English
Related papers

Related papers: Composition operators between Beurling subspaces o…

200 papers

In \cite{CO-Tp-spaces}, the present authors initiated the study of composition operators on discrete analogue of generalized Hardy space $\mathbb{T}_{p}$ defined on a homogeneous rooted tree. In this article, we give equivalent conditions…

Complex Variables · Mathematics 2020-04-08 Perumal Muthukumar , Saminathan Ponnusamy

Let $\zeta$ and $\eta$ be distinct points on the unit circle and suppose that $\phi$ is a linear-fractional self-map of the unit disk D, not an automorphism, with $\phi(\zeta)=\eta$. We describe the C*-algebra generated by the associated…

Operator Algebras · Mathematics 2007-05-23 Thomas L. Kriete , Barbara D. MacCluer , Jennifer L. Moorhouse

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

Let $\varphi$ be a holomorphic map which is a symbol of a bounded composition operator $C_\varphi$ acting on the Hardy-Hilbert space of Dirichlet series. We find a K\"onigs map for $\varphi$. We then deduce several applications on…

Functional Analysis · Mathematics 2024-07-01 Frédéric Bayart , Xingxing Yao

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

We observe that local embedding problems for certain Hardy and Bergman spaces of Dirichlet series are equivalent to boundedness of a class of composition operators. Following this, we perform a careful study of such composition operators…

Complex Variables · Mathematics 2019-11-05 Frédéric Bayart , Ole Fredrik Brevig

We study a semigroup of weighted composition operators on the Hardy space of the disk $H^2(\mathbb{D})$, and more generally on the Hardy space $H^2(U)$ attached to a simply connected domain $U$ with smooth boundary. Motivated by conformal…

Functional Analysis · Mathematics 2018-12-05 Mihai Putinar , James E. Tener

In this paper, we investigate the compactness of the commutator $[C_\psi^{\ast}, C_\varphi]$ on the Hardy space $H^2(B_N)$ or the weighted Bergman space $A^2_s(B_N)$ ($s>-1$), when $\varphi$ and $\psi$ are automorphisms of the unit ball…

Complex Variables · Mathematics 2014-10-07 Liangying Jiang

By classical results of Herglotz and F. Riesz, any bounded analytic function in the complex unit disk has a unique inner-outer factorization. Here, a bounded analytic function is called \emph{inner} or \emph{outer} if multiplication by this…

Functional Analysis · Mathematics 2020-02-05 Michael T. Jury , Robert T. W. Martin , Eli Shamovich

In 1987, Shapiro shew that composition operator induced by symbol $\phi$ is compact on the Lipschltz space if and only if the infinity norm of $\phi$ is less than 1 by a spectral-theoretic argument, where $\phi$ is a holomorphic self-map of…

Functional Analysis · Mathematics 2013-12-30 Zhongshan Fang , Zehua Zhou

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

In this paper we investigate the numerical ranges of composition operators whose symbols are elliptic automorphisms of finite orders, on the Hilbert Hardy space $H^2(D)$.

Functional Analysis · Mathematics 2023-02-22 Yong-Xin Gao , Ze-Hua Zhou

Let $B_d$ denote the unit ball of $\mathbb{C}^d$, $d\ge 1$. Given a holomorphic function $\varphi: B_d \to B_1$, we study the corresponding family $\sigma_\alpha[\varphi]$, $\alpha\in\partial B_1$, of Clark measures on the unit sphere…

Complex Variables · Mathematics 2019-04-10 Aleksei B. Aleksandrov , Evgueni Doubtsov

Let $\phi(z)=(\phi_1(z),...,\phi_n(z))$ be a holomorphic self-map of $B$ and $\psi(z)$ a holomorphic function on $B$, where $B$ is the unit ball of ${\Bbbb C}^n$. Let $0<p,s<+\infty, -n-1<q<+\infty, q+s>-1$ and $\alpha\geq 0,$ this paper…

Complex Variables · Mathematics 2013-12-03 Zehua Zhou , Renyu Chen

We construct an analytic self-map $\Phi$ of the bidisk ${\mathbb D}^2$ whose image touches the distinguished boundary, but whose approximation numbers of the associated composition operator on $H^2 ({\mathbb D}^2)$ are small in the sense…

Functional Analysis · Mathematics 2019-01-23 Daniel Li , Hervé Queffélec , Luis Rodríguez-Piazza

We survey recent results about composition operators induced by analytic self-maps of the unit disk in the complex plane on various Banach spaces of analytic functions taking values in infinite-dimensional Banach spaces. We mostly…

Functional Analysis · Mathematics 2015-05-11 Jussi Laitila , Hans-Olav Tylli

In this note we give a new sufficient condition for the boundedness of the composition operator on the Dirichlet-type space on the disc, via a two dimensional change of variables formula. With the same formula, we characterise the bounded…

Complex Variables · Mathematics 2025-03-18 Athanasios Beslikas

Let $\lambda_i (i=1,...,k)$ be any nonzero complex scalars and $\varphi_i (i=1,..,k)$ be any analytic self-maps of the unit disk $\mathbb{D}$. We show that the operator $\sum_{i=1}^k\lambda_iC_{\varphi_i}$ is compact on the Bloch space…

Complex Variables · Mathematics 2018-02-13 Yecheng Shi , Songxiao Li

Finite-dimensional model spaces are quotient spaces of the Hardy space on the open unit disc, determined by finite Blaschke products. Composition operators, on the other hand, act by composing Hardy space functions with analytic self-maps…

Functional Analysis · Mathematics 2025-09-22 P. Muthukumar , Jaydeb Sarkar , Batzorig Undrakh

We study the hypercyclic, supercyclic and cyclic properties of composition operator $C_{\phi}$ on the Segal-Bargmann space $\mathscr{H}(\mathscr{E})$, where $\phi (z)=Az+b$, $A\in \mathcal{B}(\mathscr{E})$, $b\in \mathscr{E}$ with…

Functional Analysis · Mathematics 2021-03-23 G. Ramesh , B. Sudip ranjan , D. Venku Naidu