Wednesday 23 Mar 2016: Dynamics seminar: Dynamics of wave patterns in excitable and oscillatory media
Hans Dierckx - Ghent University
Many natural systems including the oscillating Belousov—Zhabotinsky chemical reaction and electrical signalling in the heart can be effectively described by a set of coupled reaction-diffusion equations. I will review some of my recent work on the dynamics of wave patterns in these media.
First, I present a variational principle for non-linear wave propagation. I show that wave front evolution is driven by maximising occupied volume while minimising the free surface area of the front.
Second, I discuss the phase-locking of rotating spiral waves. If an external (e.g. electrical) field is applied which rotates at a frequency close to the natural rotation frequency of the spiral wave, it is possible to phase-lock the spiral wave to the externally imposed frequency. In three dimensions, this technique allows restabilising scroll wave turbulence.
Finally, I present the recent discovery of a spiral chimera state, i.e. a spiral wave with phase-randomised core, in sets of oscillators with local coupling.