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Related papers: Normaloid Weighted Composition Operators on $H^2$

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We study the approximation numbers of weighted composition operators $f\mapsto w\cdot(f\circ\varphi)$ on the Hardy space $H^2$ on the unit disc. For general classes of such operators, upper and lower bounds on their approximation numbers…

Functional Analysis · Mathematics 2017-12-27 Gandalf Lechner , Daniel Li , Hervé Queffélec , Luis Rodríguez-Piazza

We obtain a complete description of semi-Fredholm spectra of operators of the form $(Tf)(z) = w(z)f(B(z)$ acting on the disc algebra in the case when $B$ is either elliptic or double parabolic finite Blaschke product of degree $d \geq 2$…

Spectral Theory · Mathematics 2025-05-13 Arkady Kitover , Mehmet Orhon

Let $u$ be a holomorphic function and $\varphi$ a holomorphic self-map of the open unit disk $\mathbb{D}$ in the complex plane. We give some new characterizations for the boundedness of the weighted composition operators $uC_{\varphi}$ from…

Functional Analysis · Mathematics 2014-01-03 Yu-Xia Liang , Ze-Hua Zhou

We study weighted composition operators on Hilbert spaces of analytic functions on the unit ball with kernels of the form $(1-<z,w>)^{-\gamma}$ for $\gamma>0$. We find necessary and sufficient conditions for the adjoint of a weighted…

Functional Analysis · Mathematics 2012-07-26 Trieu Le

In this paper, we consider \emph{unbounded} weighted composition operators acting on Fock space, and investigate some important properties of these operators, such as $\calC$-selfadjoint (with respect to weighted composition conjugations),…

Complex Variables · Mathematics 2018-11-27 Pham Viet Hai

Let $\mathbb{D}$ denote the unit disk of $\mathbb{C}$ and let $\Lambda^\alpha(\mathbb{D})$ denote the scale of holomorphic Lipschitz spaces extended to all $\alpha\in\mathbb{R}$. For arbitrary $\alpha, \beta\in\mathbb{R}$, we characterize…

Complex Variables · Mathematics 2017-11-07 Evgueni Doubtsov

We study the strong continuity of weighted composition semigroups of the form $T_tf=\varphi_t'\left(f\circ\varphi_t\right)$ in several spaces of analytic functions. First we give a general result on separable spaces and use it to prove that…

Functional Analysis · Mathematics 2017-06-29 Irina Arévalo , Marcos Oliva

In this note, we completely characterize complex symmetric weighted composition differentiation operator on the Hardy space $H^2$ with respect to the conjugation operator $C_{\lambda,\alpha}$. Meanwhile, the normal and self-adjoint of the…

Functional Analysis · Mathematics 2020-11-17 Junming Liu , Saminathan Ponnusamy , Huayou Xie

We study composition operators on the Fock spaces $\mathcal{F}^2_\alpha(\mathbb{C}^n)$, problems considered include the essential norm, normality, spectra, cyclicity and membership in the Schatten classes. We give perfect answers for these…

Complex Variables · Mathematics 2016-08-23 Liangying Jiang , Gabriel T. Prajitura , Ruhan Zhao

We use induction and interpolation techniques to prove that a composition operator induced by a map $\phi$ is bounded on the weighted Bergman space $\A^2_\alpha(\mathbb{H})$ of the right half-plane if and only if $\phi$ fixes $\infty$…

Functional Analysis · Mathematics 2009-10-05 Sam Elliott , Andrew Wynn

We prove that the norm of a weighted composition operator on the Hardy space H^2 of the disk is controlled by the norm of the weight function in the de Branges-Rovnyak space associated to the symbol of the composition operator. As a…

Functional Analysis · Mathematics 2007-07-24 Michael T. Jury

In this paper, we explore the complex symmetrical characteristics of weighted composition operators $W_{u, v}$ and weighted composition-differentiation operators $W_{u, v, k_1, k_2, \ldots, k_n}$ on the Hardy space $H^2(\mathbb{D}^n)$ over…

Functional Analysis · Mathematics 2023-12-05 Molla Basir Ahamed , Vasudevarao Allu , Taimur Rahman

A complete characterisation is given of all the linear isometries of the Fr\'echet space of all holomorphic functions on the unit disc, when it is given one of the two standard metrics: these turn out to be weighted composition operators of…

Complex Variables · Mathematics 2024-05-17 I. Chalendar , L. Oger , J. R. Partington

In the present paper, we study the composition operators acting on weighted Hardy spaces of polynomial growth, which are concerned with norms, spectra and (semi-)Fredholmness. Firstly, we estimate the norms of the composition operators with…

Functional Analysis · Mathematics 2023-02-17 Bingzhe Hou , Chunlan Jiang

We prove that a composition operator is bounded on the Hardy space $H^2$ of the right half-plane if and only if the inducing map fixes the point at infinity non-tangentially, and has a finite angular derivative $\lambda$ there. In this case…

Functional Analysis · Mathematics 2014-02-26 Sam Elliott , Michael T. Jury

Let $\phi$ be an analytic self-map and $u$ be a fixed analytic function on the open unit disk $D$ in the complex plane $\CC.$ The weighted composition operator is defined\break by \begin{equation*} uC_\phi f =u \cdot (f\circ \phi), f \in…

Complex Variables · Mathematics 2007-09-24 Songxiao Li , Stevo Stević

In this paper, we investigate the complex symmetric structure of generalized weighted composition operators $D_{m,\psi,\varphi}$ on the weighted Hardy space $H^2(\beta)$. We obtain explicit conditions for $ D_{m,\psi,\varphi}$ to be complex…

Functional Analysis · Mathematics 2022-04-25 Lian Hu , Songxiao Li , Rong Yang

We consider composition operators $\mathscr{C}_\varphi$ on the Hardy space of Dirichlet series $\mathscr{H}^2$, generated by Dirichlet series symbols $\varphi$. We prove two different subordination principles for such operators. One…

Functional Analysis · Mathematics 2019-11-13 Ole Fredrik Brevig , Karl-Mikael Perfekt

In the context of analytic functions on the open unit disk, a weighted composition operator is simply a composition operator followed by a multiplication operator. The class of weighted composition operators has an important place in the…

Functional Analysis · Mathematics 2012-04-10 Peter C. Gibson , Mohammad S. Tavalla

We realize norms of most composition operators acting on the Hardy space with linear fractional symbol as roots of hypergeometric functions. This realization leads to simple necessary and sufficient conditions on the symbol to exhibit…

Complex Variables · Mathematics 2007-05-23 Estelle L. Basor , Dylan Q. Retsek