The large time behaviour in quantum field theory and quantum chaos
The purpose of this paper is to obtain an exact general result about the large time behaviour of certain matrix elements of the evolution operator. The so-called ``ABC-formula'' obtained has the form \(\langle U\rangle= \exp^{At+B+C(t)}\). The constants \(A\) and \(B\) and the decreasing function \(C(t)\) are computed in the framework of perturbation theory. The formula includes the higher order corrections to the well known Weisskopf-Wigner approximation and to the stochastic (van Hove) limit. The theory developed is applicable to the large but not infinite time scales at which the \(S\)-matrix description is not valid.NEWLINENEWLINEFor the entire collection see [Zbl 0953.00049].
scientific article