Temperature dependence of shear viscosity of SU(3)-gluodynamics within lattice simulation

Abstract

In this paper we study the SU(3)-gluodynamics shear viscosity temperature dependence on the lattice. To do so, we measure the correlation functions of the energy-momentum tensor in the range of temperatures T /Tc ∈ [0.9, 1.5]. To extract the shear viscosity we used two approaches. The first one is to fit the lattice data with a physically motivated ansatz for the spectral function with unknown parameters and then determine the shear viscosity. The second approach is to apply the Backus-Gilbert method allowing to extract the shear viscosity from the lattice data nonparametrically. The results obtained within both approaches agree with each other. Our results allow us to conclude that within the range T /Tc ∈ [0.9, 1.5] the SU(3)-gluodynamics reveals the properties of a strongly interacting system, which cannot be described perturbatively, and has the ratio η/s close to the value 1/4π of the N = 4 Supersymmetric Yang-Mills theory.