Anthropic's AI model computed a scattering amplitude with nine loops, surpassing the previous theoretical physics limit for the planar N=4 super-Yang-Mills simplified model. The previous record of eight loops was established by Lance Dixon and collaborators at the SLAC National Accelerator Laboratory. Claude performed the calculations largely unsupervised over several days in a specialized Claude Science environment after receiving a single prompt, spending between $1,000 and $2,000 on compute costs.

Scattering amplitudes are formulas used by physicists to predict particle behavior, but most research stops at two or three loops because computational requirements increase exponentially with each addition. The achievement followed a challenge from physicist and science writer von Hippel to solve a frontier problem within a typical academic budget. Lance Dixon independently verified the results.