Quark Matter 2018

Nonequilibrium viscous correction and bulk viscosity in the relaxation time approximation

15 May 2018, 17:00

2h 40m

First floor and third floor (Palazzo del Casinò)

Poster Initial state physics and approach to equilibrium Poster Session

Speaker

Alina Czajka (McGill University)

Description

We present the correct form of the nonequilibrium viscous correction to the phase space density in the relaxation time approximation that properly takes into account the space-time dependence of the thermal mass. We also investigate the impact the correction has on the bulk viscosity. This correction automatically satisfies the Landau matching condition and energy-momentum conservation. It also makes the appearance of the Callan-Symanzyk ${\beta }_{\lambda }$-function natural in the bulk viscosity calculation. The bulk viscosity has the expected parametric form for the Boltzmann gas, while for the Bose-Einstein case, it is affected by the cut-off of infrared divergences. This may be an indication that the relaxation time approximation is too crude to obtain the correct form of the bulk viscosity for quantum gases.

Presentation materials

poster-new-Venice.pdf