One-dimensional dynamics for traveling fronts in coupled map lattices

Multistable coupled map lattices typically support traveling fronts, separa ting two adjacent stable phases. We show how the existence of an invariant function describing the front profile allows a reduction of the infinitely dimensional dynamics to a one-dimensional circle homeomorphism, whose rotat ion number gives the propagation velocity. The mode locking of the velocity with respect to the system parameters then typically follows. We study the behavior of fronts near the boundary of parametric stability, and we expla in how the mode locking tends to disappear as we approach the continuum lim it of an infinite density of sites.