The shear viscosity of gauge theory plasma with chemical potentials

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. (c) 2006 Elsevier B.V. All rights reserved.