Bifurcation structure of stationary solutions for a chemotaxis system with bistable growth

摘要

From the viewpoint of pattern formation, Keller-Segel systems with growth terms are studied. These models exhibit various stationary and spatio-temporal patterns which are caused by a combination of three effects: chemotaxis, diffusion and growth. In this paper, we consider Keller-Segel system with the cubic growth term known as the Allee effect in ecology and its shadow system in the limiting case that the mobility of biological population tends to infinity. We show the existence and stability of stationary solutions of the shadow system in one space dimension. Our proof is based on the bifurcation theory, a singular perturbation method and a level set analysis. We also show some numerical results on global structures of stationary solutions in the systems by using AUTO package. Moreover, we mention the difference in dynamics between Keller-Segel system with the cubic growth term and that with the logistic growth term with the aid of a computer.