title: Semiclassical cross section correlations
abstract: We calculate within a semiclassical approximation the autocorrelation function of cross sections. The starting point is the semiclassical expression for the diagonal matrix elements of an operator. For general operators with a smooth classical limit the autocorrelation function of such matrix elements has two contributions with relative weights determined by classical dynamics. We show how the random matrix result can be obtained if the operator approaches a projector onto a single initial state. The expressions are verified in calculations for the kicked rotor.
authors.affiliation: Fachbereich Physik, Philipps Universitat Marburg, D-35032 Marburg, Germany.
authors.initials: B
authors.lastname: Eckhardt
authors.initials: S
authors.lastname: Fishman
authors.initials: I
authors.lastname: Varga