Studies in Perturbation Theory

During the 1960s, a series of papers with the general title Studies in perturbation theory were published by P.-O. Ldwdin [42-53]. The first paper in the series appeared in the Journal of Molecular Spectroscopy in 1963 [42]. A final and 14th paper in the series was co-authored by O. Goscinski and appeared in 1971 in the International Journal of Quantum Chemistry [53]. 

Studies in Perturbation Theory. I. An Elementary Iteration-Variation Procedure for Solving the Schrodinger Equation by Partitioning technique 

Studies in Perturbation Theory. II. Generalization of the Brillouin-Wigner Formalism 

BriUouin, Le Journal de Physique et le Radium Series VII, Tome III, 373, 1932. 

Studies in Perturbation Theory. HI. Solution of the Schrddinger equation under a variation of a parameter 

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Lowdin, P-O., Studies in Perturbation Theory. X. Bounds to Energy Eigenvalues in Perturbation Theory Ground State, Physical Review, 1965 139A 357-364. 

Through 1960, Per-Olov had authored and coauthored some fifty papers. He added nearly two hundred in the following thirty-five years. These covered topics in quantum genetics, proton tunneling, and science in society in addition to further pursuits in quantum theory. The series Studies in Perturbation Theory I-XIV demonstrated a search for economy and elegance in presentation, which was important to Per-Olov and became one of his trademarks as a scientist. Per-Olov frequently referred to the economy of thinking" as shorthand for elegance... 

P.-O. Lowdin, Studies in perturbation theory. IX. Connection between various approaches in the recent development-evaluation of upper bounds to energy eigenvalues in Schrodinger s perturbation theory. J. Math. Phys. 6, 1341-1353 (1965)... 

P.-O. Lowdin. Studies in Perturbation Theory Part VIII. Separation of Dirac equation + Study of Spin-Orbit Coupling + Fermi Contact Terms. J. Mol. Spectrosc., 14(2) (1964) 131-144. 

The series of papers by Lowdin [109-121] entitled Studies in perturbation theory contributed much to our understanding of different perturbation theories and the relation between them. 

Lowdin, P-O., 8cGoscinski, O. (1999). Studies in perturbation theory. XIV. Treatment of constants of motion, degeneracies and symmetry properties by means of multidimensional partitioning. International Journal of Quantum Chemistry, 5, 685. 

During the period 1963-1971, P.-O. Lowdin published a series of papers [42-53] with the general title Studies in Perturbation Theory , which afforded deep insight into perturbation theory expansions, the relation between different expansions and their application to quantum mechanical problems. We conclude this section with a brief overview of Ldwdin s work on perturbation theory. 

Studies in Perturbation Theory. IV. Solution of Eigenvalue Problem by Projection Operator Formalism... 

Studies in Perturbation Theory. V. Some Aspects on the Exact Self-Consistent Field Theory... 

Studies in Perturbation Theory. VI. Contraction of secular equations... 

Studies in Perturbation Theory. VIII. Separation of the Dirac equation and study of the spin-orbit coupling and Fermi contact terms... 

Studies in Perturbation Theory. IX. Connection Between Various Approaches in the Recent Development - Evaluation of Upper Bounds to Energy Eigenvalues in Schrbdinger s Perturbation Theory... 

Studies in Perturbation Theory. XL Lower bounds to energy eigenvalues, ground state, and excited state... 

Studies in Perturbation Theory. XIII. Treatment of Constants of the Motion in Resolvent Method, Partitioning Technique, and Pertubation Theory... 

In this appendix, we present the titles and abstracts of Lowdin s influential series of papers under the general title Studies in Perturbation Theory . There are fourteen titles in the series, which was published between 1963 and 1971. The fourteenth paper is co-authored by O. Goscinski. 

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