Hostname: page-component-84b7d79bbc-dwq4g Total loading time: 0 Render date: 2024-07-29T11:24:30.713Z Has data issue: false hasContentIssue false

m (λ)-functions for complex Sturm-Liouville operators

Published online by Cambridge University Press:  14 November 2011

David Race
Affiliation:
Department of Mathematics, University of the Witwatersrand, 1 Jan Smuts Avenue, Johannesburg 2001, South Africa

Synopsis

In this paper, the formally J-symmetric Sturm-Liouville operator with complex-valued coefficients is considered and a generalisation of the Weyl limit-point, limit-circle dichotomy is sought by means of m (λ )-functions. These functions are then used to give an explicit description of all the associated J-selfadjoint operators with separated boundary conditions in the limit-circle case. A formulation of the eigenvalues of these operators, and a characterisation of which extensions are non-well-posed, are also found. Finally, the limit-point case is studied, mainly by means of an example.

Type
Research Article
Copyright
Copyright © Royal Society of Edinburgh 1980

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

1Fulton, C. T.. Parametrizations of Titchmarsh's m (λ)-functions in the limit circle case. Trans. Amer. Math. Soc. 229 (1977), 5163.Google Scholar
2Hartman, P.. Ordinary differential equations (New York: Wiley, 1964).Google Scholar
3Knowles, I. W.. Symmetric conjugate-linear operators in Hilbert space, pre-print.Google Scholar
4Knowles, I. W. and Race, D.. On the point-spectra of complex Sturm-Liouville operators. Proc. Roy. Soc. Edinburgh Sect. A 85 (1980), 263290.Google Scholar
5Race, D.. On the location of the essential spectra and regularity fields of complex Sturm-Liouville operators. Proc. Roy. Soc. Edinburgh Sect. A 85 (1979), 114.Google Scholar
6Race, D.. The spectral theory of complex Sturm-Liouville operators (Ph.D. thesis, Univ. of the Witwatersrand, Johannesburg, 1979).Google Scholar
7Sims, A. R.. Secondary conditions for linear differential operators of the second order. J. Math. Mech. 6 (1957), 247285.Google Scholar
8Titchmarsh, E. C.. Eigenfunetion expansions associated with second-order differential equations 2nd edn, vol. I (Oxford: Clarendon 1962).Google Scholar
9Weyl, H.. Über gewöhnliche Differentialgleichungen mit Singularitäten und die zugehörigen Entwicklungen willkürlicher Funktionen. Math. Ann. 68 (1910), 220269.CrossRefGoogle Scholar