Special Session 29: Reactions diffusion equations with applications to spatial ecology and infectious disease

On the evolution of slow dispersal in multi-species communities

Robert Stephen Cantrell
University of Miami
USA
Co-Author(s):    King-Yeung (Adrian) Lam, Ohio State University
Abstract:
For any N $ \geq 2$, we show that there are choices of diffusion rates $d_{i}$, $1 \leq i \leq N$ such that for N competing species which are ecologically identical and have distinct diffusion rates, the slowest disperser is able to competitively exclude the remainder of the species. In fact, the choices of such diffusion rates are open in the Hausdorff topology. Our result provides some evidence in the affirmative direction regarding the conjecture by Dockery et al. in 1998. The main tools include Morse decomposition of the semi-flow and the theory of normalized Floquet principal bundle for linear parabolic equations. A critical step in the proof is to establish the smooth dependence of the Floquet bundle on diffusion rate and other coefficients, which may be of independent interest.