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DY: Fachverband Dynamik und Statistische Physik

DY 30: Reaction-Diffusion Systems

DY 30.5: Talk

Thursday, March 17, 2011, 11:15–11:30, ZEU 118

Coupling of pacemakers and irregular excitation patterns in reaction-diffusion systems — •Claudia Lenk¹, Mario Einax², J. Michael Koehler¹, and Philipp Maass² — ¹Institut für Physik, Technische Universität Ilmenau, Germany — ²Fachbereich Physik, Universität Osnabrück, Germany

Reaction-diffusion (RD) systems describe pattern formation in many areas as, e.g., chemical reactions, population dynamics, and the propagation of electrical excitations in the brain or heart. They allow one also to study the mechanisms that lead to irregular, chaos-like excitation patterns and related pathological states in physiologic applications. In this talk we report on the generation of irregular excitation patterns due to coupling of different pacemakers in two types of spatially separated RD-systems, the Belousov-Zhabotinsky reaction (BZR) and a simple model for atrial fibrillation. Theoretical calculations are carried out for two different RD-models, the FitzHugh-Nagumo equations and the minimal model of Bueno-Orovio et al [1]. Experiments of the BZR are conducted in a gel system with periodic pattern of the catalyst Ferroin. The regularity of the excitation patterns is analyzed by the entropy of the frequency distribution and by the synchronization properties between the two pacemakers.

A. Bueno-Orovio, E. M. Cherry, F. H. Fenton, JTB 253, 544 (2008).