  The Fluctuation Theorem gives an analytical expression for the probability of
observing second law violating dynamical fluctuations, in nonequilibrium
systems. At equilibrium statistical mechanical fluctuations are known to be
ensemble dependent. In this paper we generalise the Transient and Steady State
Fluctuation Theorems to various nonequilibrium dynamical ensembles. The
Transient and Steady State Fluctuation Theorem for an isokinetic ensemble of
isokinetic trajectories is tested using nonequilibrium molecular dynamics
simulations of shear flow.
