Raffaella Burioni

Dipartimento di Fisica, Università di Parma

Rare events and scaling in superdiffusive materials and in field-induced anomalous dynamics

Large fluctuations and rare events play an important role in many physical processes, where heterogeneous spatial structures or temporal inhomogeneities can give rise to anomalous transport. We consider here two effects, driven by rare events, in transport processes. On a class of random Lévy structures, modeled on recent experimental settings, we characterize the superdiffusive behavior by a "single-long-jump approximation", that takes into account the effects of rare events. Then, on Lévy walks and Continuous Time Random Walks with broad trapping distributions, we study the effects of an arbitrary small external field and we show that this can induce an anomalous growth of fluctuations, even when the unperturbed system features standard diffusion.