Anthropic posted that an unreleased research version of Claude tackled a problem connected to the Riemann hypothesis. The model did not solve the hypothesis. It raised the proven lower bound for the fraction of zeros of the Riemann zeta function that satisfy the hypothesis from 41.6% to 67.2%. The company linked a page on its site titled Learning more about Claude's mathematical capabilities. Posts quoting the announcement circulated on X with reactions from researchers and investors.