Propagating Pattern Selection and Causality Reconsidere

Pattern selection, occurring when a nonuniform state of a nonlinear dissipative system propagates into an initially unstable, homogeneous basic state is reconsidered by application of the causality principle. In particular, the nonlinear marginal stability criterion that determines the selection of a nonlinear front solution is replaced by an exact general necessary condition that has never been considered before. The demonstration is based on the causal signaling problem derived in the context of plasma physics.