Supertranslations from Scattering Amplitudes

TL;DR

This paper introduces a method using on-shell scattering amplitudes to systematically capture supertranslations, a type of asymptotic symmetry, to all orders in perturbation theory in gravitational settings.

Contribution

It provides a novel on-shell framework to understand supertranslations and their relation to gravitational observables in asymptotically Minkowski spacetimes.

Findings

Method captures supertranslations to all orders in perturbation theory.

Connects scattering amplitudes with asymptotic symmetry transformations.

Enhances understanding of gauge invariance in gravitational waveforms.

Abstract

On-shell methods have found a new application to local observables such as asymptotic radiation fields and gravitational waveforms. While these observables are invariant under small gauge transformations, they are known to depend on a choice of asymptotic gauge; in gravity on asymptotically Minkowski spacetimes, this is a choice of BMS frame. In this letter, we provide a method for capturing these supertranslations, to all orders in perturbation theory, using the on-shell framework of scattering amplitudes.