Calculation of Graviton Scattering Amplitudes using String-Based Methods

TL;DR

This paper employs string-inspired methods to compute one-loop four-graviton scattering amplitudes in perturbative gravity, demonstrating simplifications through supersymmetric decompositions and unitarity constraints.

Contribution

It introduces a string-based approach to calculate complex gravity amplitudes and explores supersymmetric decompositions and unitarity constraints for simplification.

Findings

Successfully computed all one-loop four-graviton amplitudes with various internal particles.

Demonstrated significant simplification using supersymmetric multiplet decomposition.

Discussed the role of unitarity in constraining gravity amplitudes.

Abstract

Techniques based upon the string organisation of amplitudes may be used to simplify field theory calculations. We apply these techniques to perturbative gravity and calculate all one-loop amplitudes for four-graviton scattering with arbitrary internal particle content. Decomposing the amplitudes into contributions arising from supersymmetric multiplets greatly simplifies these calculations. We also discuss how unitarity may be used to constrain the amplitudes.