Generalized kinetic equations for a system of interacting atoms and photons: theory and simulations

In the present paper, we introduce generalized kinetic equations describing the dynamics of a system of interacting gas and photons obeying very general statistics. In the space homogeneous case, we study the equilibrium state of the system and investigate its stability by means of Lyapounov's theory. Two physically relevant situations are discussed in detail: photons in a background gas, and atoms in background radiation. After having dropped the statistics generalization for atoms but keeping the statistics generalization for photons, in the zero-order Chapmann-Enskog approximation, we present two numerical simulations where the system, initially at equilibrium, is perturbed by an external isotropic Dirac's delta and by a constant source of photons.