BGK model for multi-component gases near a global Maxwellian

Abstract

In this paper, we establish the existence of the unique global-in-time classical solutions to the multi-component BGK model suggested in [47] when the initial data is a small perturbation of global equilibrium. For this, we carefully analyze the dissipative nature of the linearized multi-component relaxation operator, and observe that the partial dissipation from the intra-species and the inter-species linearized relaxation operators are combined in a complementary manner to give rise to the desired dissipation estimate of the model We also observe that the convergence rate of the distribution function increases as the momentum-energy interchange rate between the different components of the gas increases.