| Abstract: | We study conducting systems, where a quantity such as heat or particles diffuses. When the system is attached to baths on both sides, a flow is induced. The fluctuations of the field in this setting are very different from their equilibrium counterpart. In particular (1) generic long-range correlations form, and (2) the non-equilibrium analog of the free-energy may be exhibit singular behavior. Both are directly related to the breaking of time-reversal symmetry in non-equilibrium systems. We describe techniques used to discover and study these fluctuations, including novel numerical methods. We show that simple 'toy' models capture much of the behavior, which is otherwise hard to observe and understand. |
