1993/06/23 by K. Suzuki, R. Okamoto, P.J. Ellis +3 · 3 citations
Computer Science · Mathematics · Physics and Astronomy · #Matrix Theory and Algorithms #Model Reduction and Neural Networks #Numerical methods for differential equations #nucl-th
paper · pdf · doi:10.1016/0375-9474(94)90025-6
published as Nucl.Phys. A567 (1994) 576-590 · Latex, 23 pages, 4 figures (postscript, available from authors), Minnesota preprint NUC-MINN-93/11-T
arxiv created 1993/06/23 · openalex publication_date 1994/01/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We generalize the Lee-Suzuki iteration method for summing the folded diagram series to the case where the unperturbed model-space energies are non-degenerate. A condition is derived for the convergence of the iteration scheme and this depends on the choice of the model space projection operators. Two choices are examined, in the first the projection operators are defined in terms of the unperturbed states and in the second they are defined in terms of the eigenfunctions obtained at each stage of the iteration. As is illustrated by calculations with a simple model, the second procedure gives the better convergence and, by suitable choice of the starting energies, allows the reproduction of any subset of the exact eigenvalues.