We investigate a model of population dynamics in a random force field, where two competing mechanisms of barrier slowing down and proliferation induced super-diffusion are present simultaneously. A one-loop rg analysis close to the critical dimension dc=2 shows that the random force fixed point is unstable in the presence of a small proliferation term, and flows towards an uncontrolled strong coupling regime. Numerical results in d=1 suggest that a new intermediate diffusion behavior appears, consistent with the rg analysis. We introduce the idea of proliferation assisted barrier crossing and give a Flory like argument to understand qualitatively this non trivial diffusive behavior.
Proliferation assisted barrier crossing and population dynamics / Giardina, irene rosana; Bouchaud, Jean Philippe; Mezard, Marc. - ELETTRONICO. - 553:(2001), pp. 35-40. (Intervento presentato al convegno International Conference on Disordered and Complex Systems tenutosi a KINGS COLL LONDON, LONDON, ENGLAND nel JUL 10-14, 2000) [http://dx.doi.org/10.1063/1.1358160].
Proliferation assisted barrier crossing and population dynamics
GIARDINA, irene rosana;
2001
Abstract
We investigate a model of population dynamics in a random force field, where two competing mechanisms of barrier slowing down and proliferation induced super-diffusion are present simultaneously. A one-loop rg analysis close to the critical dimension dc=2 shows that the random force fixed point is unstable in the presence of a small proliferation term, and flows towards an uncontrolled strong coupling regime. Numerical results in d=1 suggest that a new intermediate diffusion behavior appears, consistent with the rg analysis. We introduce the idea of proliferation assisted barrier crossing and give a Flory like argument to understand qualitatively this non trivial diffusive behavior.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
