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Related papers: Compact differences of composition operators

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In this paper, we give some estimates for the norm and essential norm of the differences of two composition operators between different Hardy spaces.

Complex Variables · Mathematics 2017-12-18 Yecheng Shi , Songxiao Li

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 article, we completely characterize the positive expansive and absolutely Ces\`aro composition operators $C_{\phi}f=f\circ \phi$ induced by affine self-maps $\phi$ of the right half-plane $\mathbb{C}_+$ on the weighted Bergman space…

Functional Analysis · Mathematics 2026-02-10 Artur Blois , Osmar R. Severiano

A classical result of Calkin [Ann. of Math. (2) 42 (1941), pp. 839-873] says that an inner derivation $S\mapsto [T,S] = TS-ST$ maps the algebra of bounded operators on a Hilbert space into the ideal of compact operators if and only if $T$…

Functional Analysis · Mathematics 2025-03-24 H. Arroussi , C. Tong , J. A. Virtanen , Z. Yuan

We discuss the compactness of Hankel operators on Hardy, Bergman and Fock spaces with focus on the differences between the three cases, and complete the theory of compact Hankel operators with bounded symbols on the latter two spaces with…

Functional Analysis · Mathematics 2020-11-11 Raffael Hagger , Jani Virtanen

We characterize the compactness of composition operators; in term of generalized Nevanlinna counting functions, on a large class of Hilbert spaces of analytic functions, which can be viewed between the Bergman and the Dirichlet spaces

Functional Analysis · Mathematics 2010-05-02 Karim Kellay , Pascal Lefèvre

In this article, we consider the following fractional {Hardy-type} inequality: \begin{align} \label{Fractional Hardy_abst} \int_{\mathbb{R}^N} |w(x)||u(x)|^p \mathrm{d}x \leq C \int_{\mathbb{R}^N \times \mathbb{R}^N}…

Analysis of PDEs · Mathematics 2025-01-17 Ujjal Das , Rohit Kumar , Abhishek Sarkar

A bounded linear operator $T$ on a separable complex Hilbert space $H$ is called $C$-normal if there is a conjugation $C$ on $H$ such that $ CT^\ast TC=TT^\ast$. Let $\varphi$ be a linear fractional self-map of $\mathbb{D}$. In this paper,…

Complex Variables · Mathematics 2022-04-18 Lian Hu , Songxiao Li , Rong Yang

We construct a compactification of the moduli space of twisted holomorphic maps with varying complex structure and bounded energy. For a given compact symplectic manifold $X$ with a compatible complex structure and a Hamiltonian action of…

Symplectic Geometry · Mathematics 2007-05-23 Ignasi Mundet i Riera , Gang Tian

In this note we study the problem of determining the holomorphic self maps of the unit disc that induce a bounded composition operator on Dirichlet-type spaces. We find a class of symbols $\varphi$ that induce a bounded composition operator…

Complex Variables · Mathematics 2025-02-19 Athanasios Beslikas

Let $\varphi\in C^0 \cap W^{1,2}(\Sigma, X)$ where $\Sigma$ is a compact Riemann surface, $X$ is a compact locally CAT(1) space, and $W^{1,2}(\Sigma,X)$ is defined as in Korevaar-Schoen. We use the technique of harmonic replacement to prove…

Differential Geometry · Mathematics 2017-01-11 Christine Breiner , Ailana Fraser , Lan-Hsuan Huang , Chikako Mese , Pam Sargent , Yingying Zhang

Let $\mathbb{D}^n$ be the polydisk in $\mathbb{C}^n$ and the symbols $\phi,\psi\in C(\bar{\mathbb{D}^n})$ such that $\phi$ and $\psi$ are pluriharmonic on any $(n-1)$-dimensional polydisk in the boundary of $\mathbb{D}^{n}.$ Then…

Functional Analysis · Mathematics 2021-03-08 Zeljko Cuckovic , Sonmez Sahutoglu

We derive a necessary condition for compactness of the weighted $\overline\partial$-Neumann operator on the space $L^2(\mathbb C^n,e^{-\varphi})$, under the assumption that the corresponding weighted Bergman space of entire functions has…

Complex Variables · Mathematics 2019-07-17 Franz Berger , Friedrich Haslinger

The framework of the paper is that of the full Fock space ${\Cal F}^2({\Cal H}_n)$ and the Banach algebra $F^\infty$ which can be viewed as non-commutative analogues of the Hardy spaces $H^2$ and $H^\infty$ respectively. An inner-outer…

Functional Analysis · Mathematics 2016-09-06 Alvaro Arias , Gelu Popescu

In this paper, we obtain a complete characterization for the compact difference of two composition operators acting on Bergman spaces with a rapidly decreasing weight $\omega=e^{-\eta}$, $\Delta\eta>0$. In addition, we provide simple…

Functional Analysis · Mathematics 2024-07-23 Inyoung Park

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

In this paper, we study the basic properties such as boundedness and compactness of composition operators on discrete analogue of generalized Hardy space defined on a homogeneous rooted tree. Also, we compute the operator norm of…

Functional Analysis · Mathematics 2016-10-03 Perumal Muthukumar , Saminathan Ponnusamy

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

This paper studies the behaviour of iterates of weighted composition operators acting on spaces of analytic functions, with particular emphasis on the Hardy space $H^2$. Questions relating to uniform, strong and weak convergence are…

Functional Analysis · Mathematics 2020-02-11 I. Chalendar , J. R. Partington

We found several new equivalent characterizations for the boundedness and compactness of the differences of weighted differentiation composition operators from Bloch-type space to weighted-type space. Especially, we estimated its essential…

Functional Analysis · Mathematics 2016-10-07 Yu-Xia Liang