RELATIVISTIC THEORIES OF DISSIPATIVE FLUIDS

The simple Navier-Stokes equations for dissipative fluids, translated into relativity, form a parabolic-and hence mathematically nonviable-system. There have been formulated numerous alternative theories, consisting instead of hyperbolic equations-theories that necessarily involve more dynamical variables and more free functions than does the simple Navier-Stokes theory. It is argued that, these mathematical differences notwithstanding, the physical content of these hyperbolic theories is in most cases precisely the same as that of Navier-Stokes. (C) 1995 American Institute of Physics.