Location: HILL 705
Date & time: Thursday, 14 September 2017 at 2:00PM - 3:00PM
Abstract: In many nonequilibrium systems, the averaged values of local observables in a stationary state are dominated by the local equilibrium behavior and it is very difficult to observe deviations from it in numerical experiments. However, fluctuations of global magnitude capture the existence of corrections beyond local equilibrium. In particular, we show some numerical results about the energy fluctuation in a two dimensional hard disk system in contact with reservoirs at different temperatures and subjected to an external applied force. In addition we use the Onsager-Machlup theory to study fluctuations in the heat current of these systems.
First we show that the current minimizers of the associated Langrangian should have spatial structure in contrast to the common belief. We apply this result to the study of the heat flow in the d=2 KMP model and the WASEP (driven diffusive system). We extract some novel properties in both cases: from quasi universal conditional temperature profiles in the first case to dynamic phase transitions in the space of trajectories in the second one.