A robust perturbation theory for degenerate states based on exact constants of the motion
Department of Physics, Auburn University - Auburn, Alabama 36849-5311, USA
2 School of Physics, Georgia Institute of Technology - Atlanta, Georgia 30332-0430, USA
Accepted: 15 December 1999
Infinite summations over unperturbed degenerate and nondegenerate states are a common feature when calculating corrections induced by a perturbation to degenerate states. We present an innovative mapping which simplifies these summations drastically when the perturbed problem is known to have an exact constant of the motion.
PACS: 31.15.Md – Perturbation theory / 03.65.Ge – Solutions of wave equations: bound states
© EDP Sciences, 2000