Universality in the classical limit of massless gravitational scattering

TL;DR

This work demonstrates the universality of the gravitational classical deflection angle of massless particles through O(G^{3}) by studying the high-energy limit of full two-loop four-graviton scattering amplitudes in pure Einstein gravity as well as N≥4 supergravity.

Abstract

We demonstrate the universality of the gravitational classical deflection angle of massless particles through O(G^3) by studying the high-energy limit of full two-loop four-graviton scattering amplitudes in pure Einstein gravity as well as N >= 4 supergravity. As a by-product, our first-principles calculation provides a direct confirmation of the massless deflection angle in Einstein gravity proposed long ago by Amati, Ciafaloni and Veneziano, and is inconsistent with a recently proposed alternative.

Figures (1)

• Figure 1: The scattering configuration showing the impact parameter, $b$, eikonal impact parameter, $b_e$, and the scattering angle, $\chi$.