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Related papers: Compact composition operators on model spaces

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Let $\phi(z)=(\phi_1(z),...,\phi_n(z))$ be a holomorphic self-map of $B_n$ and $\psi(z)$ a holomorphic function on $B_n$, and $H(B_n)$ the class of all holomorphic functions on $B_n$, where $B_n$ is the unit ball of $C^n$, the weight…

Functional Analysis · Mathematics 2013-12-30 Zhong-Shan Fang , Ze-Hua Zhou

Let $\varphi$ be a holomorphic self map of the bidisc that is Lipschitz on the closure. We show that the composition operator $C_{\varphi}$ is compact on the Bergman space if and only if $\varphi(\overline{\mathbb{D}^2})\cap…

Complex Variables · Mathematics 2025-07-22 Timothy G. Clos , Zeljko Cuckovic , Sonmez Sahutoglu

Let $\phi$ be a linear-fractional self map of the open unit disk, not an automorphism, such that $\phi(\zeta)=\eta$ for distinct points $\zeta,\eta$ in the unit circle. We consider the question of which composition operators lie in the…

Functional Analysis · Mathematics 2008-10-31 Thomas Kriete , Barbara MacCluer , Jennifer Moorhouse

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

In this paper we initiate the study of composition operators on the noncommutative Hardy space $H^2_{\bf ball}$. Several classical results about composition operators (boundedness, norm estimates, spectral properties, compactness,…

Functional Analysis · Mathematics 2011-11-15 Gelu Popescu

The aim of this paper is to study when two composition operators on the Hilbert space of Dirichlet series with square summable coefficients belong to the same component or when their difference is compact. As a corollary we show that if a…

Functional Analysis · Mathematics 2021-09-21 Frédéric Bayart , Maofa Wang , Xingxing Yao

We give a necessary and sufficient condition for a holomorphic self-map $\phi$ of the tridisc to induce a bounded composition operator on the associated Hardy space. This condition depends on the behaviour of the first and the second…

Functional Analysis · Mathematics 2023-12-06 Frédéric Bayart

We consider the products of composition and differentiation operators on the Hardy space. We provide a complete characterization of the boundedness and compactness of these operators. Furthermore, we obtain the explicit condition for these…

Functional Analysis · Mathematics 2021-08-17 Mahbube Moradi , Mahsa Fatehi

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

The boundedness and compactness of weighted composition operators on the Hardy space ${\mathcal H}^2$ of the unit disc is analysed. Particular reference is made to the case when the self-map of the disc is an inner function. Schatten-class…

Functional Analysis · Mathematics 2009-07-15 Eva A. Gallardo-Gutiérrez , Romesh Kumar , Jonathan R. Partington

When G is a region in the complex plane, compact composition operators on the uniform algebra of bounded analytic functions on G and the spectra of these operators were described by D. Swanton, Compact composition operators on B(D), Proc.…

Functional Analysis · Mathematics 2007-05-23 J. F. Feinstein , Herbert Kamowitz

In this paper, we characterize the boundedness and the compactness of weighted composition operators acting on a de Branges-Rovnyak space $\mathcal H(b)$, where the symbol $b$ is a rational function in the unit ball of $H^\infty$ that is…

Complex Variables · Mathematics 2025-12-18 Emmanuel Fricain , Muath Karaki , Javad Mashreghi , Maëva Ostermann

We first obtain a simpler proof of the main results in [IEOT, {\bf 93}(2021), 17], which characterized the bounded and compact differences $C_{u,\varphi}-C_{v,\psi}$ of two weighted composition operators acting from…

Functional Analysis · Mathematics 2025-07-29 Jiaoye Du , Cezhong Tong , Zicong Yang

For approximation numbers $a_n (C_\phi)$ of composition operators $C_\phi$ on weighted analytic Hilbert spaces, including the Hardy, Bergman and Dirichlet cases, with symbol $\phi$ of uniform norm $< 1$, we prove that $\lim_{n \to \infty}…

Functional Analysis · Mathematics 2014-07-09 Daniel Li , Hervé Queffélec , Luis Rodriguez-Piazza

We construct an analytic self-map $\phi$ of the unit disk and an Orlicz function $\Psi$ for which the composition operator of symbol $\phi$ is compact on the Hardy-Orlicz space $H^\Psi$, but not compact on the Bergman-Orlicz space…

Functional Analysis · Mathematics 2010-06-01 Pascal Lefèvre , Daniel Li , Hervé Queffélec , Luis Rodriguez-Piazza

Suppose $\mathcal{H}$ is a weighted Hardy space of analytic functions on the unit ball $\mathbb{B}_n\subset\mathbb{C}^n$ such that the composition operator $C_\psi$ defined by $C_{\psi}f=f\circ\psi$ is bounded on $\mathcal{H}$ whenever…

Functional Analysis · Mathematics 2012-09-04 S. Waleed Noor

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

We study embeddings of model (star-invariant) subspaces $K^p_{\Theta}$ of the Hardy space $H^p$, associated with an inner function $\Theta$. We obtain a criterion for the compactness of the embedding of $K^p_{\Theta}$ into $L^p(\mu)$…

Complex Variables · Mathematics 2015-05-13 Anton D. Baranov

The main purpose of this paper is to investigate characterizations of composition operators on Bloch and Hardy type spaces. Initially, we use general doubling weights to study the composition operators from harmonic Bloch type spaces on the…

Complex Variables · Mathematics 2023-12-11 Shaolin Chen , Hidetaka Hamada

We show that there exist non-compact composition operators in the connected component of the compact ones on the classical Hardy space $H^2$ on the unit disc. This answers a question posed by Shapiro and Sundberg in 1990. We also establish…

Functional Analysis · Mathematics 2007-06-20 Eva A. Gallardo-Gutiérrez , Maria J. González , Pekka Nieminen , Eero Saksman