An unreleased Claude pushed the Riemann zeta zero bound from 41.6% to 67.2% across two Claude Code sessions and 31M output tokens.

Anthropic published on August 10 that a research version of Claude improved the lower bound on the proportion of zeta zeros satisfying RH, producing a formally verifiable Lean proof. Validated by Anthropic mathematicians Levent Alpöge and Ralph Furman, reviewed externally by Brian Conrey and Dan Goldston. Anthropic explicitly caps the hype: "We don't expect that the techniques Claude used will lead to proving the Riemann hypothesis," and notes the work synthesized existing results rather than inventing new frameworks. The restraint in the announcement is doing more for credibility than the result.