Partial isometries and the conjecture of C. K. Fong and S. K. Tsui

2015/11/29 by Mbekhta, Mostafa, Suciu, Laurian
#FOS: Mathematics #Functional Analysis (math.FA)

paper · doi:10.48550/arxiv.1511.09055

Abstract

We investigate some bounded linear operators T on a Hilbert space which satisfy the condition |T | less or equal to |ReT |. We describe the maximum invariant subspace for a contraction T on which T is a partial isometry to obtain that, in certain cases, the above condition ensures that T is self-adjoint. In other words we show that the Fong-Tsui conjecture holds for partial isometries, contractive quasi-isometries, or 2-quasi-isometries, and Brownian isometries of positive covariance, or even for a more general class of operators.

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