September 26, 2026
Claude worked almost autonomously for days: solved a 9-loop physics calculation
On Sep 25, Claude calculated a six-particle amplitude in planar N=4 super Yang-Mills at 9 loops. Liam Fitzpatrick and Siddharth Mishra-Sharma gave Fable 5.1 one prompt and asked it to send updates every 4–6 hours. Each of the two solution paths cost approximately $1,000–2,000, and Lance Dixon independently verified the result.
Min Choi
@minchoi
Claude just completed a 9-loop physics calculation that experts considered too difficult to run directly. One prompt. It worked for days with almost no supervision. It cost approximately $1,000–2,000. The result was independently verified. 🤯
New on the Science Blog: Yes, Claude can do Nine Loops. Theoretical physicists predict how particles behave using formulas called scattering amplitudes. These are notoriously hard to compute, so researchers work with layers of increasingly fine corrections called “loops”—each added loop makes the answer more precise but takes exponentially more computation. Most calculations stop at two or three loops. Eight loops was the previous record in a simplified model physicists use as a testing ground (planar N=4 super-Yang-Mills), set by SLAC's Lance Dixon and collaborators. Last month, physicist and science writer @4gravitons issued a challenge: could an AI push past eight loops in this model, using only the compute budget an academic could reasonably access? Given a single prompt describing the nine-loop problem, Claude ran largely unsupervised for days in Claude Science and solved it using methods developed by Dixon and his colleagues, at a total cost of a few thousand dollars. Dixon independently verified the result, and von Hippel wrote about the experience for our blog. Read more: https://www.anthropic.com/research/yes-claude-can-do-nine-loops
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In 2023, Lance Dixon and Andy Liu reached 8 loops in the same simplified model. Claude reached 9 and solved the problem in two ways: bootstrap and the form-factor approach.
A cycle instead of a run. The researchers returned to the agent every 4–6 hours, asked it to continue the calculation, and received reports. Matt von Hippel assessed the result as applying known methods with a large amount of computation, rather than a new method in physics.
Claude Science is available in beta on macOS, Windows, and Linux for Pro, Max, Team, and Enterprise plans. On macOS and Windows, it is installed from the installer on the product page.
Machine-readable result files of up to 1.97 GB have been published, but the calculation programs are not distributed.
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