QUANTUM TIME-DELAY IN CHAOTIC SCATTERING - A SEMICLASSICAL APPROACH

We study the universal fluctuations of the Wigner-Smith time delay for systems which exhibit chaotic dynamics in their classical limit; We p resent a new derivation of the semiclassical relation of the quantum t ime delay to properties of the set of trapped periodic orbits in the r epeller. As an application, we calculate the energy correlator in the crossover regime between preserved and fully broken time reversal symm etry. We discuss the range of validity of our results and compare them with the predictions of random matrix theories.