A calculation of the bulk viscosity in SU(3) gluodynamics

TL;DR

This paper presents a lattice Monte-Carlo calculation of the bulk viscosity in SU(3) gluodynamics, revealing its temperature dependence and behavior near the critical temperature.

Contribution

The study provides the first continuum-limit lattice calculation of the bulk viscosity in SU(3) gauge theory at finite temperature, highlighting its rapid decrease at high temperatures and sharp rise near T_c.

Findings

zeta/s<0.15 at 1.65T_c

zeta/s<0.015 at 3.2T_c

zeta/s rises to 0.5-2.0 just above T_c

Abstract

We perform a lattice Monte-Carlo calculation of the trace-anomaly two-point function at finite temperature in the SU(3) gauge theory. We obtain the long-distance properties of the correlator in the continuum limit and extract the bulk viscosity zeta via a Kubo formula. Unlike the tensor correlator relevant to the shear viscosity, the scalar correlator depends strongly on temperature. If s is the entropy density, we find that zeta/s becomes rapidly small at high T, zeta/s<0.15 at 1.65T_c and zeta/s<0.015 at 3.2T_c. However zeta/s rises dramatically just above T_c, with 0.5<zeta/s<2.0 at 1.02T_c.