Inelastic hard-rods in a periodic potential
  A simple model of inelastic hard-rods subject to a one-dimensional array of identical wells is introduced. The energy loss due to inelastic collisions is balanced by the work supplied by an external stochastic heat-bath. We explore the effect of the spatial non uniformity on the steady states of the system. The spatial variations of the density, granular temperature and pressure induced by the gradient of the external potential are investigated and compared with the analogous variations in an elastic system. Finally, we study the clustering process by considering the relaxation of the system starting from a uniform homogeneous state. 
Fabio Cecconi, Umberto Marini-Bettolo-Marconi, Fabiana Diotallevi,   Andrea Puglisi