was not refereed. Lean: lean/docs/261.md describes a comparator challenge (PlanarAndersonSpectrum.lean) that states only that the spectrum is [-4-h, 4+h], explicitly not the pure-point claim; it is not in formalization.yaml and its solution module is absent at the pinned commit, so it counts for nothing. Scope stated by the paper: uniform single-site law only; no dynamical localization or eigenfunction decay is claimed.