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We consider Volterra-type integration operators $T_g$ between Bergman spaces induced by weights $\omega$ satisfying a doubling property. We derive estimates for the operator norms, essential and weak essential norms of $T_g: A_\omega^p \to…

Complex Variables · Mathematics 2015-06-18 Santeri Miihkinen , Pekka Nieminen , Wen Xu

We show that a composition operator induced by an analytic self-map of the unit disc in the complex plane is weakly compact on the space BMOA precisely when the operator is compact on BMOA. As a crucial step we simplify the compactness…

Functional Analysis · Mathematics 2010-01-22 Jussi Laitila , Pekka J. Nieminen , Eero Saksman , Hans-Olav Tylli

We address the problem of studying the boundedness, compactness and weak compactness of the integral operators $T_g(f)(z)=\int_0^z f(\zeta)g'(\zeta)\,d\zeta$ acting from a Banach space $X$ into $H^\infty$. We obtain a collection of general…

Functional Analysis · Mathematics 2016-04-06 Manuel D. Contreras , José A. Peláez , Christian Pommerenke , Jouni Rättyä

We consider operators T : M_0 -> Z and T : M -> Z, where Z is a Banach space and (M_0, M) is a pair of Banach spaces belonging to a general construction in which M is defined by a "big-O" condition and M_0 is given by the corresponding…

Functional Analysis · Mathematics 2016-11-14 Karl-Mikael Perfekt

For analytic functions $g$ on the unit disc with non-negative Maclaurin coefficients, we describe the boundedness and compactness of the integral operator $T_g(f)(z)=\int_0^zf(\zeta)g'(\zeta)\,d\zeta$ from a space $X$ of analytic functions…

Complex Variables · Mathematics 2021-03-17 José Ángel Peláez , Jouni Rättyä , Fanglei Wu

In this paper we characterize the boundedness, compactness, and weak compactness of the integration operators \begin{align*} T_g (f)(z)=\int_{0}^{z} f(w)g'(w)\ dw \end{align*} acting on the average radial integrability spaces $RM(p,q)$. For…

Functional Analysis · Mathematics 2020-05-25 Tanausú Aguilar-Hernández , Manuel D. Contreras , Luis Rodríguez-Piazza

We prove that the notions of compactness and weak compactness for a Hankel operator on BMOA are identical.

Complex Variables · Mathematics 2011-08-16 Michael Papadimitrakis

In the present work, we are interested in compact integration operators $I_g f(z) = \int_0^z f(\zeta)g'(\zeta)d\zeta$ acting on the Hardy space $H^2$ and on the weighted Bergman spaces $\mathcal{A}^2_\alpha$. We give upper and lower…

Complex Variables · Mathematics 2022-06-30 O. El Fallah , F. Mkadmi , Y. Omari

The problem of describing the analytic functions $g$ on the unit disc such that the integral operator $T_g(f)(z)=\int_0^zf(\zeta)g'(\zeta)\,d\zeta$ is bounded (or compact) from a Banach space (or complete metric space) $X$ of analytic…

Complex Variables · Mathematics 2022-11-08 José Ángel Peláez , Jouni Rättyä , Fanglei Wu

We consider weighted composition operators on spaces of analytic functions on the unit disc, which take values in some complex Banach space. We provide necessary and sufficient conditions for the boundedness and (weak) compactness of…

Functional Analysis · Mathematics 2015-02-02 Mostafa Hassanlou , Jussi Laitila , Hamid Vaezi

We obtain exhaustive results and treat in a unified way the question of boundedness, compactness, and weak compactness of composition operators from the Bloch space into any space from a large family of conformally invariant spaces that…

Functional Analysis · Mathematics 2016-11-07 Manuel D. Contreras , Santiago Diaz-Madrigal , Dragan Vukotic

It is shown that a large class of properties coincide for weighted composition operators on a large class of weighted VMOA spaces, including the ones with logarithmic weights and the ones with standard weights $(1-|z|)^{-c}, \ 0\leq c<…

Functional Analysis · Mathematics 2025-04-16 David Norrbo

We prove that a Volterra-type integral operator $T_gf(z) = \int_0^z f(\zeta)g'(\zeta)d\zeta, \, z \in \mathbb D,$ defined on Hardy spaces $H^p, \, 1 \le p < \infty,$ fixes an isomorphic copy of $\ell^p,$ if the operator $T_g$ is not…

Functional Analysis · Mathematics 2015-09-29 Santeri Miihkinen

Let $f$ and $g$ be analytic on the unit disc $\mathbb{D}$. The integral operator $T_g$ is defined by $ T_g f(z) = \int_0^z f(t)g'(t)\,dt$, $z \in \mathbb{D}$. The problem considered is characterizing those symbols $g$ for which $T_g$ acting…

Complex Variables · Mathematics 2024-02-13 Austin Anderson , Mirjana Jovovic , Wayne Smith

In this work, we prove that weak compactness of composition operator on $H^{1}(U^{n})$ coincides with its compactness. We also characterize bounded and compact composition operators on $H^{1}(U^{n}).$\

Complex Variables · Mathematics 2007-05-23 Turgay Bayraktar

We study the properties of the Volterra and Ces\`aro operators viewed on the $L^1$-M\"untz space $M_\Lambda^1$ with range in the space of continuous functions. These operators are neither compact nor weakly compact. We estimate how far from…

Functional Analysis · Mathematics 2016-12-13 Ihab Al Alam , Georges Habib , Pascal Lefèvre , Fares Maalouf

Let $T$ be a $C_0$--contraction on a separable Hilbert space. We assume that $I_H-T^*T$ is compact. For a function $f$ holomorphic in the unit disk $\DD$ and continuous on $\bar\DD$, we show that $f(T)$ is compact if and only if $f$…

Functional Analysis · Mathematics 2008-09-19 Karim Kellay , Mohamed Zarrabi

We study the representation of non-weakly compact operators between $AL$-spaces. In this setting, we show that every operator admits a best approximant in the ideal of weakly compact operators. Using duality arguments, we extend this result…

Functional Analysis · Mathematics 2026-03-30 Antonio Acuaviva , Amir Bahman Nasseri

For $0<p\leq\infty$, let $F^{p}_\varphi$ be the Fock space induced by a weight function $\varphi$ satisfying $ dd^c \varphi \simeq \omega_0$. In this paper, given $p\in (0, 1]$ we introduce the concept of weakly localized operators on $…

Complex Variables · Mathematics 2017-12-21 Zhangjian Hu , Xiaofen Lv , Brett D. Wick

Let $X$ be a pointed compact metric space. Assuming that $\mathrm{lip}_0(X)$ has the uniform separation property, we prove that every weakly compact composition operator on spaces of Lipschitz functions $\mathrm{Lip}_0(X)$ and…

Functional Analysis · Mathematics 2014-05-19 A. Jiménez-Vargas
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