PSI Announces Aaronson–Ambainis Conjecture Proof: Non-Public Anthropic Model, Lean Formalization Open-Sourced
On 2026-11-06, Physical Superintelligence (PSI, @psipbc) said its internal research system, running non-public Anthropic model instances, produced a complete proof of the Aaronson–Ambainis conjecture (open since 2008) on day three, accepted by Lean, then improved the result twice. The research page and Lean 4 formalization repo are public. Vendor wording; no journal peer review yet; the README still asks humans to check that the formal statement matches the printed conjecture.

Key Takeaways
- Sources: PSI research page 2026-11-06 + @psipbc original post + GitHub physical-superintelligence/aaronson-ambainis
- Claim: complete proof on day three, accepted by Lean; two later improvements also Lean-accepted (vendor wording)
- Implication: if the conjecture holds, quantum machines get at most polynomial speedups on random unstructured inputs; PSI now calls it a theorem
- Checkability: public Lean 4.33/Mathlib repo; four main theorems with no sorry/extra axioms; README still leaves statement fidelity to human readers
- Limits: Anthropic model unnamed, no journal peer review, paper prose not machine-checked — cite as vendor claim