Temperature dependence of the bulk viscosity within lattice simulation of SU(3) gluodynamics

In this paper, the temperature dependence of the SU(3) gluodynamics bulk viscosity is studied within lattice simulations. To carry out this study, we measure the correlation function of the trace of the energy-momentum tensor for a set of temperatures within the range T/Tc∈(0.9,1.5). To extract the bulk viscosity from the correlation function, we apply the Backus-Gilbert method and the Tikhonov regularization method. We show that the ratio ζ/s is small in the region T/Tc≥1.1–1.2, and in the vicinity of the transition T/Tc≤1.1–1.2 it quickly rises. Our results are in agreement with previous lattice studies and in a reasonable agreement with other phenomenological approaches. Obtained values of the bulk viscosity are significantly larger than perturbative results, which confirms that quark-gluon plasma is a strongly correlated system.