Post-Minkowskian Radial Action from Soft Limits and Velocity Cuts

TL;DR

This paper introduces a new method leveraging soft graviton limits and velocity cuts to efficiently compute classical post-Minkowskian radial actions in gravitational scattering, achieving high-order results.

Contribution

It presents an innovative extraction scheme for classical physics from quantum scattering amplitudes using unitarity, soft limits, and velocity cuts, extending calculations to fifth post-Minkowskian order.

Findings

Derived scattering amplitudes to fifth post-Minkowskian order

Demonstrated computational efficiency of the method

Extended results to arbitrary dimensions

Abstract

We consider gravitational massive scalar-scalar scattering from unitarity and demonstrate how intermediate soft graviton behavior and the concept of extracting classical physics from localization of integrands on velocity cuts devise an efficient extraction scheme for computing the classical post-Minkowskian radial action perturbatively. We demonstrate the computational efficiency by deriving the scattering amplitudes in the probe regime to the fifth post-Minkowskian order in arbitrary dimensions.