Spinning Dragging Strings

TL;DR

This paper employs the AdS/CFT correspondence to calculate the drag force on a heavy quark in a supersymmetric plasma with R-charge, resolving previous discrepancies and analyzing string stability.

Contribution

It provides a unified calculation of the drag force at nonzero R-charge and examines the stability of spinning string solutions, clarifying earlier conflicting results.

Findings

Resolved discrepancies between previous studies on drag force.

Found no instabilities in small fluctuations of spinning strings.

Discussed boundary conditions for dual strings in the D7-brane setup.

Abstract

We use the AdS/CFT correspondence to compute the drag force experienced by a heavy quark moving through a maximally supersymmetric SU(N) super Yang-Mills plasma at nonzero temperature and R-charge chemical potential and at large 't Hooft coupling. We resolve a discrepancy in the literature between two earlier studies of such quarks. In addition, we consider small fluctuations of the spinning strings dual to these probe quarks and find no evidence of instabilities. We make some comments about suitable D7-brane boundary conditions for the dual strings.