Properties of nonequilibrium steady states (2014-2016)

A nonequilibrium steady state (NESS) occurs when work is performed on a system and the heat so generated is absorbed by a thermostatting mechanism. The system settles into steady state and its properties no longer change. Almost all experimental systems of interest are in a nonequilibrium state, so understanding NESSs is highly significant. Unlike time stationary equilibrium states, the distribution of microstates in a NESS cannot be described by simple closed form distributions. We will determine properties, symmetries and extrema of NESS using concepts and theorems developed for studying transient nonequilibrium states. We will also determine if approximate, physically relevant forms of the phase space distributions can be developed.