# Two-Loop Four-Gluon Amplitudes with the Numerical Unitarity Method

## TL;DR

This paper introduces a numerical unitarity method to compute two-loop four-gluon amplitudes, enabling automated, multi-scale calculations relevant for collider physics.

## Contribution

It presents the first numerical approach for two-loop amplitudes using unitarity, demonstrating its universality and potential for automation in collider phenomenology.

## Key findings

- Successful numerical computation of two-loop four-gluon amplitudes
- Analysis of the method's numerical stability and properties
- Reconstruction of analytic amplitude forms

## Abstract

We present the first numerical computation of two-loop amplitudes based on the unitarity method. As a proof of principle, we compute the four-gluon process. We discuss the new method, analyze its numerical properties and apply it to reconstruct the analytic form of the amplitudes. The numerical method is universal, and can be automated to provide multi-scale two-loop computations for phenomenologically relevant signatures at hadron colliders.