Berlin 2005 – wissenschaftliches Programm

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DY: Dynamik und Statistische Physik

DY 30: Spiral Formation and Feedback

DY 30.6: Vortrag

Montag, 7. März 2005, 11:30–11:45, TU H3010

Feedback-mediated resonant drift of a spiral wave core near a one-dimensional detector — •Vladimir Zykov and Harald Engel — Institut für Theoretische Physik, Technische Universität Berlin, Hardenbergstr. 36, D-10623, Berlin, Germany

It is shown that a spiral wave core can be tracked along a prescribed trajectory through a two-dimensional excitable medium. Each time when the wave front is tangent to a virtual detector line or touches its open end, a short excitability perturbation is globally applied to the medium. Such a relatively simple, robust feedback loop has been successfully realized in a light-sensitive Belousov-Zhabotinsky medium. A theory of the feedback-mediated controlled motion of the spiral core is developed based on very general assumptions about the unforced spiral dynamics. This theory allows to reduce the partial differential equations describing the excitable medium in the presence of the feedback to ordinary differential equations for the coordinates of the spiral core. For the light-sebsitive BZ medium, the predictions of this theory are in perfect agreement both with the obtained experimental data as well as with the results of direct numerical integration of the underlying Oregonator model.