Perturbation method with triangular propagators and anharmonicities of intermediate strength
Abstract
Description
I propose a new version of the Rayleigh - Schrödinger perturbation method. It admits a lower triangular matrix in place of the usual diagonal propagator. Illustrated on rational anharmonicities polynomial}(x)/polynomial}(x), treated as perturbations of (quasi-)exact anharmonic oscilators. In this sense the method works in an intermediate-coupling regime and bridges the gap between the weak- and strong-coupling expansions.
37 pages (Latex file, incl. 6 tables) plus 6 ps file figures, to be submitted to J. Math. Chem
37 pages (Latex file, incl. 6 tables) plus 6 ps file figures, to be submitted to J. Math. Chem