Calculation of shear viscosity using Green-Kubo relations within a parton cascade

The shear viscosity of a gluon gas is calculated using the Green-Kubo relation. Time correlations of the energy-momentum tensor in thermal equilibrium are extracted from microscopic simulations using a parton cascade solving various Boltzmann collision processes. We find that the pQCD based gluon br...

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Bibliographic Details
Published in:arXiv.org 2011-06
Main Authors: Wesp, C, A El, Reining, F, Z Xu, Bouras, I, Greiner, C
Format: Article
Language:English
Subjects:
Bremsstrahlung
Coupling
Density ratio
Elastic scattering
Mathematical analysis
Shear viscosity
Temperature dependence
Tensors
Viscosity
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Summary:The shear viscosity of a gluon gas is calculated using the Green-Kubo relation. Time correlations of the energy-momentum tensor in thermal equilibrium are extracted from microscopic simulations using a parton cascade solving various Boltzmann collision processes. We find that the pQCD based gluon bremsstrahlung described by Gunion-Bertsch processes significantly lowers the shear viscosity by a factor of 3-8 compared to elastic scatterings. The shear viscosity scales with the coupling as 1/(alpha_s^2\log(1/alpha_s)). For a constant coupling constant the shear viscosity to entropy density ratio has no dependence on temperature. Replacing the pQCD-based collision angle distribution of binary scatterings by an isotropic form decreases the shear viscosity by a factor of 3.
ISSN:2331-8422
DOI:10.48550/arxiv.1106.4306