Conditions on an operator implying $\textrm {Re} \sigma (T)=\sigma (\textrm {Re} T)$
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- by S. K. Berberian PDF
- Trans. Amer. Math. Soc. 154 (1971), 267-272 Request permission
Abstract:
It is shown that the equation of the title is valid for certain classes of not necessarily normal operators (including Toeplitz operators, and operators whose spectrum is a spectral set), and a new proof is given of C. R. Putnam’s theorem that it is valid for seminormal operators.References
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Additional Information
- © Copyright 1971 American Mathematical Society
- Journal: Trans. Amer. Math. Soc. 154 (1971), 267-272
- MSC: Primary 47.30
- DOI: https://doi.org/10.1090/S0002-9947-1971-0270185-5
- MathSciNet review: 0270185