All order gravitational waveforms from scattering amplitudes

TL;DR

This paper computes gravitational waveforms from scattering amplitudes in strong gravitational fields, revealing infinite post-Minkowskian contributions and tail effects, advancing the understanding of waveforms beyond weak-field approximations.

Contribution

It introduces a method to derive gravitational waveforms from strong field scattering amplitudes, including nonlinear and tail effects, extending beyond traditional weak-field approaches.

Findings

Waveforms include infinite post-Minkowskian contributions

Tail effects are explicitly computed in the waveform

Electromagnetic analogs are also analyzed for comparison

Abstract

Waveforms are classical observables associated with any radiative physical process. Using scattering amplitudes, these are usually computed in a weak-field regime to some finite order in the post-Newtonian or post-Minkowskian approximation. Here, we use strong field amplitudes to compute the waveform produced in scattering of massive particles on gravitational plane waves, treated as exact nonlinear solutions of the vacuum Einstein equations. Notably, the waveform contains an infinite number of post-Minkowskian contributions, as well as tail effects. We also provide, and contrast with, analogous results in electromagnetism.