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Related papers: A note on composition operators in a half-plane

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In this paper the necessary and sufficient conditions for the product of composition operators to be isometry are obtained on weighted Bergman space. With the help of a counter example we also proved that unlike on…

Functional Analysis · Mathematics 2021-07-07 Anuradha Gupta , Geeta Yadav

Let $\phi$ be a holomorphic self-map of the open unit disk $\mathbb{D}.$ In this article, we study the shadowing phenomenon for composition operators $C_{\phi}f=f\circ \phi$ on the Hardy space $H^2(\mathbb{D}).$ We mainly characterize all…

Dynamical Systems · Mathematics 2026-03-12 Artur Blois , Ben-Hur Eidt , Paulo Lupatini , Osmar R. Severiano

Let $\phi$ be an analytic map taking the unit disk $\mathbb{D}$ into itself. We establish that the class of composition operators $f \mapsto C_\phi(f) = f \circ \phi$ exhibits a rather strong rigidity of non-compact behaviour on the Hardy…

Functional Analysis · Mathematics 2017-10-05 Jussi Laitila , Pekka J. Nieminen , Eero Saksman , Hans-Olav Tylli

In this paper we propose a different (and equivalent) norm on $S^{2} ({\mathbb{D}})$ which consists of functions whose derivatives are in the Hardy space of unit disk. The reproducing kernel of $S^{2}({\mathbb{D}})$ in this norm admits an…

Functional Analysis · Mathematics 2018-08-31 Caixing Gu , Shuaibing Luo

Let $C_\varphi$ be a composition operator acting on the Hardy space of the unit disc $H^p$ ($1\leq p < \infty$), which is embedded in a $C_0$-semigroup of composition operators $\mathcal{T}=(C_{\varphi_t})_{t\geq 0}.$ We investigate whether…

Functional Analysis · Mathematics 2024-06-28 F. Javier González-Doña

Let $\varphi$ be a holomorphic self-map of a bounded homogeneous domain $D$ in $\mathbb{C}^n$. In this work, we show that the composition operator $C_\varphi: f\mapsto f\circ \varphi$ is bounded on the Bloch space $\mathcal{B}$ of the…

Functional Analysis · Mathematics 2022-07-27 Robert F. Allen , Flavia Colonna

Let $\varphi$ be a linear fractional self-map of the open unit disk $\mathbb{D}$ and $H^2$ the Hardy space of analytic functions on $\mathbb{D}$. The goal of this article is to characterize the linear fractional composition operators…

Functional Analysis · Mathematics 2018-09-26 S. Waleed Noor

Given two metric spaces $M$ and $N$ we study, motivated by a question of N. Weaver, conditions under which an isometric composition operator $C_\phi:\mathrm{Lip}_0(M)\longrightarrow \mathrm{Lip}_0(N)$ is isometric depending on the…

Functional Analysis · Mathematics 2019-10-18 Abraham Rueda Zoca

In this paper we will show how the boundedness condition for the weighted composition operators on a class of spaces of analytic functions on the open right complex half-plane called Zen spaces (which include the Hardy spaces and weighted…

Functional Analysis · Mathematics 2017-02-09 Andrzej S. Kucik

This paper considers composition operators on Zen spaces (a class of weighted Bergman spaces of the right half-plane related to weighted function spaces on the positive half-line by means of the Laplace transform). Generalizations are given…

Functional Analysis · Mathematics 2023-04-03 I. Chalendar , J. R. Partington

This paper aims to study the boundedness and compactness of composition operators from model spaces to the Hardy Hilbert spaces in the upper half-plane. Consequently, we investigate the boundedness and compactness of composition operators…

Functional Analysis · Mathematics 2026-05-13 Bharti Garg , Subhankar Mahapatra , Santanu Sarkar

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 study the boundedness of composition operators on the bidisk using reproducing kernels. We show that a composition operator is bounded on the Hardy space of the bidisk if some associated function is a positive kernel. This positivity…

Complex Variables · Mathematics 2018-07-02 Cheng Chu

We study the boundedness of composition operators on the weighted Bergman spaces and the Hardy space over the polydisc. For arbitrary polydisc we prove the rank sufficiency theorem which, in particular, provides us with a simple criterion…

Complex Variables · Mathematics 2022-06-30 Lukasz Kosinski

V. Matache (J. Operator Theory 73(1):243--264, 2015) raised an open problem about characterizing composition operators $C_{\phi}$ on the Hardy space $H^2$ and nonzero singular measures $\mu_1$, $\mu_2$ on the unit circle such that…

Functional Analysis · Mathematics 2024-08-20 V. A. Anjali , P. Muthukumar , P. Shankar

In this paper, we investigate weighted composition, Volterra and Integral operators on second derivative Hardy spaces. Some equivalent conditions for boundedness of the operators will be given using the boundedness on the Hardy spaces. Also…

Functional Analysis · Mathematics 2022-10-13 Mostafa Hassanlou , Ebrahim Abbasi

This paper investigates composition operators and weighted composition operators on semi-Hilbert spaces induced by positive multiplication operators on \( L^2(\mu) \). Within the framework of \( A \)-adjoint operators, we characterize…

Functional Analysis · Mathematics 2025-08-08 Y. Estaremi , M. S. Al Ghafri

This paper is devoted to the study of semigroups of composition operators and semigroups of holomorphic mappings. We establish conditions under which these semigroups can be extended in their parameter to sector given a priori. We show that…

Complex Variables · Mathematics 2015-11-17 Mark Elin , Fiana Jacobzon

In this paper we study the self-adjoint and co-isometry composition and weighted composition operator on $H_E(\zeta).$ We also discuss the conditions under which adjoint operator of a composition and weighted composition operator on…

Functional Analysis · Mathematics 2021-10-11 Anuradha Gupta , Geeta Yadav

In this paper, we study composition operators on Hilbert space of complex-valued harmonic functions. In particular, we explore isometries, the type of self-map that generate bounded composition operator, and characterize the boundedness of…

Functional Analysis · Mathematics 2025-03-14 Tseganesh Getachew Gebrehana , Hunduma Legesse Geleta