  Pinning and depinning of wavefronts are ubiquitous features of spatially
discrete systems describing a host of phenomena in physics, biology, etc. A
large class of discrete systems is described by overdamped chains of nonlinear
oscillators with nearest-neighbor coupling and controlled by constant external
forces. A theory of the depinning transition for these systems, including
scaling laws and asymptotics of wavefronts, is presented and confirmed by
numerical calculations.
