We discuss the existence and non-existence of front, domain wall and pulse type traveling wave solutions of a Ginzburg-Landau equation with cubic terms containing spatial derivatives and a fifth order term, in both subcritical and supercritical cases. Our results appear to be the first rigorous existence and non-existence proofs for the full equation with all possible terms derived from second order perturbation theory present.1991 Mathematics subject classification: 58F39, 34C27, 34C35, 34C37, 35Q55.
Background and definitionsOne way to investigate the dynamics of a pattern formation system modeled by a partial differential equation (PDE) of evolution type, with a single space variable, is via the traveling frame reduction. Introducing the traveling coordinate z = x -ct with wave speed c, we get a boundary value problem for a system of ordinary differential equations (ODE). The critical points of these ODEs correspond to the plane waves or the zero amplitude (trivial) wave of the original PDE. The connections, or transitions, between critical points carry important dynamical information. These connections are a subclass (i.e., uniformly translating structures) of the so-called "coherent structures" (e.g. Saarloos and Hohenberg [29,30]). A heteroclinic connection between the zero amplitude wave and a plane wave is called a front. We call a heteroclinic connection between two different plane waves a heteroclinic domain wall. We call a homoclinic connection from a plane wave to itself a homoclinic domain wall. A homoclinic orbit from the zero amplitude wave to itself is called a pulse. For example, in binary fluid convection (see below), these connections correspond to the "boundary layer" between the coexisting conductive state and periodic, confined convective states.Several