Fluctuation theorem for constrained equilibrium systems
Abstract
We discuss the fluctuation properties of equilibrium chaotic systems with constraints such as iso-kinetic and Nos\'e-Hoover thermostats. Although the dynamics of these systems does not typically preserve phase-space volumes, the average phase-space contraction rate vanishes, so that the stationary states are smooth. Nevertheless finite-time averages of the phase-space contraction rate have non-trivial fluctuations which we show satisfy a simple version of the Gallavotti-Cohen fluctuation theorem, complementary to the usual fluctuation theorem for non-equilibrium stationary states, and appropriate to constrained equilibrium states. Moreover we show these fluctuations are distributed according to a Gaussian curve for long-enough times. Three different systems are considered here, namely (i) a fluid composed of particles interacting with Lennard-Jones potentials; (ii) a harmonic oscillator with Nos\'e-Hoover thermostatting; (iii) a simple hyperbolic two-dimensional map.
Cite
@article{arxiv.cond-mat/0601435,
title = {Fluctuation theorem for constrained equilibrium systems},
author = {T. Gilbert and J. R. Dorfman},
journal= {arXiv preprint arXiv:cond-mat/0601435},
year = {2009}
}
Comments
To appear in Phys. Rev. E