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Related papers: Weighted shifts on directed trees. Their multiplie…

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We show that a weighted shift on a directed tree is related to a multiplier algebra of coefficients of analytic functions. We use this relation to study spectral properties of the operators in question.

Functional Analysis · Mathematics 2018-09-06 Piotr Budzynski , Piotr Dymek , Marek Ptak

A new class of (not necessarily bounded) operators related to (mainly infinite) directed trees is introduced and investigated. Operators in question are to be considered as a generalization of classical weighted shifts, on the one hand, and…

Functional Analysis · Mathematics 2012-03-19 Zenon Jablonski , Il Bong Jung , Jan Stochel

The weighted shifts are long known and important class of operators. One of known generalisation of this class are weighted shifts on directed trees, where we replace the linear order of coordinates in $\ell^2$ with a possibly more…

Functional Analysis · Mathematics 2022-09-21 Piotr Pikul

Assorted weighted shifts over finite rooted directed trees are studied. Their complex symmetry is characterized.

Functional Analysis · Mathematics 2025-10-23 Piotr Budzyński

Let $S_{\lambdab}$ be a bounded left-invertible weighted shift on a rootless directed tree $\mathcal T=(V, \mathcal E).$ We address the question of when $S_{\lambdab}$ has Wold-type decomposition. We relate this problem to the convergence…

Functional Analysis · Mathematics 2025-01-03 Sameer Chavan , Shailesh Trivedi

We study the dynamical behaviour of weighted shifts defined on sequence spaces of a directed tree. In particular, we characterize their boundedness as well as when they are hypercyclic, weakly mixing and mixing.

Functional Analysis · Mathematics 2021-06-29 Karl-G. Grosse-Erdmann , Dimitris Papathanasiou

We systematically develop the multivariable counterpart of the theory of weighted shifts on rooted directed trees. Capitalizing on the theory of product of directed graphs, we introduce and study the notion of multishifts on directed…

Functional Analysis · Mathematics 2016-09-13 Sameer Chavan , Deepak Kumar Pradhan , Shailesh Trivedi

A formally normal weighted shift on a directed tree is shown to be a bounded normal operator. The question of whether a normal extension of a subnormal weighted shift on a directed tree can be modeled as a weighted shift on some, possible…

Functional Analysis · Mathematics 2013-10-15 Zenon Jan Jablonski , Il Bong Jung , Jan Stochel

We study the existence of algebras of hypercyclic vectors for weighted backward shifts on sequence spaces of directed trees with the coordinatewise product. When $V$ is a rooted directed tree, we show the set of hypercyclic vectors of any…

Functional Analysis · Mathematics 2024-11-25 Arafat Abbar , Fernando Costa

In a paper from 2012 Jab{\l}o\'nski, Jung and Stochel introduced the weighted shifts on directed trees, a generalisation of well known weighted shift operators on $\ell^2$. In the last decade this class has proven itself handy for finding…

Functional Analysis · Mathematics 2024-09-26 Piotr Pikul

Criteria for subnormality of unbounded injective weighted shifts on leafless directed trees with one branching vertex are proposed. The case of classical weighted shifts is discussed. The relevance of an inductive limit approach to…

Functional Analysis · Mathematics 2013-10-15 Piotr Budzyński , Zenon Jan Jabłoński , Il Bong Jung , Jan Stochel

Let $\mathscr T$ be a rooted directed tree with finite branching index $k_{\mathscr T}$ and let $S_{\lambda} \in B(l^2(V))$ be a left-invertible weighted shift on ${\mathscr T}$. We show that $S_{\lambda}$ can be modelled as a…

Functional Analysis · Mathematics 2017-05-17 Sameer Chavan , Shailesh Trivedi

We completely characterize non-periodic balanced weighted shifts $S_{\lambdab}$ on rooted directed trees under a very mild assumption that $S_{\lambdab}^{*n}S_{\lambdab}^n|_{\ker S_{\lambdab}^*}$ is invertible operator on $\ker…

Functional Analysis · Mathematics 2025-08-04 Shubhankar Mandal , Shailesh Trivedi

Inspired by natural classes of examples, we define generalized directed semi-tree and construct weighted shifts on the generalized directed semi-trees. Given an $n$-tuple of directed directed semi-trees with certain properties, we associate…

Functional Analysis · Mathematics 2022-01-25 Gargi Ghosh , Somnath Hazra

In this paper, we introduce a discrete analogue of weighted Hardy spaces on rooted trees and study weighted composition operators between them in detail. In particular, we characterize bounded and compact weighted composition operators…

Functional Analysis · Mathematics 2021-12-16 P. Muthukumar , Ajay K. Sharma , Vivek Kumar

In this paper we investigate a new class of operators called weighted shifts on directed trees introduced recently in [Z. J. Jablonski, I. B. Jung and J. Stochel, A Non-hyponormal Operator Generating Stieltjes Moment Sequences, J. Funct.…

Functional Analysis · Mathematics 2016-04-05 György Pál Gehér

Centered weighted composition operators on $L^2$-spaces are characterized. The characterization is obtained without the assumption that the operator is a product of a multiplication and a composition operator. The concept of spectrally…

Functional Analysis · Mathematics 2026-04-20 Piotr Budzyński

It is shown that for every positive integer $n$ there exists a subnormal weighted shift on a directed tree (with or without root) whose $n$th power is densely defined while its $(n+1)$th power is not. As a consequence, for every positive…

Functional Analysis · Mathematics 2013-09-04 Piotr Budzynski , Piotr Dymek , Zenon Jan Jablonski , Jan Stochel

This paper explores the notions of $\mathcal{F}$-transitivity and topological $\mathcal{F}$-recurrence for backward shift operators on weighted $\ell^p$-spaces and $c_0$-spaces on directed trees, where $\mathcal{F}$ represents a Furstenberg…

Functional Analysis · Mathematics 2026-03-04 Evgeny Abakumov , Arafat Abbar

Weighted shifts on directed trees are a decade old generalisation of classical shift operators in the sequence space $\ell^2$. In this paper we introduce the joint backward extension property (JBEP) for classes of weighted shifts on…

Functional Analysis · Mathematics 2022-10-17 Piotr Pikul
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