Dynamical regimes in the dissipative particle dynamics model

We discuss theoretically the behavior of the velocity autocorrelation funct ion in the dissipative particle dynamics (DPD) model. Two dynamical regimes are identified depending on the dimensionless model parameters. For low va lues of the dimensional friction, a mean field behavior is observed in whic h the kinetic theory for the DPD model provides good predictions, For high values of the friction, collective hydrodynamic effects an dominant. We hav e performed numerical simulations that validate the theory presented. [S106 3-651X(99)16005-7].