Approach to equilibrium in a one-dimensional,two-component gas of Maxwellian molecules

The coupled Boltzmann equations describing the evolution of the velocity distributions of a one-dimensional, two-component gas of Maxwellian molecules are analyzed. When the two species have different masses, the system approaches equilibrium. The complete eigenvalue spectrum of the linearized collision operator is obtained, and is found to exhibit an interesting dependence on the mass ratio. The response of one species to an external field, when the other species is regarded as a host fluid, is also examined.