Temperature dependence of 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 \(T/T_c \in (0.9, 1.5)\). 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 \(\zeta/s\) is small in the region \(T/T_c \geqslant 1.1-1.2\) and in the vicinity of the transition \(T/T_c \leqslant 1.1-1.2\) 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, what confirms that QGP is a strongly correlated system.