title: Spectral statistics of chaotic systems with a pointlike scatterer
abstract: The statistical properties of a Hamiltonian H0 perturbed by a localized scatterer are considered. We prove that if H0 describes a bounded chaotic motion, the universal part of the spectral statistics is not changed by the perturbation. This is done first within the random matrix model. Then it is shown by semiclassical techniques that the result is due to a cancellation between diagonal diffractive and off-diagonal periodic-diffractive contributions. The compensation is a very general phenomenon encoding the semiclassical content of the optical theorem.
authors.affiliation: Laboratoire de Physique Theorique et Modeles Statistiques, Universite de Paris-Sud, Batiment 100, 91405 Orsay Cedex, France.
authors.initials: E
authors.lastname: Bogomolny
authors.initials: P
authors.lastname: Leboeuf
authors.initials: C
authors.lastname: Schmit