STATIONARY NONEQUILIBRIUM ENSEMBLES FOR THERMOSTATED SYSTEMS

We explore the transient and the stationary behavior of proposed measu res for chaotic dynamical systems, with particular reference to thermo stated nonequilibrium systems. The Kawasaki distribution function form alism, which is based on the Liouville equation, is shown to give a go od description of the transient measure. An orbital measure with a sup port based on unstable periodic orbits is shown to give the stationary measure. Also, we emphasize the importance of determining the set of observables by which a nonequilibrium measure can be defined. The stat ionarity of these methods is considered in both the periodic orbit the ory and the Liouville picture for the change in the distribution funct ion.