Supertranslations from Scattering Amplitudes
arXiv:2408.15961
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.
9 pages. v2: improved discussion of the hard charge