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Doubling perturbation sizes and preservation of operator indices in normed linear spaces†

Published online by Cambridge University Press:  24 October 2008

Karl Gustafson
Karl Gustafson
Affiliation:
University of Minnesota
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Abstract

We extend the index theory of Fredholm operators in Banach spaces to general operators in normed linear spaces. In so doing we make use of a doubling technique, which we also apply to obtain improved results for the perturbation of semigroups and sesquilinear forms.

Type
Research Article
Information
Mathematical Proceedings of the Cambridge Philosophical Society , Volume 66 , Issue 2 , September 1969 , pp. 281 - 294
Copyright
Copyright © Cambridge Philosophical Society 1969

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References

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