We show existence of a nonequilibrium steady state for the one-dimensional,
nonlinear BGK model on an interval with diffusive boundary conditions. These
boundary conditions represent the coupling of the system with two heat reservoirs at
different temperatures. The result holds when the boundary temperatures at the two
ends are away from the equilibrium case, as our analysis is not perturbative
around the equilibrium. We employ a fixed point argument to reduce the
study of the model with nonlinear collisional interactions to the linear BGK
model.
Keywords
nonequilibrium steady state, nonlinear BGK model, diffusive
boundary conditions, existence results, heat transfer