Please use this identifier to cite or link to this item:
http://hdl.handle.net/10662/12285
Title: | Unitary skew-dilations of Hilbert space operators |
Authors: | Agniel, V. |
Keywords: | Hilbert space operators;Dilations;Compressions of linear operators;Functional calculi;Numerical radius;ρ-radii;ρ-classes;(ρn )-classes;Operadores espaciales de Hilbert;Dilataciones;Compresiones de operadores lineales;Cálculos funcionales;Radio numérico;Radios ρ;Clases ρ;Clases (ρn) |
Issue Date: | 2020 |
Publisher: | Universidad de Extremadura |
Abstract: | The aim of this paper is to study, for a given sequence (ρn )n≥1 of complex numbers, the class of Hilbert space operators possessing (ρn)-unitary dilations. This is the class of bounded linear operators T acting on a Hilbert space H, whose iterates Tn can be represented as Tn = ρnPHUn|H , n ≥ 1, for some unitary operator U acting on a larger Hilbert space, containing H as a closed subspace. Here PH is the projection from this larger space onto H. The case when all ρn ’s are equal to a positive real number ρ leads to the class Cρ introduced in the 1960s by Foias and Sz.-Nagy, while the case when all ρn ’s are positive real numbers has been previously considered by several authors. Some applications and examples of operators possessing (ρn)-unitary dilations, showing a behavior different from the classical case, are given in this paper. |
URI: | http://hdl.handle.net/10662/12285 |
DOI: | 10.17398/2605-5686.35.2.137 |
Appears in Collections: | Extracta Mathematicae Vol. 35, nº 2 (2020) |
Files in This Item:
File | Description | Size | Format | |
---|---|---|---|---|
2605-5686_35_2_137.pdf | 577,06 kB | Adobe PDF | View/Open |
This item is licensed under a Creative Commons License