Claude's nine-loop amplitude calculation

Claude completed a nine-loop scattering amplitude calculation in the planar N=4 super-Yang-Mills model, surpassing the previous eight-loop record set by SLAC physicist Lance Dixon and collaborators. The challenge was originally posed by physicist and science writer @4gravitons, who asked whether AI could advance past eight loops within a compute budget accessible to an academic. Given a single prompt, Claude ran largely unsupervised inside the Claude Science environment for multiple days, with only periodic continuation prompts and no mid-run scientific corrections, at a total cost of a few thousand dollars, with model inference costs dominating. Dixon independently verified the result using his group's existing verification tools.