Real and apparent divergencies in low-frequency spectra of nonlinear dynamical systems

Abstract
We discuss apparent and real 1/fδ divergencies in the small-frequency limit of power spectra of dynamical systems. Apparent 1/f2 divergencies appear in ‘‘type-I’’ intermittency and whenever there is infrequent random hopping between regions with chaotic motion. Real 1/fδ divergencies appear in ‘‘types-II and -III’’ intermittency. The universal properties of these divergencies are discussed in the context of one- and two-dimensional maps.