On parabolicity criteria for quasihydrodynamic equation system in the case of a real gas
A quasi-hydrodynamic equation system is studied in the case of the general state equations. The criteria for the non-uniform and uniform Petrovskii parabolicity are derived. A problem on stability of the small perturbations with respect to a constant background is also considered, and the global in time bounds for relative perturbations are given for the Cauchy problem. The results generalize those proven earlier in the case of the perfect polytropic gas.