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On the spectra of prespectral operators

Published online by Cambridge University Press:  18 May 2009

B. Nagy
B. Nagy
Affiliation:
Department of Mathematics, Technical University, Budapest, Hungary
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The spectrum of a prespectral operator was investigated by Dowson in [4]. The question was left open there whether, if a prespectral operator has closed range, the same is true for its scalar part. In this paper we answer this in the affirmative and point out some consequences concerning the essential spectra of prespectral operators. Also, following Taylor and Halberg [11], we present the state diagram of a prespectral operator, which will show, in a sense, the sharpness of the results of the spectral theory of such operators.

Type
Research Article
Information
Glasgow Mathematical Journal , Volume 19 , Issue 1 , January 1978 , pp. 57 - 61
Copyright
Copyright © Glasgow Mathematical Journal Trust 1978

References

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