OpenAI publishes its Navier-Stokes proof and says it will not claim the Millennium Prize

OpenAI published a paper, PDF, and Lean formalisation showing that a smooth, initially stationary fluid under a continuous external force can develop a finite-time singularity, claiming resolution of statements C and D of the Navier-Stokes Millennium problem while declining the prize. The proof was generated by roughly 10 000 parallel agents over 88 hours, producing 2.7 million messages and about 130 billion tokens; verification took 17 hours with GPT-6 Astra. The Lean code allows anyone to check mathematical correctness, but the Clay Institute’s prize eligibility remains to be decided by the mathematics community.