Gluon scattering amplitudes from gauge/string duality and integrability

TL;DR

This paper explores the computation of gluon scattering amplitudes in N=4 super Yang-Mills theory at strong coupling using gauge/string duality and integrability, providing analytic expansions and comparisons with perturbative results.

Contribution

It introduces a novel approach to analyze minimal surfaces in AdS_3 via thermodynamic Bethe ansatz and relates boundary entropy to T-functions for amplitude calculations.

Findings

Analytic expansions around regular-polygonal Wilson loops

Close agreement between strong coupling and two-loop rescaled remainder functions

Application of conformal perturbation theory to gauge/string duality

Abstract

We discuss gluon scattering amplitudes/null-polygonal Wilson loops of N = 4 super Yang-Mills theory at strong coupling based on the gauge/string duality and its underlying integrability. We focus on the amplitudes/Wilson loops corresponding to the minimal surfaces in AdS_3, which are described by the thermodynamic Bethe ansatz equations of the homogeneous sine-Gordon model. Using conformal perturbation theory and an interesting relation between the g-function (boundary entropy) and the T-function, we derive analytic expansions around the limit where the Wilson loops become regular-polygonal. We also compare our analytic results with those at two loops, to find that the rescaled remainder functions are close to each other for all multi-point amplitudes.