On Cancellations of Ultraviolet Divergences in Supergravity Amplitudes

TL;DR

This paper explores unexpected ultraviolet divergence cancellations in supergravity amplitudes, linking them to gauge invariance and crossing symmetry, and discusses the roles of supersymmetry and string dualities in these phenomena.

Contribution

It provides a physical explanation for the cancellations in supergravity amplitudes and analyzes the influence of gauge invariance, crossing symmetry, supersymmetry, and string dualities.

Findings

Ultraviolet divergences are canceled in supergravity amplitudes independently of supersymmetry.

Gauge invariance and crossing symmetry are key to understanding these cancellations.

Supersymmetry and string dualities further influence the structure of multiloop amplitudes.

Abstract

Concrete calculations have pointed out that amplitudes in perturbative gravity exhibit unanticipated cancellations taming their ultraviolet behaviour independently of supersymmetry. Similar ultraviolet behaviour of N=4 super-Yang-Mills and N=8 maximal supergravity has explicitly been observed until three loops. These cancellations can be connected to two manifest features of gravitational theories: firstly gauge invariance from diffeomorphism symmetries and secondly that amplitudes are colourless and exhibits crossing symmetry. We will give a simple physical explanation of the cancellations exhibited in gravity amplitudes. We will discuss these two properties in turn as well as the role of supersymmetry and string theory dualities in the structure of multiloop amplitudes in supergravity.