Resonances for intermittent systems

There is increasing theoretical and numerical evidence that for many interesting dynamical systems the power spectrum of an observable A extends to a meromorphic function in the complex frequency plane. The position of the complex poles or 'resonances' is independent of the observable A which is monitored. The authors study the resonances for intermittent dynamical systems by using a probabilistic independence assumption about recurrence times. A close agreement between theory and numerical experiments is obtained.