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Colóquio do IF-UFF

Na próxima quarta-feira, 22/09/2010, às 16:00, na sala 201, haverá um colóquio ministrado por Denis Ullmo, da Universidade Paris-Sud/CNRS.

Título do Colóquio: Tunneling in chaotic systems

Resumo:

Despite their genuinely quantal nature, tunneling phenomena are strongly influenced by the underlying classical dynamics of the systems under study. This is illustrated, for instance, within the textbook example of an (integrable) one-dimensional double well potential, for which tunneling rates are dominated by the classical action of the complex path joining the two wells. I will review here recent (and less recent) developments in the understanding of tunneling between regular islands in a dynamical regime where chaos and regularity coexist. The non-integrable dynamics profoundly modify the tunneling mechanisms we are used to in integrable systems, giving signicantly richer, and more complex, behaviors. I will demonstrate that it is however possible to obtain a quantitative understanding of the tunneling rates in this regime, and stress in particular the role of the chaotic motion and of the classical nonlinear resonances.