Physics Colloquium - Spring 2005 - Predators, prey and zealots: studies on a lattice
Dept of Physics & Astronomy
University of Maine, Orono, Maine
Presents
Dr. Ivan T. Georgiev
Post-Doctoral Research Associate, Dept. of Physics
Virginia Polytechnic Institute and State University
Predators, prey and zealots: studies on a lattice.
Abstract:
Studies of the effect of spatial constraints and stochastic fluctuations on a class of lattice predator-prey models show that the Lotka-Volterra's mean-field rate equation picture is invalid. I will show how site occupation constraints can lead to the emergence of an active-to-absorbing or first order phase transitions. In particular, ecologically motivated models with nearest and next-nearest neighbor interactions are discussed. In the second part of my talk I will discuss the dynamics of the voter model in the presence of inhomogeneities (zealots) and will show that their presence results in a nontrivial fluctuating steady state. We obtain an exact (yet formal) expression of the magnetization in the presence of an arbitrary number of ``zealots''. Similarities with electrostatic systems are pointed out.
Friday, April 8, 2005
3:10 pm
140 Bennett Hall
Refreshments will follow in Rm. 114, Bennett Hall
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