CLUSTERING AND NON-GAUSSIAN BEHAVIOR IN GRANULAR MATTER

We investigate the properties of a model of granular matter consisting of N Brownian particles on a line, subject to inelastic mutual collis ions. This model displays a genuine thermodynamic limit for the mean v alues of the energy, and the energy dissipation. When the typical rela xation time tau associated with the Brownian process is small compared with the mean collision time tau(c) the spatial density is nearly hom ogeneous and the velocity probability distribution is Gaussian. In the opposite limit tau much greater than tau(c) one has strong spatial cl ustering, with a fractal distribution of particles, and the velocity p robability distribution strongly deviates from the Gaussian one. [S003 1-9007(98)07496-1].