Bulk viscosity in quasi particle models

Understand

We discuss transport properties of dynamical fluid composed of quasi-particles whose masses depend on temperature and charge chemical potentials.

• Based on the relativistic kinetic theory formulated under the relaxation time approximation, we derive a general expression for the bulk viscosity in the quasi-particle medium.
• We show that dynamically generated particle masses imply an essential modification of the fluid compressibility.
• As an application of our results we consider a class of quasi-particle models with the chiral phase transition belonging to O(4) and Z(2) universality class.