Abstract

Noise is usually perceived as a limiting factor for dynamical systems. Indeed, in the largest variety of devices, the increase of the noise amplitude leads to a degradation of the output signal. In nonlinear systems this is not necessarily true; it has been shown that finite amount of noise may induce a dynamical state which is, according to some indicator, more ”ordered”. Examples of such behavior are, for instance, the enhancement of the decay time of a metastable state (Noise Enhanced Stability), the synchronization with a weak periodic input signal (Stochastic Resonance) and the formation of convective structures in spatially extended systems (Noise-Sustained Structures). Recently, Pikovsky and Kurts studied in Ref. [1] the effect of noise in the Fitz Hugh - Nagumo model of an autonomous excitable oscillator. They showed that the fluctuations of the time between successive excitable pulses are minimized for a well-defined amount of the input noise. They named such a behavior Coherence Resonance

© 2000 IEEE