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Related papers: Two-Variable Compressions of Shifts, Toeplitz Oper…

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We prove that the closure of the numerical range of a $(n+1)$-periodic and $(2m+1)$-banded Toeplitz operator can be expressed as the closure of the convex hull of the uncountable union of numerical ranges of certain symbol matrices. In…

Functional Analysis · Mathematics 2026-01-14 Benjamín A. Itzá-Ortiz , Rubén A. Martínez-Avendaño , Hiroshi Nakazato

We extend results on compressed Toeplitz operators on the backward shift invariant subspaces of $H^2 $ to the context of the spaces $H^p$, $1<p<\infty.$

Complex Variables · Mathematics 2019-08-06 Maria Nowak , Andrzej Soltysiak

This paper studies the \(k^{th}-\)order slant Toeplitz and slant little Hankel operators on the weighted Bergman space \(\mathcal{A}_\alpha^2(\mathbb{D})\). These operators are constructed using a slant shift operator \(W_k\) composed with…

Functional Analysis · Mathematics 2025-07-10 Oinam Nilbir Singh , M. P. Singh , Thokchom Sonamani Singh

Rational inner functions are a generalization of finite Blaschke products to several variables. In this article we survey a variety of results about rational inner functions related to interpolation, sums of squares formulas, and boundary…

Functional Analysis · Mathematics 2025-02-20 Greg Knese

Replacing operators with continuous operator-valued functions, we prove time-dependent versions of well-known results on compressions and diagonals of bounded operators. The setting of smooth functions is also addressed. Our results have no…

Functional Analysis · Mathematics 2025-12-18 Vladimir Müller , Yuri Tomilov

This paper gives a new approach to the calculation of the numerical radius of a restricted shift operator by linking it to the norm of a truncated Toeplitz operator (TTO), which can be be calculated by various methods. Further results on…

Functional Analysis · Mathematics 2019-05-17 Pamela Gorkin , Jonathan R. Partington

A truncated Toeplitz operator is the compression $A_{\phi}:\K_{\Theta} \to \K_{\Theta}$ of a Toeplitz operator $T_{\phi}:H^2\to H^2$ to a model space $\K_{\Theta} := H^2 \ominus \Theta H^2$. For $\Theta$ inner, let $\T_{\Theta}$ denote the…

Functional Analysis · Mathematics 2009-10-03 Joseph A. Cima , Stephan Ramon Garcia , William T. Ross , Warren R. Wogen

A Toeplitz operator $T_\varphi$, $\varphi \in L^\infty(\mathbb{T}^n)$, is a partial isometry if and only if there exist inner functions $\varphi_1, \varphi_2 \in H^\infty(\mathbb{D}^n)$ such that $\varphi_1$ and $\varphi_2$ depends on…

Functional Analysis · Mathematics 2022-02-08 Deepak K. D , Deepak Pradhan , Jaydeb Sarkar

For any given bounded symmetric domain, we prove the existence of commutative $C^*$-algebras generated by Toeplitz operators acting on any weighted Bergman space. The symbols of the Toeplitz operators that generate such algebras are defined…

Operator Algebras · Mathematics 2014-07-10 Matthew Dawson , Gestur Ólafsson , Raúl Quiroga-Barranco

We study algebraic properties of Toeplitz operators on Bergman spaces of polyanalytic functions on the unit disk. We obtain results on finite-rank commutators and semi-commutators of Toeplitz operators with harmonic symbols. We also raise…

Functional Analysis · Mathematics 2014-02-26 Zeljko Cuckovic , Trieu Le

Matrix valued inner functions on the bidisk have a number of natural subspaces of the Hardy space on the torus associated to them. We study their relationship to Agler decompositions, regularity up to the boundary, and restriction maps into…

Functional Analysis · Mathematics 2017-01-20 Kelly Bickel , Greg Knese

We define positive Toeplitz operators between weighted harmonic Bloch spaces $b^\infty_\alpha$ on the unit ball of $\mathbb{R}^n$ for the full range of parameter $\alpha\in\mathbb{R}$. We give characterizations of bounded and compact…

Complex Variables · Mathematics 2023-05-22 Ömer Faruk Doğan

We develop a Clark theory for commuting compressed shift operators on model spaces $K_{\phi}$ associated with inner functions $\phi$ on the bidisk, which exhibits both similarities and marked differences compared to the classical…

Complex Variables · Mathematics 2026-05-18 Palak Arora , Kelly Bickel , Constanze Liaw , Alan Sola

The symmetrized bidisc has been a rich field of holomorphic function theory and operator theory. A certain well-known reproducing kernel Hilbert space of holomorphic functions on the symmetrized bidisc resembles the Hardy space of the unit…

Functional Analysis · Mathematics 2020-03-23 Tirthankar Bhattacharyya , B. Krishna Das , Haripada Sau

In this paper we are concerned with hyponormality and subnormality of block Toeplitz operators acting on the vector-valued Hardy space $H^2_{\mathbb{C}^n}$ of the unit circle. Firstly, we establish a tractable and explicit criterion on the…

Functional Analysis · Mathematics 2012-07-16 Raul Curto , In Sung Hwang , Woo Young Lee

Given a polyanalytic function, we show that the corresponding Toeplitz operator on the Bergman space of the unit disc can be expressed as a quotient of certain differential operators with holomorphic coefficients. This enables us to obtain…

Functional Analysis · Mathematics 2018-12-27 Akaki Tikaradze

We analyze the fine structure of Clark measures and Clark isometries associated with two-variable rational inner functions on the bidisk. In the degree (n,1) case, we give a complete description of supports and weights for both generic and…

Functional Analysis · Mathematics 2023-12-12 Kelly Bickel , Joseph A. Cima , Alan A. Sola

Suppose that $\phi$ and $\psi$ are smooth complex-valued functions on the circle that are invertible, have winding number zero with respect to the origin, and have meromorphic extensions to an open neighborhood of the closed unit disk. Let…

Functional Analysis · Mathematics 2010-01-19 Efton Park

For an inner function u we discuss the dual operator for the well-known compressed shift. We establish conditions for two dual compressed shifts to be unitarily equivalent/similar and we describe the invariant subspace structure for the…

Functional Analysis · Mathematics 2020-04-15 M. C. Camara , W. T. Ross

We discuss an extension of Toeplitz quantization based on polyanalytic functions. We derive isomorphism theorem for polyanalytic Toeplitz operators between weighted Sobolev-Fock spaces of polyanalytic functions, which are images of…

Mathematical Physics · Physics 2019-12-12 Johannes Keller , Franz Luef