New relativistic dissipative fluid dynamics from kinetic theory

Abstract

Starting with the relativistic Boltzmann equation where the collision term is generalized to include nonlocal effects via gradients of the phase-space distribution function, and using Gradʼs 14-moment approximation for the distribution function, we derive equations for the relativistic dissipative fluid dynamics. We compare them with the corresponding equations obtained in the standard Israel–Stewart and related approaches. Our method generates all the second-order terms that are allowed by symmetry, some of which have been missed by the traditional approaches based on the 14-moment approximation, and the coefficients of other terms are altered. The first-order or Navier–Stokes equations too get modified. Significance of these findings is demonstrated in the framework of one-dimensional scaling expansion of the matter formed in relativistic heavy-ion collisions.