Synchronization and directed percolation in coupled map lattices
  We study a synchronization mechanism, based on one-way coupling of all-or-nothing type, applied to coupled map lattices with several different local rules. By analyzing the metric and the topological distance between the two systems, we found two different regimes: a strong chaos phase in which the transition has a directed percolation character and a weak chaos phase in which the synchronization transition occurs abruptly. We are able to derive some analytical approximations for the location of the transition point and the critical properties of the system.   We propose to use the characteristics of this transition as indicators of the spatial propagation of chaoticity. 
Franco Bagnoli, Lucia Baroni, Paolo Palmerini