One-Loop Soft Theorems via Dual Superconformal Symmetry

TL;DR

This paper investigates one-loop soft theorems in planar N=4 super Yang-Mills theory, revealing universal constraints from dual superconformal symmetry and detailing subleading soft contributions across different helicity sectors.

Contribution

It derives a universal constraint from dual superconformal symmetry to bootstrap subleading soft behavior and computes the complete infrared-finite subleading soft contributions for n-point MHV amplitudes.

Findings

Universal dual superconformal constraint on soft theorems

Complete infrared-finite subleading soft contributions determined

Universality holds within helicity sectors but not across them

Abstract

We study soft theorems at one loop in planar N=4 super Yang-Mills theory through finite order in the infrared regulator and to subleading order in the soft parameter {\delta}. In particular, we derive a universal constraint from dual superconformal symmetry, which we use to bootstrap subleading log {\delta} behaviour. Moreover, we determine the complete infrared-finite subleading soft contribution of n-point MHV amplitudes using momentum twistors. Finally, we compute the subleading log {\delta} behaviour of one-loop NMHV ratio functions at six and seven points, finding that universality holds within but not between helicity sectors.