SEMINAIRE MERCREDI 4 FEVRIER 2004
14 heures
Salle Séminaire 5
Centre de Physique Théorique
Marseille-Luminy

Angelo Vulpiani
Dip. di Fisica, Universita La Sapienza - Roma

Title: Diffusive transport and self-consistent dynamics in coupled maps

Abstract: The study of diffusion in Hamiltonian systems has been a problem of
interest for a number of years. We explore the influence of
self-consistency on the diffusion properties of systems described by
coupled symplectic maps. Self-consistency, i.e. the back-influence of
the transported quantity on the velocity field of the driving flow,
despite of its critical importance, is usually overlooked in the
description of realistic systems, for example in plasma physics. We
propose a class of self-consistent models consisting of an ensemble of
maps globally coupled through a mean field. Depending on the kind of
coupling, two different general types of self-consistent maps are
considered: maps coupled to the field only through the phase, and
fully coupled maps, i.e.through the phase and the amplitude of the
external field.