Regensburg 2016 – wissenschaftliches Programm
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DY: Fachverband Dynamik und Statistische Physik
DY 17: Statistical Physics far from Thermal Equilibrium
DY 17.4: Vortrag
Dienstag, 8. März 2016, 10:45–11:00, H48
Universal bounds on current fluctuations — •Patrick Pietzonka1, Andre C. Barato2, and Udo Seifert1 — 1II. Institut für theoretische Physik, Universität Stuttgart — 2Max Planck Institute for the Physics of Complex Systems, Dresden
For current fluctuations in non-equilibrium steady states of Markovian processes, we derive four different universal bounds valid beyond the Gaussian regime. Different variants of these bounds apply to either the entropy change or any individual current, e.g., the rate of substrate consumption in a chemical reaction or the electron current in an electronic device. The bounds vary with respect to their degree of universality and tightness. A universal parabolic bound on the generating function of an arbitrary current depends solely on the average entropy production. A second, stronger bound requires knowledge both of the thermodynamic forces that drive the system and of the topology of the network of states. These two bounds are conjectures based on extensive numerics. An exponential bound that depends only on the average entropy production and the average number of transitions per time is rigorously proved. This bound has no obvious relation to the parabolic bound but it is typically tighter further away from equilibrium. An asymptotic bound that depends on the specific transition rates and becomes tight for large fluctuations is also derived. Our bounds generalize a recently derived relation for the relative uncertainty in current fluctuations [1] and provide a new general class of constraints for nonequilibrium systems.
[1] A. C. Barato and U. Seifert, Phys. Rev. Lett. 114, 158101 (2015)