Stability of strings dual to flux tubes between static quarks in N=4 SYM

TL;DR

This paper investigates the stability of string solutions in the AdS/CFT framework that model flux tubes between static quarks, ensuring only physically relevant configurations are considered in N=4 SYM at finite temperature and Coulomb branch.

Contribution

It formulates and proves general criteria for the perturbative stability of string solutions dual to quark-antiquark flux tubes in various backgrounds.

Findings

Unstable regions are identified and deemed physically irrelevant.

Stability analysis applies to N=4 SYM at finite temperature.

Provides a method to isolate physically meaningful string configurations.

Abstract

Computing heavy quark-antiquark potentials within the AdS/CFT correspondence often leads to behaviors that differ from what one expects on general physical grounds and field-theory considerations. To isolate the configurations of physical interest, it is of utmost importance to examine the stability of the string solutions dual to the flux tubes between the quark and antiquark. Here, we formulate and prove several general statements concerning the perturbative stability of such string solutions, relevant for static quark-antiquark pairs in a general class of backgrounds, and we apply the results to N=4 SYM at finite temperature and at generic points of the Coulomb branch. In all cases, the problematic regions are found to be unstable and hence physically irrelevant.