Reaction fronts in persistent random walks with demographic stochasticity

Authored by Massimo Cencini, Davide Vergni, Stefano Berti, Angelo Vulpiani

Date Published: 2019

DOI: 10.1103/physreve.99.012404

Sponsors: No sponsors listed

Platforms: No platforms listed

Model Documentation: Other Narrative Mathematical description

Model Code URLs: Model code not found

Abstract

Standard reaction-diffusion systems are characterized by infinite velocities and no persistence in the movement of individuals, two conditions that are violated when considering living organisms. Here we consider a discrete particle model in which individuals move following a persistent random walk with finite speed and grow with logistic dynamics. We show that, when the number of individuals is very large, the individual-based model is well described by the continuous reactive Cattaneo equation (RCE), but for smaller values of the carrying capacity important finite-population effects arise. The effects of fluctuations on the propagation speed are investigated both considering the RCE with a cutoff in the reaction term and by means of numerical simulations of the individual-based model. Finally, a more general Levy walk process for the transport of individuals is examined and an expression for the front speed of the resulting traveling wave is proposed.
Tags
models movement Wave Advance Schemes Propagation Reaction-diffusion systems