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On the boundary spectrum in banach algebras

Published online by Cambridge University Press:  17 April 2009

S. Mouton
Affiliation:
Department of Mathematical Sciences, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa e-mail: [email protected]
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We investigate some properties of the set S(a) = {λ ∈ ℂ: λ – a ∈ ∂S} (which we call the boundary spectrum of a) where ∂S denotes the topological boundary of the set S of all non-invertible elements of a Banach algebra A, and where a is an element of A.

Type
Research Article
Copyright
Copyright © Australian Mathematical Society 2006

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