Dynamical origin of deterministic stochastic resonance.

We numerically demonstrate stochastic-resonance-like behavior in a deterministic chaotic oscillator system, using a modified Rössler system driven by a sinusoidal external force: intermittent 2 pi phase slips between the system and the external force synchronize with a periodic input signal that weakly modulates the external force in an appropriate parameter range. We show that the dynamical mechanism of this stochastic-resonance-like behavior is explained by a boundary crisis that depends on two bifurcation parameters.