English

Relativistic Viscous Fluid Dynamics and Non-Equilibrium Entropy

High Energy Physics - Theory 2010-01-22 v2 General Relativity and Quantum Cosmology High Energy Physics - Phenomenology Nuclear Theory

Abstract

Fluid dynamics corresponds to the dynamics of a substance in the long wavelength limit. Writing down all terms in a gradient (long wavelength) expansion up to second order for a relativistic system at vanishing charge density, one obtains the most general (causal) equations of motion for a fluid in the presence of shear and bulk viscosity, as well as the structure of the non-equilibrium entropy current. Requiring positivity of the divergence of the non-equilibrium entropy current relates some of its coefficients to those entering the equations of motion. I comment on possible applications of these results for conformal and non-conformal fluids.

Keywords

Cite

@article{arxiv.0906.4787,
  title  = {Relativistic Viscous Fluid Dynamics and Non-Equilibrium Entropy},
  author = {Paul Romatschke},
  journal= {arXiv preprint arXiv:0906.4787},
  year   = {2010}
}

Comments

25 pages, no figures; v2: matches published version

R2 v1 2026-06-21T13:17:58.332Z