Gravity and Yang-Mills Amplitude Relations

TL;DR

This paper proves the Kawai-Lewellen-Tye relations connecting gauge theory and gravity amplitudes at tree level using general S-matrix features, introduces a symmetric form, and uncovers new gauge theory amplitude identities.

Contribution

It provides a rigorous proof of the KLT relations and introduces a more symmetric formulation along with new amplitude identities.

Findings

Proof of KLT relations at tree level

A novel symmetric form of the relations

Discovery of new gauge theory amplitude identities

Abstract

Using only general features of the S-matrix and quantum field theory, we prove by induction the Kawai-Lewellen-Tye relations that link products of gauge theory amplitudes to gravity amplitudes at tree level. As a bonus of our analysis, we provide a novel and more symmetric form of these relations. We also establish an infinite tower of new identities between amplitudes in gauge theories.