Factorization Properties of Soft Graviton Amplitudes

TL;DR

This paper demonstrates that soft graviton amplitudes in quantum gravity can be factorized into hard and soft components using path integral resummation, with soft gravitons modeled by Wilson line operators, advancing understanding of gravity-gauge theory relations.

Contribution

It provides evidence for the factorization of eikonal graviton amplitudes and models soft gravitons via Wilson line operators, extending previous theoretical frameworks.

Findings

Soft graviton amplitudes factorize into hard and soft parts.

Soft gravitons are modeled by vacuum expectation values of Wilson line operators.

Factorization-breaking terms are subleading in the eikonal approximation.

Abstract

We apply recently developed path integral resummation methods to perturbative quantum gravity. In particular, we provide supporting evidence that eikonal graviton amplitudes factorize into hard and soft parts, and confirm a recent hypothesis that soft gravitons are modelled by vacuum expectation values of products of certain Wilson line operators, which differ for massless and massive particles. We also investigate terms which break this factorization, and find that they are subleading with respect to the eikonal amplitude. The results may help in understanding the connections between gravity and gauge theories in more detail, as well as in studying gravitational radiation beyond the eikonal approximation.