2003/02/12 by Lutz Brusch, Alessandro Torcini, Markus Baer
Physics and Astronomy · #cond-mat.stat-mech #nlin.CD #nlin.PS
paper · pdf · doi:10.1103/physrevlett.91.108302
published as Phys. Rev. Lett. 91, 108302 (2003) · 4 pages, 4 figures
arxiv created 2003/02/12 · arxiv updated 2009/11/30
Nonlinear waves emitted from a moving source are studied. A meandering spiral in a reaction-diffusion medium provides an example, where waves originate from a source exhibiting a back-and-forth movement in radial direction. The periodic motion of the source induces a Doppler effect that causes a modulation in wavelength and amplitude of the waves (``superspiral''). Using the complex Ginzburg-Landau equation, we show that waves subject to a convective Eckhaus instability can exhibit monotonous growth or decay as well as saturation of these modulations away from the source depending on the perturbation frequency. Our findings allow a consistent interpretation of recent experimental observations concerning superspirals and their decay to spatio-temporal chaos.