Hostname: page-component-586b7cd67f-tf8b9 Total loading time: 0 Render date: 2024-11-26T13:35:39.820Z Has data issue: false hasContentIssue false

Semi-Fredholm perturbations and commutators

Published online by Cambridge University Press:  24 October 2008

Mostafa Mbekhta
Affiliation:
Université de Lille, I, U.F.R. de Mathématiques 59655, Villeneuve d'Ascq, France

Abstract

The Laffey–West theorem concerning finite rank perturbations of bounded Fredholm operators is extended to closed densely defined operators on Banach Spaces.

Type
Research Article
Copyright
Copyright © Cambridge Philosophical Society 1993

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

REFERENCES

[1]Boulmaârouf, Z.. The Laffey–West decomposition. Proc. Roy. Irish Acad. Sect. A 88 (1988), 125131.Google Scholar
[2]Dunford, N. and Schwartz, J.. Linear Operators, vol. 1 (Wiley, 1971).Google Scholar
[3]Kato, T.. Perturbation theory for nullity, deficiency and other quantities of linear operators. J. Analyse Math. 6 (1958), 261322.CrossRefGoogle Scholar
[4]Laffey, T. J. and West, T. T.. Fredholm commutators. Proc. Roy. Irish Acad. Sect. A 82 (1982), 129140.Google Scholar
[5]Mbekhta, M.. On the generalized resolvent in Banach spaces. J. Math. Anal. Appl., submitted.Google Scholar
[6]Séarcoid, M. Ó. Economical finite rank perturbation of semi-Fredholm operators. Math. Z. 198 (1988). 431434.CrossRefGoogle Scholar
[7]Zemanek, J.. The stability radius of a semi-Fredholm operator. Integral Equations Operator Theory 8 (1985), 137144.CrossRefGoogle Scholar