Numerical Results for Snaking of Patterns over Patterns in Some 2D Selkov--Schnakenberg Reaction-Diffusion Systems

For a Selkov--Schnakenberg model as a prototype reaction-diffusion system on two dimensional domains, we use the continuation and bifurcation software pde2path to numerically calculate branches of patterns embedded in patterns, for instance hexagons embedded in stripes and vice versa, with a planar interface between the two patterns. We use the Ginzburg--Landau reduction to approximate the locations of these branches by Maxwell points for the associated Ginzburg--Landau system. For our basic model, some but not all of these branches show a snaking behavior in parameter space, over the given computational domains. The (numerical) nonsnaking behavior appears to be related to too narrow bistable ranges with rather small Ginzburg--Landau energy differences. This claim is illustrated by a suitable generalized model. Besides the localized patterns with planar interfaces we also give a number of examples of fully localized patterns over patterns, for instance hexagon patches embedded in radial stripes, and fully localized hexagon patches over straight stripes.