Date(s) : 06/11/2018 iCal
11 h 00 min - 12 h 00 min
In this talk, I will present recent results obtained in collaboration with Adrian Lam (Ohio State University, USA). We are interested in the classical monostable Lotka–Volterra competition–diffusion system of two species and more precisely in the associated Cauchy problem when the initial conditions are null, or at least exponentially decaying, in a half-space. Thanks to a sophisticated construction of super- and sub-solutions, we manage to characterize completely the possible pairs of asymptotic spreading speeds for the two species. The main result is unexpected and contradicts a conjecture by Shigesada and Kawasaki: the second speed is not always locally determined and a form of acceleration is possible.