Singular fractal dimension at periodicity cascades in parameters spaces

Abstract: In the parameter spaces of nonlinear dynamical systems, we investigate the boundaries between periodicity and chaos and unveil the existence of fractal sets characterized by a singular fractal dimension. This dimension stands out from the typical fractal dimensions previously considered universal for these parameter boundaries. We show that the singular fractal sets dwell along parameter curves, called extreme curves, that intersect periodicity cascades at their center of stability in all scales of parameters spaces. The results reported here are generally demonstrated for the class of one-dimensional maps with at least two control parameters, generalizations to other classes of systems are possible.