Devil-staircase behavior of dynamical invariants in chaotic scattering

A crisis in chaotic scattering is characterized by the merging of two or more nonattracting chaotic saddles. The fractal dimension of the resulting chaotic saddle increases through the crisis. We present a rigorous analysis for the behavior of dynamical invariants associated with chaotic scattering by utilizing a representative model system that captures the essential dynamical features of crisis. Our analysis indicates that the fractal dimension and other dynamical invariants are a devil-staircase type of function of the system parameter. Our results can also provide insight for similar devil-staircase behaviors observed in the parametric evolution of chaotic saddles of general dissipative dynamical systems and in communicating with chaos.