Calculation of dissipative phase space corrections

Abstract text:

Calculation of dissipative phase space corrections

Dénes Molnár1

1 Department of Physics and Astronomy, Purdue University, West Lafayette, IN 47907, USA

There is a lot of interest in heavy ion physics in systems that are near local thermal equilibrium. In such systems, particle distributions acquire nonthermal corrections (i.e., they are not Boltzmann). Hydrodynamic simulations of heavy-ion reactions use such corrected distributions to convert the hydrodynamic fields to particles at the end of the calculation. A self-consistent approach to relate dissipative phase space corrections to hydrodynamic fields (namely, the energy momentum tensor and conserved currents) is provided by linearized kinetic theory [1].

Mathematically, the problem boils down to solving a linear integral equation for the phase space corrections as a function of momentum, which is then recast as the maximization of some functional. Numerically, the maximization is done using a finite variational basis of functions. The most time consuming part is the calculation of numerous variational "matrix elements", which involve four-dimensional integrals. I will discuss how the integration is performed using an implementation of adaptive Gauss-Kronrod quadrature on GPUs, and present results calculated for a multi-species hadron gas with self-consistent shear viscous and bulk viscous corrections.

[1] D. Molnar and Z. Wolff, PRC 95, 024903 (2017) 

Dénes Molnár

End of talk: 6/22/2018 3:40:00 PM

Start of talk: 6/22/2018 3:20:00 PM