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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

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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