Use of Nonlinear Sequence-to-Sequence Transformations in High-Order Perturbation Theory Calculations

Abstract

The sequences of partial sums for quantities such as bound-state energies that one obtains from high-order perturbation theory often have poor convergence qualities. Here it is pointed out that use of nonlinear sequence-to-sequence transformations may dramatically improve the convergence properties of the perturbation theory results. This technique is illustrated by application to data from a recent paper.