OpenAI Claims to Have Cracked the Navier–Stokes Millennium Problem, With Lean Proof

AlexKontorovich · x · 2026-09-09

The New York Times reports that OpenAI announced its unreleased new model has solved the Navier–Stokes existence and smoothness problem, one of math's Millennium Problems concerning fluid mechanics equations. The paper comes with a Lean formal proof, and the code repository is public.

The model reportedly needed just 88 hours to solve it. This marks the most dramatic sign yet that AI is transforming higher mathematics, surpassing a year of AI solving long-standing—but less prominent—math problems. OpenAI researcher Sébastien Bubeck called it "a spectacular culmination of the arc we have seen over the past twelve months." Mathematicians are both excited and concerned about the change.

Related event: OpenAI Claims Agent Swarm Solved the Navier–Stokes Millennium Problem(38 posts)→

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