2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/15764Energy absorption by driven chaotic systems, the theory of energy spreading and quantal Brownian motion are considered. In particular we discuss the theory of a classical particle that interacts with quantal chaotic degrees of freedom, and try to relate it to the problem of quantal particle that interacts with an effective harmonic bath.36-page lecture notes of the course in Varenna school, Session CXLIII "New Directions in Quantum Chaos", Italy (July 1999)Chaotic DynamicsCondensed Mattertext