TheoPhysEval benchmark: GPT-6-Astra solves 49 of 50 theoretical physics problems
Thirty-five researchers released TheoPhysEval, a 50-problem benchmark of unpublished theoretical physics calculations with verifiable answers. GPT-6-Astra (running in OpenAI's Codex environment) solved 49 of 50 problems (98%) at an average cost under $3 per problem; Anthropic's Opus 5.5 scored 92%, Gemini 3.8 Flash 68%, and several open-weight models scored lower. Tests were run with and without web access and authors note models often performed well without internet, implying substantial memorization of the literature; the dataset and test code are available on Hugging Face.