Anthropic Internal Research Model — 2026-08

An unreleased Claude raises the critical-line zero bound for zeta from 41.6% to 67.2%

On 10 August 2026 Anthropic reported that an unreleased research Claude, prompted to attempt the Riemann hypothesis, instead improved the proven lower bound on zeros on the critical line from 41.6% to 67.2%. Anthropic mathematicians and two outside experts examined the argument. The Riemann hypothesis remains open.