The shear viscosity of gauge theory plasma with chemical potentials

TL;DR

This paper investigates the shear viscosity of strongly coupled gauge theory plasma with chemical potentials, demonstrating its universal ratio to entropy density via gauge/gravity duality at large 't Hooft coupling.

Contribution

It extends the understanding of shear viscosity in gauge theories by including chemical potentials and proves the universality of the viscosity-to-entropy ratio in this context.

Findings

Shear viscosity to entropy density ratio is universal at large 't Hooft coupling.

Chemical potentials do not alter the universal ratio.

The gauge/gravity duality provides a proof of this universality.

Abstract

We consider strongly coupled gauge theory plasma with conserved global charges that allow for a dual gravitational description. We study the shear viscosity of the gauge theory plasma in the presence of chemical potentials for these charges. Using gauge theory/string theory correspondence we prove that at large 't Hooft coupling the ratio of the shear viscosity to the entropy density is universal.