ABSTRACT
Everyday life and recent experiments suggest that a thermodynamical description of granular media might be feasible (Nowak et al. 1998, Schroter et al. 2005). Given that granular media consist in a large number of grains, there is a strong motivation for providing a statistical ground to this hypothetic thermodynamical description. However, the stationary dynamics of granular media results from the balance of dissipation and forcing by a non thermal source, so that it does not leave any known ensemble invariant and little is known on the typical configurations explored dynamically (Barrat et al. 2000).
