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Characteristic functions of operators similar to unitary operators


Author: P. Ghatage
Journal: Proc. Amer. Math. Soc. 59 (1976), 62-64
MSC: Primary 47A45
DOI: https://doi.org/10.1090/S0002-9939-1976-0420308-X
MathSciNet review: 0420308
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Abstract: Suppose $ T$ denotes an operator which is similar to a unitary operator and $ {\theta _T}$ denotes its characteristic function--considered as an operator on $ {H^2}({D_T})$. It is proved that $ {\theta _T}$ is a bounded operator if and only if it is the inverse of a bounded operator.


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Additional Information

DOI: https://doi.org/10.1090/S0002-9939-1976-0420308-X
Keywords: Characteristic function, $ J$-unitary dilation
Article copyright: © Copyright 1976 American Mathematical Society

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