Nonlinear Networks and Onsager–Casimir Reversibility

Time-invariant networks composed of transformers, linear resistors, and nonlinear reactive elements are studied, and it is shown that the usual noise model for the resistors implies that in an inductorless network, the capacitor charges have, as random processes, a microscopic reversibility property, and more generally, the capacitor charges and inductor fluxes have a generalized reversibility property, provided that the capacitor or inductor characteristics have odd symmetry.