# Anthropic says Claude set a record nine-loop physics calculation

> Anthropic says Claude computed a record nine-loop scattering amplitude calculation.

*Claude computed a scattering amplitude beyond the previous record, working largely unsupervised on a public physics challenge.*

By Behzad Hosseini · WireRead
Canonical: https://wireread.com/news/anthropic-claude-nine-loop-physics-record

Anthropic said on Friday that its Claude AI model computed the nine-loop six-particle scattering amplitude in planar N=4 super-Yang-Mills theory, a calculation beyond the previous eight-loop record set by physicists Lance Dixon and Andy Liu in 2023. The company described the result as evidence of what Claude can do when set loose on a well-defined, unusually difficult technical problem.

Scattering amplitudes predict how particles behave when they interact, and each additional "loop" in the calculation adds precision but makes the underlying mathematics far harder to complete. N=4 super-Yang-Mills is a simplified theory physicists use to develop new calculation techniques, rather than a model of real-world particles, [Anthropic said](https://www.anthropic.com/research/yes-claude-can-do-nine-loops).

Claude answered a public challenge issued on 7 August by physics writer Matt von Hippel, who had put the nine-loop problem forward as a test of what current AI systems could achieve. Anthropic physicists Liam Fitzpatrick and Siddharth Mishra-Sharma gave the model, Claude Fable 5.1 running inside Claude Science, a single instruction and then let it work largely on its own from there.

Claude completed the calculation two separate ways, arriving at consistent results by two distinct methods, taking about a week running on 96 CPUs, at a cost Anthropic estimated at roughly $1,000 to $2,000 per method.

Lance Dixon, a physicist at SLAC, spent about two weeks independently checking the result before it was made public, Anthropic said. Separately, a team led by Song He in Beijing reached most of the same result around the same time, using GPT-6-based AI assistance for some of the constraints in its own, independent calculation.

Dixon said, in comments Anthropic published alongside the result, "it's quite a triumph, in my opinion, for a large language model to execute all of the steps in the complicated recipe we laid out."

Anthropic said it is not claiming new physics from the result. Claude executed a known calculation recipe on an unusually hard symbolic problem, the company said, rather than discovering anything new about how particles actually behave in the real world.

Anthropic did not say whether it plans to attempt a ten-loop calculation or a similar challenge using Claude in future, beyond describing the nine-loop result as a demonstration of the model working largely unsupervised on a well-defined, difficult technical task set by an outside physicist.

The previous record, an eight-loop calculation, had stood since 2023, meaning it took the wider physics research community roughly three years to be surpassed by an AI system working largely on its own over the course of about a week.

Von Hippel had put his challenge to AI companies in general rather than to any one lab. Anthropic's team took up the nine-loop problem and published the result on 25 September, alongside Dixon's independent verification of it.

## Key takeaways

- Claude computed a nine-loop scattering amplitude, beating the previous eight-loop record set in 2023.
- Anthropic physicists gave Claude one instruction and let it work largely alone, taking about a week on 96 CPUs.
- SLAC physicist Lance Dixon spent two weeks independently checking the result.

## Sources

- [Yes, Claude can do nine loops](https://www.anthropic.com/research/yes-claude-can-do-nine-loops) — Anthropic, 2026-09-25