title: Ergodicity breaking and parametric resonances in systems with long-range interactions.
abstract: We explore the mechanism responsible for the ergodicity breaking in systems with long-range forces. In thermodynamic limit such systems do not evolve to the Boltzmann-Gibbs equilibrium, but become trapped in an out-of-equilibrium quasi-stationary-state. Nevertheless, we show that if the initial distribution satisfies a specific constraint-a generalized virial condition-the quasistationary state is very close to ergodic and can be described by Lynden-Bell statistics. On the other hand, if the generalized virial condition is violated, parametric resonances are excited, leading to chaos and ergodicity breaking.
authors.affiliation: Instituto de Física, Universidade Federal do Rio Grande do Sul, Caixa Postal 15051, CEP 91501-970, Porto Alegre, RS, Brazil.
authors.forename: Fernanda P da C
authors.initials: FP
authors.lastname: Benetti
authors.forename: Tarcísio N
authors.initials: TN
authors.lastname: Teles
authors.forename: Renato
authors.initials: R
authors.lastname: Pakter
authors.forename: Yan
authors.initials: Y
authors.lastname: Levin