Coupling constant dependence of the shear viscosity in N=4 supersymmetric Yang-Mills theory
arXiv:hep-th/0406264 · doi:10.1016/j.nuclphysb.2004.11.055
Abstract
Gauge theory - gravity duality predicts that the shear viscosity of N=4 supersymmetric SU(N_c) Yang-Mills plasma at temperature T in the limit of large N_c and large 't Hooft coupling g^2_{YM} N_c is independent of the coupling and equals to ÏN_c^2 T^3/8. In this paper, we compute the leading correction to the shear viscosity in inverse powers of 't Hooft coupling using the α'-corrected low-energy effective action of type IIB string theory. We also find the correction to the ratio of shear viscosity to the volume entropy density (equal to 1/4Ïin the limit of infinite coupling). The correction to 1/4Ïscales as (g^2_{YM} N_c)^{-3/2} with a positive coefficient.
15 pages; references added; a note on the normalization of the gauge coupling constant added in version 3