Dresden 2011 – wissenschaftliches Programm

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DY: Fachverband Dynamik und Statistische Physik

DY 10: Posters I

DY 10.43: Poster

Montag, 14. März 2011, 17:00–19:00, P4

Evolution of a scroll ring in an oscillatory medium close to a Neumann boundary — •Fabian Paul and Harald Engel — Institut für Theoretische Physik, Technische Universität Berlin, Hardenbergstr. 36, D-10623 Berlin, Germany

It is shown that scroll ring solutions of the complex Ginzburg-Landau equation can be stabilized by the interaction with a Neumann boundary. Two antagonistic tendencies govern the dynamics of the scroll ring: Boundary-induced expansion and contraction caused by positive filament tension. Depending on the initial conditions and the chosen parameters, due to the interaction with the Neumann boundary the contraction of the scroll ring is slowed down or even terminated at a finite radius. For certain parameter values numerical simulations suggest a limit cycle regime with alternating phases of contraction and expansion of the scroll ring. This object reminds of an autonomous pacemaker in an active medium close to the transition between excitable and oscillatory kinetics.