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arXiv · 1407.7231

Transport coefficients for bulk viscous evolution in the relaxation time approximation

Amaresh Jaiswal·Radoslaw Ryblewski·Michael Strickland
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Abstract

We derive the form of the viscous corrections to the phase-space distribution function due to the bulk viscous pressure and shear stress tensor using the iterative Chapman-Enskog method. We then calculate the transport coefficients necessary for the second-order hydrodynamic evolution of the bulk viscous pressure and the shear stress tensor. We demonstrate that the transport coefficients obtained using the Chapman-Enskog method are different than those obtained previously using the 14-moment approximation for a finite particle mass. Specializing to the case of boost-invariant and transversally homogeneous longitudinal expansion, we show that the transport coefficients obtained using the Chapman-Enskog method result in better agreement with the exact solution of the Boltzmann equation in the relaxation-time approximation compared to results obtained in the 14-moment approximation. Finally, we explicitly confirm that the time evolution of the bulk viscous pressure is significantly affected by its coupling to the shear stress tensor.

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Amaresh Jaiswal, Radoslaw Ryblewski, Michael Strickland. 2014-10-31. Transport coefficients for bulk viscous evolution in the relaxation time approximation. https://doi.org/10.1103/physrevc.90.044908

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