A CAUSAL FORMULATION OF DISSIPATIVE RELATIVISTIC FLUID DYNAMICS WITH OR WITHOUT DIFFUSION

The article proposes a causal five-field formulation of dissipative relativistic fluid dynamics as a quasilinear symmetric hyperbolic system of second order. The system is determined by four dissipation coefficients eta, zeta, kappa, mu, free functions of the fields, which quantify shear viscosity, bulk viscosity, heat conductivity, and diffusion. In the introduction to his Hyperbolic Conservation Laws in Continuum Physics [3], Constantine Dafermos suggests that "the umbilical cord joining continuum physics with the theory of partial differential equations should not be severed, as it is still carrying nourishment in both directions". This paper is part of an attempt to contribute in that spirit.