Comments on gluon scattering amplitudes via AdS/CFT

TL;DR

This paper investigates strong-coupling gluon scattering amplitudes in N=4 super Yang-Mills via AdS/CFT, providing new computations, discrepancies with previous conjectures, and methods for related processes.

Contribution

It offers explicit amplitude calculations at strong coupling, challenges existing conjectures, and introduces a prescription for processes involving local operators and Wilson loops in AdS/CFT.

Findings

Computed amplitudes for specific gluon configurations at strong coupling.

Found disagreement with recent amplitude conjectures.

Provided a string theory method for Wilson loop calculations.

Abstract

In this article we consider n gluon color ordered, planar amplitudes in N=4 super Yang Mills at strong 't Hooft coupling. These amplitudes are approximated by classical surfaces in AdS_5 space. We compute the value of the amplitude for a particular kinematic configuration for a large number of gluons and find that the result disagrees with a recent guess for the exact value of the amplitude. Our results are still compatible with a possible relation between amplitudes and Wilson loops. In addition, we also give a prescription for computing processes involving local operators and asymptotic states with a fixed number of gluons. As a byproduct, we also obtain a string theory prescription for computing the dual of the ordinary Wilson loop, Tr P exp[ i\oint A ], with no couplings to the scalars. We also evaluate the quark-antiquark potential at two loops.