VENDREDI 15 JUIN 2007 15 heures 30 Jour et horaire inhabituels !!! Salle Séminaire 5 Centre de Physique Théorique Marseille-Luminy Rytis Paskauskas Georgia Tech, Atlanta Title: Symbolic dynamics and chaotic transport: hydrogen in crossed fields Abstract: We study an open and strongly chaotic Hamiltonian system, the hydrogen atom in perpendicularly crossed electric and magnetic fields. Good knowledge of symbolic dynamics is a key prerequisite in zeta function and semi-classical trace formalisms, used to calculate statistical averages of classical and quantum systems. Our approach to symbolic dynamics is in terms of periodic orbit and hyperbolic tori partitions. For a given Hamiltonian we identify the attractor, and for the 2-d case we find a 14 letter alphabet that adequately captures salient features of the attractor. In 3-d case we present our program of research and initial work in the direction of symbolic partition of the phase space.