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Related papers: The Wold-type decomposition for $m$-isometries

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This work establishes a multivariable Wold-type decomposition for left-inverse commuting $n$-tuples of bounded operators, built on the hypothesis that each component admits a Wold-type decomposition. For pairs of operators, we obtain a…

Functional Analysis · Mathematics 2025-11-26 Monojit Bhattacharjee , Rajeev Gupta , Vidhya Venugopal

Corresponding to any $(m-1)$-tuple of semi-spectral measures on the unit circle, a weighted Dirichlet-type space is introduced and studied. We prove that the operator of multiplication by the coordinate function on these weighted…

Functional Analysis · Mathematics 2022-07-07 S. Ghara , R. Gupta , Md. R. Reza

The aim of this paper is to investigate $m$--isometric composition operators on directed graphs with one circuit. We establish a characterization of $m$--isometries and prove that complete hyperexpansiveness coincides with $2$--isometricity…

Functional Analysis · Mathematics 2020-12-15 Zenon Jan Jabłoński , Jakub Kośmider

In this article, we prove that any pair of doubly commuting $2$-isometries on a Hilbert space has a Wold-type decomposition. Moreover, the analytic part of the pair is unitary equivalent to the pair of multiplication by coordinate function…

Functional Analysis · Mathematics 2025-03-24 Monojit Bhattacharjee , Rajeev Gupta , Vidhya Venugopal

There are considered isometries on a Hilbert space. By the Wold theorem any isometry can be decomposed into a unitary operator and a unilateral shift. For a pair of isometries, even commuting, a maximal subspace reducing one isometry to a…

Functional Analysis · Mathematics 2013-01-01 Zbigniew Burdak , Marek Kosiek , Marek Słociński

Let $H_m(\mathbb B)$ be the analytic functional Hilbert space on the unit ball $\mathbb B \subset \mathbb C^n$ with reproducing kernel $K_m(z,w) = (1 - \langle z,w \rangle)^{-m}$. Using algebraic operator identities we characterize those…

Functional Analysis · Mathematics 2018-01-24 Jörg Eschmeier , Sebastian Langendörfer

We obtain a necessary and sufficient condition for a weighted composition operator to be co-isometric on a general weighted Hardy space of analytic functions in the unit disk whose reproducing kernel has the usual natural form. This turns…

Complex Variables · Mathematics 2021-07-14 María J. Martín , Alejandro Mas , Dragan Vukotić

The aim of this paper is to study $ m $-isometric weighted shifts with operator weights (both unilateral and bilateral). We obtain a characterization of such shifts by polynomials with operator coefficients. The procedure of construction of…

Functional Analysis · Mathematics 2025-03-04 Michał Buchała

This paper presents Wold-type decomposition for various pairs of twisted contractions on Hilbert spaces. As a consequence, we obtain Wold-type decomposition for pairs of doubly twisted isometries and in particular, new and simple proof of…

Functional Analysis · Mathematics 2024-04-11 Satyabrata Majee , Amit Maji

In Bergman and Dirichlet spaces, the shift operator is not an isometry, but it is a left invertible operator. In this paper we give conditions on the left invertible operators such that a operator version, in the sense of Rosenblum and…

Functional Analysis · Mathematics 2017-04-14 Laura Gavruta

In this paper, we obtain a complete description of the class of n-tuples (n >= 2) of doubly commuting isometries. In particular, we present a several variables analogue of the Wold decomposition for isometries on Hilbert spaces. Our main…

Functional Analysis · Mathematics 2013-12-13 Jaydeb Sarkar

We introduce and study doubly twisted near-isometries. A doubly twisted near-isometry is a tuple of near-isometries satisfying certain relations determined by a prescribed family of unitaries, thereby generalizing the notion of doubly…

Functional Analysis · Mathematics 2026-05-07 Sneh Lata , Santosh Singh Negi , Dinesh Singh

The unitary equivalence of $2$-isometric operators satisfying the so-called kernel condition is characterized. It relies on a model for such operators built on operator valued unilateral weighted shifts and on a characterization of the…

Functional Analysis · Mathematics 2018-06-11 Akash Anand , Sameer Chavan , Zenon Jan Jabłoński , Jan Stochel

In this paper, we discuss k-quasi-m-isometric composition operators and weighted composition operators on directed graphs with one circuit and more than one branching vertex.

Functional Analysis · Mathematics 2024-10-10 V. Devadas , E. Shine Lal , T. Prasad

In this paper we investigate composition operators on discrete spaces. We establish the classification of underlying graphs of such operators. For one class of such graphs, namely graphs with one cycle, we obtain a characterization of…

Functional Analysis · Mathematics 2024-07-30 Michał Buchała

In this paper we characterize $m$-isometric and quasi-$m$-isometric weighted composition operators on the Hilbert space $L^2(\mu)$. Also, we find that normal-$m$-isometry and normal quasi-$m$-isometry weighted composition operators have…

Functional Analysis · Mathematics 2025-09-25 M. S. Al Ghafri , Y. Estaremi , M. Z. Gashti

In this paper, we discuss k-quasi-m-isometric completion problem of unilateral weighted shifts and composition operators on directed graphs with one circuit and more than one branching vertex.

Functional Analysis · Mathematics 2026-01-29 V. Devadas , T. Prasad , E. Shine Lal

S{\l}oci\'nski gave sufficient conditions for commuting isometries to have a nice Wold-like decomposition. In this note we provide analogous results for row-isometries satisfying certain commutation relations. Other than known results for…

Functional Analysis · Mathematics 2022-03-15 Adam H. Fuller

We establish a Wold-type decomposition for isometric and isometric Nica-covariant representations of the odometer semigroup. These generalize the Wold-type decomposition for commuting pairs of isometries due to Popovici and for pairs of…

Operator Algebras · Mathematics 2021-08-10 Boyu Li

In this paper we characterize $m$-isometric and quasi-$m$-isometric weighted conditional type (WCT) operators on the Hilbert space $L^2(\mu)$. Also, we prove that the subclasses of $m$-isometric and quasi-$m$-isometric of normal WCT…

Functional Analysis · Mathematics 2025-09-30 Y. Estaremi , M. S. Al Ghafri , S. Shamsigamchi
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