String theory and the KLT-relations between gravity and gauge theory including external matter

TL;DR

This paper investigates the KLT relations connecting gravity and gauge theory amplitudes, analyzing their validity at leading order and extending to effective Lagrangians for both theories.

Contribution

It provides a detailed examination of KLT factorizations at leading order and explores their applicability to generic effective Lagrangians in gravity and Yang-Mills theories.

Findings

KLT relations hold at O(1) in α' for scalar amplitudes

Extension of KLT-mapping to effective Lagrangians

Insights into gravity-gauge theory amplitude relations

Abstract

We consider the Kawai-Lewellen-Tye (KLT) factorizations of gravity scalar-leg amplitudes into products of scalar-leg Yang-Mills amplitudes. We check and examine the factorizations at O(1) in $\alpha'$ and extend the analysis by considering KLT-mapping in the case of generic effective Lagrangians for Yang-Mills theory and gravity.