Speaker: Nicolas Lanchier,
Mathematics and Statistics Department,
ASU

Title: Survival (and coexistence) in spatially explicit metapopulations

Abstract: Interacting particle systems are usually defined as Markov processes on a state space that maps the regular lattice into a finite set of colors, and whose dynamics are described by local interactions. We extend this framework by replacing the usual lattice with a connected graph whose topology dictates how particles interact. This approach allows us to define a version of the contact process including two levels of interactions, ideally suited to model metapopulations. The mathematical analysis of our ``two-scale'' contact process reveals that a single species may survive if it is either a good competitor or a good colonizer. This also suggests that two species may coexist in the presence of two levels of interactions, which is not the case on the regular lattice. This is a joint work with Belhadji.