Analysis of the Evans and Baranyai variational principle in dilute gases

Abstract
A variational principle for thermostated nonequilibrium steady states recently proposed by Evans and Baranyai [Phys. Rev. Lett. 67, 2597 (1991)] is analyzed by means of a model kinetic equation for dilute gases. It is shown that the principle does not apply exactly, although deviations from it are small, especially when the gradients are not very large.