Statistical mechanics of fluidized granular media: Short-range velocity correlations - art. no. 041303

A statistical mechanical study of fluidized granular media is presented. Us ing a special energy injection mechanism. homogeneous fluidized stationary states are obtained. Molecular dynamics simulations and theoretical analysi s of the inelastic hard-disk model show that there is a large asymmetry in the two-particle distribution function between pairs that approach and sepa rate. Large velocity correlations appear in the postcollisional states due to the dissipative character of the collision rule. These correlations can be well-characterized by a state dependent pair correlation function at con tact. It is also found that velocity correlations are present for pairs tha t are about to collide. Particles arrive at collisions with a higher probab ility that their velocities are parallel rather than antiparallel. These dy namical correlations lead to a decrease of the pressure and of the collisio n frequency as compared to their Enskog values. A phenomenological modified equation of state is presented.