title: Relaxation to equilibrium in few-particle adiabatic piston systems.
abstract: A Hamiltonian system with few particles and a heavy adiabatic piston is studied. With ensemble averages based on proper classification of slow and fast variables, a nonequilibrium state is defined and the relaxation from nonequilibrium to equilibrium is investigated. Coherent oscillation, dissipative oscillation damping, and anti-intuition energy transfer of the adiabatic piston are observed by numerical simulations. Noise-driven thermodynamic equations of slow variables are derived, based on the assumption of local equilibrium and the fluctuation-dissipation theorem, to understand and quantitatively reproduce all the above few-body nonequilibrium relaxation features.
authors.affiliation: Department of Physics, Beijing Normal University, Beijing 100875, China.
authors.forename: Haihong
authors.initials: H
authors.lastname: Li
authors.forename: Dahai
authors.initials: D
authors.lastname: He
authors.forename: Zhoujian
authors.initials: Z
authors.lastname: Cao
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.forename: Toyonori
authors.initials: T
authors.lastname: Munakata
authors.forename: Gang
authors.initials: G
authors.lastname: Hu