Inherited Twistor-Space Structure of Gravity Loop Amplitudes

TL;DR

This paper explores how twistor-space structures of gravity loop amplitudes can be derived from gauge theory, using unitarity methods and string relations, revealing inherited properties from N=4 super-Yang-Mills theory.

Contribution

It demonstrates that one-loop N=8 supergravity amplitudes inherit twistor-space properties from N=4 super-Yang-Mills theory and connects box coefficients via string relations and unitarity methods.

Findings

Box coefficients in supergravity can be obtained from gauge theory calculations.

Twistor-space properties of supergravity amplitudes are inherited from gauge theory.

Examples illustrate the inheritance of structures between theories.

Abstract

At tree-level, gravity amplitudes are obtainable directly from gauge theory amplitudes via the Kawai, Lewellen and Tye closed-open string relations. We explain how the unitarity method allows us to use these relations to obtain coefficients of box integrals appearing in one-loop N=8 supergravity amplitudes from the recent computation of the coefficients for N=4 super-Yang-Mills non-maximally-helicity-violating amplitudes. We argue from factorisation that these box coefficients determine the one-loop N=8 supergravity amplitudes, although this remains to be proven. We also show that twistor-space properties of the N=8 supergravity amplitudes are inherited from the corresponding properties of N=4 super-Yang-Mills theory. We give a number of examples illustrating these ideas.