Open Conference Systems, StatPhys 27 Main Conference

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Entropy production and the validity of the Vlasov equation for self-gravitating systems
Calvin Alexandre Fracassi Farias, Yan Levin, Renato Pakter

##manager.scheduler.building##: Edificio Santa Maria
##manager.scheduler.room##: Auditorio San Agustin
Date: 2019-07-08 11:45 AM – 03:30 PM
Last modified: 2019-06-15

Abstract


The evolution of self-gravitating systems to out-of-equilibrium stationary states occurs through the mechanism of violent relaxation, a process by which particles exchange energy by moving in a time-changing potential. It’s commonly well accepted that this stage’s dynamics is governed by the Vlasov equation – a kinetic equation whose evolution conserves the system’s entropy. Although being defined in the limit N &rarr &infin, the Vlasov equation is largely used to investigate finite models, the most important being neutral plasmas and self-gravitational systems. Therefore, its entropy production for finite self-gravitating systems was investigated using molecular dynamics simulations. The entropy production time is shown to grows with N^&alpha, with &alpha greater than zero, and in the thermodynamic limit, entropy will remain constant corroborating Vlasov dynamics. Furthermore, the mean field dynamics constructed on the basis of the Vlasov equation is in excellent agreement with the full molecular dynamics simulations.