Global Magnitude Fluctuation Phenomena

Abstract

Global dynamics in many complex physical systems share a common feature: the fluctuations of some adequately defined global magnitude display non-Gaussian statistics, characterized by a non-symmetric probability density functions (pdf) having an exponential or even superexponential tail. This behavior is believed to be originated by finite size effects along with correlation lengths comparable or larger than the system size. Here, we consider three very different systems: a confined turbulent flow, the 2D XY-model and an experimental realization of the Langevin’s equation. Although in all of these systems we find the features previously mentioned, preliminary result of ongoing research show that some of the universality claims found in the current literature deserve a more detailed study.