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DY: Dynamik und Statistische Physik

DY 30: Spiral Formation and Feedback

DY 30.7: Talk

Monday, March 7, 2005, 11:45–12:00, TU H3010

Multi-armed spiral formation driven by defects in an excitable medium — •Maria Inmaculada Rodriguez Ponce and Franz Schwabl — Lehrstuhl 5 für theoretische Physik, Physik Department, Technische Universität München, James-Franck-Strasse, D-85747 Munich, Germany

We simulated a cellular automaton based on a model for Dictyostelium discoideum cells (Dd’s) in order to study the appearance of multi-armed spirals and their stability in an excitable medium. In a certain parameter region, the model displays stable spiral structures, as well as concentric rings and other spatio-temporal structures. We focus on the appearance of multi-armed spirals when they are formed by the presence of defects inthe lattice. We describe the multi-armed spiral formation in terms of tip-tip interaction and defect size. We find that the number of arms in the spiral almost solely depends on the defect size.