Hyperbolicity of a model for polyatomic gases in relativistic extended thermodynamics

The hyperbolicity of a model for relativistic extended thermodynamics of polyatomic gases is here proved for every time direction \(\xi _\alpha \); moreover, an expression for the production terms of the field equation is proposed which encloses as particular cases the variant of the Anderson–Witting model already known in the literature, but also a new variant of the Marle model. With these expressions, it is shown that the field equations satisfy automatically the requirement of a non-negative entropy production.