Sur la théorie des perturbations des états liés

Abstract

Two methods leading to general prescriptions for the construction of the time independent perturbation expansions for bound states to all orders are discussed. The two methods differ by the choice of the zeroth-order wave functions. In both cases, the expansions are simplified by the use of non-orthonormalized zeroth-order wave functions. The terms of the expansions are described by means of diagrams. The accuracy of the expansions is tested by a calculation of two eigen-values of the Mathieu equation.