The momentum analyticity of two-point correlators from perturbation theory and AdS/CFT

TL;DR

This paper investigates the analytic structure of two-point correlators in thermal field theories, revealing a qualitative change in singularity types from weak to strong coupling using AdS/CFT correspondence.

Contribution

It introduces a general principle about the location of singularities in two-point functions and demonstrates a coupling-dependent transition in their nature in N=4 SYM.

Findings

Singularities in correlators are constrained by a general principle.

A transition from branch points to simple poles occurs with increasing coupling.

AdS/CFT correspondence helps analyze the strong coupling regime.

Abstract

The momentum plane analyticity of two point function of a relativistic thermal field theory at zero chemical potential is explored. A general principle regarding the location of the singularities is extracted. In the case of the N=4 supersymmetric Yang-Mills theory at large $N_c$, a qualitative change in the nature of the singularity (branch points versus simple poles) from the weak coupling regime to the strong coupling regime is observed with the aid of the AdS/CFT correspondence.