A New BGK Model for Relativistic Kinetic Theory of Monatomic and Polyatomic Gases

We propose a possible generalization of the BGK collisional term in the relativistic kinetic theory and we compare our model with previous ones. The present model has the advantage in that it satisfies the conservation of particle number, energy-momentum and the H-theorem in the Eckart frame without constraints on particular local equilibrium state. In the last part of the paper we extend the model to include also the polyatomic gas.