Multiparticle Lattice Gas Model for a Fluid: Application to Ballistic Annihilation

Cellular automata (CA) and lattice Boltzmann (LB) models are two possible approaches to simulate fluidlike systems. CA models keep track of the many-body correlations and provide a description of the fluctuations. However, they lead to a noisy dynamics and impose a restriction on the possible values of the viscosity. On the other hand, LB models are numerically more efficient and offer much more flexibility to adjust the fluid parameters, but they neglect fluctuations. Here we propose a new multiparticle lattice model which reconciles the two approaches. Our method is tested on the problem of ballistic annihilation in two dimensions for which the fluctuations are known to play an important role.