Ballistic annihilation kinetics for a multi-velocity one-dimensional   ideal gas
  Ballistic annihilation kinetics for a multi-velocity one-dimensional ideal gas is studied in the framework of an exact analytic approach. For an initial symmetric three-velocity distribution, the problem can be solved exactly and it is shown that different regimes exist depending on the initial fraction of particles at rest. Extension to the case of a n-velocity distribution is discussed. 
Michel Droz, Pierre-Antoine Rey, Laurent Frachebourg and Jaros{\l}aw   Piasecki