%0 Journal Article
%T Quantum Averaging I: Poincar¨¦--von Zeipel is Rayleigh--Schr£¿dinger
%A Wolfgang Scherer
%J Physics
%D 1994
%I arXiv
%R 10.1088/0305-4470/27/24/028
%X An exact analogue of the method of averaging in classical mechanics is constructed for self--adjoint operators. It is shown to be completely equivalent to the usual Rayleigh--Schr\"odinger perturbation theory but gives the sums over intermediate states in closed form expressions. The anharmonic oscillator and the Henon--Heiles system are treated as examples to illustrate the quantum averaging method.
%U http://arxiv.org/abs/quant-ph/9412010v1