MODULATED STANDING WAVES IN A SHORT REACTION-DIFFUSION SYSTEM

We present a study of pattern formation beyond the onset of the wave i nstability in a short model reaction-diffusion system whose length is between 0.5 and 1.5 times the characteristic wavelength of the wave in stability. As the system length is varied, modulated standing waves, c haracterized by short-lived alternating nodes, are found between the d omains of the half-wavelength and the one-wavelength standing waves. T he space-time two-dimensional Fourier spectra of these modulated stand ing waves show large side peaks. The position of these peaks differs f rom that of the fundamental peak by its wavenumber and by the frequenc y of appearance of the alternating nodes. Another region of modulated standing waves is found within the domain of standing-traveling waves.