Coherence resonance in chaotic systems

We show that it is possible for chaotic systems to display the main feature s of coherence resonance. In particular, we show that a Chua model, operati ng in a chaotic regime and in the presence of noise, can exhibit oscillatio ns whose regularity is optimal for some intermediate value of the noise int ensity. We nd that the power spectrum of the signal develops a peak at fini te frequency at intermediate values of the noise. These are all signatures of coherence resonance. We also experimentally study a Chua circuit and cor roborate the above simulation results. Finally, we analyze a simple model c omposed of two separate limit cycles which still exhibits coherence resonan ce, and show that its behavior is qualitatively similar to that of the chao tic Chua system.