Free cooling and inelastic collapse of granular gases in high dimensions

The connection between granular gases and sticky gases has recently been co nsidered, leading to the conjecture that inelastic collapse is avoided for space dimensions higher than 4. We report Molecular Dynamics simulations of hard inelastic spheres in dimensions 4, 5 and 6. The evolution of the gran ular medium is monitored throughout, the cooling process. The behaviour is found to be very similar to that of a two-dimensional system, with a sheari ng-like instability of the velocity field and inelastic collapse when colli sions are inelastic enough, showing that the connection with sticky gases n eeds to be revised.