Cristina CriddleUpdated Sep 9, 2026 – 4.43pm, first published at 11.42amSan Francisco | OpenAI has become embroiled in a public spat with a mathematician who had been working with a researcher from its arch-rival Anthropic, after the ChatGPT maker announced it had solved one of the biggest problems in the field.OpenAI on Tuesday (Wednesday AEST) announced that an unreleased internal model had solved the Navier-Stokes equation, a complex mathematical question that carries a $US1 million ($1.4 million) prize.Financial TimesSubscribe to gift this articleGift 5 articles to anyone you choose each month when you subscribe.Subscribe nowAlready a subscriber? Fetching latest articles