Population dynamics in a random environment

Original · EN

We investigate the competition between barrier slowing down and proliferation induced superdiffusion in a model of population dynamics in a random force field. Numerical results in d=1 suggest that a new intermediate diffusion behaviour appears. We introduce the idea of proliferation assisted barrier crossing and give a Flory like argument to understand qualitatively this non trivial diffusive behaviour. A one loop RG analysis close to the critical dimension dc=2 confirms that the random force fixed point is unstable and flows towards an uncontrolled strong coupling regime.