Hostname: page-component-78c5997874-j824f Total loading time: 0 Render date: 2024-11-10T20:30:05.261Z Has data issue: false hasContentIssue false

On Schrödinger's factorization method for Sturm-Liouville operators

Published online by Cambridge University Press:  14 November 2011

U.-W. Schmincke
Affiliation:
Institut für Mathematik, RWTH Aachen

Synopsis

We consider the Friedrichs extension A of a minimal Sturm-Liouville operator L0 and show that A admits a Schrödinger factorization, i.e. that one can find first order differential operators Bk with where the μk are suitable numbers which optimally chosen are just the lower eigenvalues of A (if any exist). With the help of this theorem we derive for the special case L0u = −u″ + q(x)u with q(x) → 0 (|x| → ∞) the inequality

σd(A) being the discrete spectrum of A. This inequality is seen to be sharp to some extent.

Type
Research Article
Copyright
Copyright © Royal Society of Edinburgh 1978

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1Coppel, W. A. Disconjugacy. Lecture Notes in Mathematics 220 (Berlin: Springer, 1971).Google Scholar
2Dirac, P. A. M.The principles of quantum mechanics, 4th edn (Oxford: Clarendon Press, 1958).CrossRefGoogle Scholar
3Flügge, S.Lehrbuch der theoretischen Physik, I V. Quantentheorie I. (Berlin: Springer, 1964).Google Scholar
4Glazman, I. M.Direct methods of qualitative spectral analysis of singular differential operators (Jerusalem: Israel Program for Scientific Transl., 1965).Google Scholar
5Green, H. S.Matrix mechanics (Groningen: Noordhoff, 1965).Google Scholar
6Green, H. S. and Triffet, T.Codiagonal perturbations. J. Mathematical Phys. 10 (1969), 10691089.CrossRefGoogle Scholar
7Hartman, P.Differential equations with nonoscillatory eigenfunctions. Duke Math. J. 15 (1948), 697709.CrossRefGoogle Scholar
8Hartman, P.Ordinary differential equations (New York: Wiley, 1964).Google Scholar
9Infeld, L. and Hull, T. E.The factorization method. Rev. Modem Phys. 23 (1951), 2168.CrossRefGoogle Scholar
10Jacobi, C. G. J.Zur Theorie der Variationsrechnung und der Differentialgleichungen. J. Reine Angew. Math. 17 (1837), 6882.Google Scholar
11Kato, T.Perturbation theory of linear operators (Berlin: Springer, 1976).Google Scholar
12Kreith, K. Oscillation theory. Lecture Notes in Mathematics 324 (Berlin: Springer, 1973).Google Scholar
13Kreith, K.Picone's identity and generalizations. Rend. Mat. 8 (1975), 251262.Google Scholar
14Miller, W.Lie theory and special functions (New York: Academic Press, 1968).Google Scholar
15Morse, P. M. and Feshbach, H.Methods of theoretical physics I. (New York: McGraw-Hill, 1953).Google Scholar
16Pauli, W.Über das Wasserstoffspektrum vom Standpunkt der neueren Quantenmechanik. Z. Physik 36 (1926), 336363.CrossRefGoogle Scholar
17Rellich, F.Halbbeschränkte gewöhnliche Differentialgleichungen zweiter Ordnung. Math. Ann. 122 (1951), 343368.CrossRefGoogle Scholar
18Rubinowicz, A.Sommerfelds ehe Polynommethode (Berlin: Springer, 1972).CrossRefGoogle Scholar
19Schrödinger, E.A method of determining quantum-mechanical eigenvalues and eigenfunctions. Proc. Roy. Irish Acad. Sect. A 46 (1940), 916.Google Scholar
20Schrödinger, E.Further studies on solving eigenvalue problems by factorization. Proc. Roy. Irish Acad. Sect. A 46 (1940), 183206.Google Scholar
21Schrödinger, E.The factorization of the hypergeometric equation. Proc. Roy. Irish Acad. Sect. A 47 (1941), 5354.Google Scholar
22Simon, B.The bound state of weakly coupled Schrödinger operators in one and two dimensions. Ann. Physics 97 (1976), 279288.CrossRefGoogle Scholar
23Weyl, H.Gruppentheorie und Quantenmechanik, 2nd edn (Leipzig: Hirzel, 1931).Google Scholar