Invited by Prof. Zhicheng Wang and associate Prof. Liang Zhang of School of Mathematics and Statistics, Prof.Arnaud DucrotfromUniversity of Le Havre will give a lecture online.

Title: Spreading speeds for multidimensional reaction-diffusion systems of the prey-predator type

Time: 4:00 p.m.,Jul. 22nd, 2021

Conference ID: 983 2172 8282( Zoom Conference)

Abstract:In this talk, we investigate spreading properties of solutions of a large class of two-component reaction–diffusion systems, including prey–predator systems as a special case. By spreading properties we mean the long time behaviour of solution fronts that start from localized (i.e. compactly supported) initial data. Though there are results in the literature on the existence of travelling waves for such systems, very little has been known—at least theoretically—about the spreading phenomena exhibited by solutions with compactly supported initial data. The main difficulty comes from the fact that the comparison principle does not hold for such systems. Furthermore, the techniques that are known for travelling waves such as fixed point theorems and phase portrait analysis do not apply to spreading fronts. In this paper, we first prove that spreading occurs with definite spreading speeds. Intriguingly, two separate fronts of different speeds may appear in one solution—one for the prey and the other for the predator—in some situations. This is based on a joint work with Profs. Thomas Giletti and Hiroshi Matano.