Eikonal methods applied to gravitational scattering amplitudes

TL;DR

This paper extends eikonal and factorization techniques from gauge theories to gravity, demonstrating that IR divergences in graviton scattering are governed by exponential behavior of one-loop divergences, with no further subleading IR contributions.

Contribution

It introduces a gravitational Wilson line framework to analyze IR divergences and confirms the exponential structure of IR divergences in graviton scattering amplitudes.

Findings

IR divergences in graviton scattering are exponential of one-loop divergences

No additional subleading IR divergences in dimensional regularization

Framework connects gauge theory methods to gravitational amplitudes

Abstract

We apply factorization and eikonal methods from gauge theories to scattering amplitudes in gravity. We hypothesize that these amplitudes factor into an IR-divergent soft function and an IR-finite hard function, with the former given by the expectation value of a product of gravitational Wilson line operators. Using this approach, we show that the IR-divergent part of the n-graviton scattering amplitude is given by the exponential of the one-loop IR divergence, as originally discovered by Weinberg, with no additional subleading IR-divergent contributions in dimensional regularization.