Hostname: page-component-78c5997874-m6dg7 Total loading time: 0 Render date: 2024-11-05T22:26:07.231Z Has data issue: false hasContentIssue false

Singular differential operators with spectra discrete and bounded below

Published online by Cambridge University Press:  14 November 2011

Don B. Hinton
Affiliation:
Mathematics Department, University of Tennessee, Knoxville, Tennessee 37916, U.S.A.
Roger T. Lewis
Affiliation:
Mathematics Department, University of Alabama in Birmingham, Alabama 35294, U.S.A.

Synopsis

A weighted, formally self-adjoint ordinary differential operator l of order 2n is considered, and conditions are given on the coefficients of l which ensure that all self-adjoint operators associated with l have a spectrum which is discrete and bounded below. Both finite and infinite singularities are considered. The results are obtained by the establishment of certain conditions which imply that l is non-oscillatory.

Type
Research Article
Copyright
Copyright © Royal Society of Edinburgh 1979

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

1Ahlbrandt, C. D.. Equivalent boundary value problems for self-adjoint differential systems. J. Differential Equations 9 (1971), 420435.CrossRefGoogle Scholar
2Berkowitz, J.. On the discreteness of spectra of singular Sturm-Liouville problems. Comm. Pure Appl. Math. 12 (1959), 523542.CrossRefGoogle Scholar
3Dunford, N. and Schwartz, J. T.. Linear operators, II (New York: Interscience, 1963).Google Scholar
4Friedrichs, K.. Criteria for the discrete character of the spectra of ordinary differential equations. Courant Anniversary Volume (New York: Interscience, 1948).Google Scholar
5Friedrichs, K.. Criteria for discrete spectra. Comm. Pure Appl. Math. 3 (1950), 439449.CrossRefGoogle Scholar
6Glazman, I. M.. Direct methods of qualitative spectral analysis of singular differential operators (Jerusalem: I.P.S.T., 1965).Google Scholar
7Hinton, D.. Continuous spectra of an even order differential operator. Illinois J. Math. 18 (1974), 444450.CrossRefGoogle Scholar
8Hinton, D.. Limit point criteria for differential equations, II. Canad. J. Math. 26 (1974), 340351.CrossRefGoogle Scholar
9Hinton, D.. Molchanov's discrete spectra criterion for a weighted operator. Canad. Math. Bull., to appear.Google Scholar
10Hinton, D. and Lewis, R. T.. Discrete spectra criteria for singular differential operators with middle terms. Math. Proc. Camb. Phil. Soc. 77 (1975), [337347.CrossRefGoogle Scholar
11Hinton, D. and Lewis, R. T.. Oscillation theory at a finite singularity. J. Differential Equations, 30 (1978), 235247.CrossRefGoogle Scholar
12Lewis, R. T.. The discreteness of the spectrum of self-adjoint, even order, one term, differential operators. Proc. Amer. Math. Soc. 42 (1974), 480482.CrossRefGoogle Scholar
13Müller-Pfeiffer, E.. Spektraleigenschaften singulärer gewöhnlicher Differentialopemtoren (Leipzig: Teubner-Texte zur Mathematik, 1977).Google Scholar
14Naimark, M. A.. Linear differential operators: Pt II (New York: Ungar,1968).Google Scholar
15Rollins, L.. Criteria for discrete spectrum of singular self-adjoint differential operators. Proc. Amer. Math. Soc. 34 (1972), 195200.CrossRefGoogle Scholar
16. Reid, W. T.. Riccati matrix differential equations and nonoscillation criteria for associated systems. Pacific J. Math. 13 (1963), 665685.CrossRefGoogle Scholar