6533b7d2fe1ef96bd125eab4

RESEARCH PRODUCT

Moment equations in a Lotka-Volterra extended system with time correlated noise

D. ValentiL. Schimansky-geierX. SailerBernardo SpagnoloM. Iacomi

subject

Competing specieDichotomous noiseSettore FIS/02 - Fisica Teorica Modelli E Metodi MatematiciStatistical Mechanics (cond-mat.stat-mech)Spatially extended Lotka–Volterra systemMean field approachFOS: Physical sciencesCondensed Matter - Statistical MechanicsMean field approach; Spatially extended Lotka–Volterra system; Competing species; Dichotomous noise

description

A spatially extended Lotka-Volterra system of two competing species in the presence of two correlated noise sources is analyzed: (i) an external multiplicative time correlated noise, which mimics the interaction between the system and the environment; (ii) a dichotomous stochastic process, whose jump rate is a periodic function, which represents the interaction parameter between the species. The moment equations for the species densities are derived in Gaussian approximation, using a mean field approach. Within this formalism we study the effect of the external time correlated noise on the ecosystem dynamics. We find that the time behavior of the $1^{st}$ order moments are independent on the multiplicative noise source. However the behavior of the $2^{nd}$ order moments is strongly affected both by the intensity and the correlation time of the multiplicative noise. Finally we compare our results with those obtained studying the system dynamics by a coupled map lattice model.

yearjournalcountryeditionlanguage
2007-01-01
http://arxiv.org/abs/cond-mat/0611358