SpecialityIstituto dei Sistemi Complessi - CNR, Firenze, IT

Heat transport in oscillators chains with long-range interactionsNonlinear low-dimensional assemblies of classical coupled oscillators have been extensively studied as paradigmatic models of heat transport since many years. While for short-range forces there is currently a detailed understanding of the dynamical mechanisms leading to the establishment of the Fourier law or to its breakdown, the case of long-range interacting systems has received much less attention. In this talk I will analyze the basic mechanisms underlying heat transport processes in such systems. After a general overview, I will focus on the case of a phi^4 chain with long-range interactions decaying as a power alpha of the intersite distance. Depending on alpha, both diffusive and superdiffusive transport regimes are identified by means of a dynamical scaling analysis of energy structure factors and excess energy correlations. An effective simplified model of transport based on Lévy flights describes successfully the numerical results. Finally, I will argue that the above results indicate the existence of different hydrodynamic universality classes.