Finite-time collapse and soliton-like states in the dynamics of   dissipative gases
  A study of the gas dynamics of a dilute collection of the inelastically colliding hard spheres is presented. When diffusive processes are neglected the gas density blows up in a finite time. The blowup is the mathematical expression for one of the possible mechanisms for cluster formation in dissipative gases. The way diffusive processes smoothen the singularity has been studied. Exact localized soliton-type solutions of the gas dynamics when heat diffusion balances non-linear cooling are obtained. The presented results generalize previous findings for planar flows. 
Itzhak Fouxon