Persistence Of Collective Fluctuations In N-Body Metaequilibrium Gravitating And Plasma Systems

Starting from a metaequilibrium state (in the Vlasov limit), the time scale of the fluctuations exhibited by systems of one-dimensional charged particles is computed. This study is given both for plasma and gravitational systems. The use of the multiple water-bag model allows an analytical treatment for bath collective and individual modes. These results are compared with those obtained by numerical simulations of N-body systems. Finally, it is numerically shown that collective effects are responsible for the long time scale of phase-space holes structures. [S1063-651X(98)10612-8].