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DY: Fachverband Dynamik und Statistische Physik

DY 22: Posters I

DY 22.35: Poster

Mittwoch, 28. März 2012, 17:00–19:00, Poster A

Wave nucleation and stabilization in curved media — •Frederike Kneer, Sebastian Boie, Eckehard Schöll, and Markus A. Dahlem — Institut für Theoretische Physik, TU Berlin

We analyzed nucleation of wave segments on curved two-dimensional excitable media stabilized by feedback control. As a generic model of excitation waves in reaction-diffusion media, we used a FitzHugh-Nagumo system in 2 spatial dimensions. In order to find the nucleation threshold, we used feedback control on deformed excitable media such as tori or flat surfaces with local humps or folds. The main results are twofold. First, investigating excitation waves on a torus, we show that the Gaussian curvature of the excitable medium changes the nucleation threshold in a systematic way, i.e. on a negative Gaussian curved area the nucleation size is smaller (higher excitability). Second, and more surprisingly, we observed that a positive Gaussian curvature can even induce a change of stability. We are motivated to study excitation waves in deformed media by neuronal waves in the folded cortex.