DOI

10.1007/s13324-024-00924-z

Abstract

If U is a unitary operator on a separable complex Hilbert space H, an application of the spectral theorem says there is a conjugation C on H (an antilinear, involutive isometry on H) for which CUC= U*. In this paper, we fix a unitary operator U and describe all of the conjugations C which satisfy this property. As a consequence of our results, we show that a subspace is hyperinvariant for U if and only if it is invariant for any conjugation C for which CUC = U*.

Document Type

Article

Publication Date

5-16-2024

Publisher Statement

Copyright © 2024, Springer Link.

DOI: https://doi.org/10.1007/s13324-024-00924-z

The definitive version is available at: https://link.springer.com/article/10.1007/s13324-024-00924-z

Available for download on Saturday, April 26, 2025

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