According to ChainCatcher citing MTS, an OpenAI AI model has proved half of the Yang-Mills problem, one of the Clay Mathematics Institute’s seven Millennium Prize Problems. A review panel chaired by Nobel laureate David Gross and including Arthur Jaffe, a co-author of the problem’s official statement, supported the work. OpenAI first disclosed the proof on October 26 and said the model completed it in September. The proof was formalized in Lean, a computer language that allows line-by-line verification. Established in 2000, the problem carries a $1 million prize. Winning it still requires proving the mass gap and meeting the institute’s publication and two-year recognition requirements. X user Theo Jaffee said physicists have handled quantum field theory and quantum Yang-Mills theory empirically, but lacked a mathematical formalization explaining why the theory works.