Weighted Composition Operators from the Bloch Space to Weighted Banach Spaces on Bounded Homogeneous Domains

We study the bounded and the compact weighted composition operators from the Bloch space into the weighted Banach spaces of holomorphic functions on bounded homogeneous domains, with particular attention to the unit polydisk. For bounded homogeneous domains, we characterize the bounded weighted composition operators and determine the operator norm. In addition, we provide sufficient conditions for compactness. For the unit polydisk, we completely characterize the compact weighted composition operators, as well as provide ＂computable＂ estimates on the operator norm.     

A Note on Weighted Comp osition Op erators on the Fo ck Space

Based on a new characterization of bounded and compact weighted composition operators on the Fock space obtained by Le T(Le T. Normal and isometric weighted composition operators on the Fock space. Bull. London. Math. Soc., 2014,46: 847–856), this paper shows that a bounded weighted composition operator on the Fock space is a Fredholm operator if and only if it is an invertible operator, and if and only if it is a nonzero constant multiple of a unitary operator. The result is very different from the corresponding results on the Hardy space and the Bergman space.     

Frame multiresolution analysis and infinite trees in Banach spaces on locally compact abelian groups

We extend the concept of frame multiresolution analysis to a locally compact abelian group and use it to define certain weighted Banach spaces and the spaces of their antifunctionals. We define analysis and synthesis operators on these spaces and establish the continuity of their composition. Also, we prove a general result to characterize infinite trees in the above Banach spaces of antifunctionals. This paper paves the way for the study of corresponding problems associated with some other types of Banach spaceson locally compact abelian groups including modulation spaces.     

Composition operators on Dirichlet spaces and Bloch space

In this paper we give a Carleson measure characterization for the compact composition operators between Dirichlet type spaces. We use this characterization to show that every compact composition operator on Dirichlet type spaces is compact on the Bloch space.     

The role of BMOA in the boundedness of weighted composition operators on the unit ball

We study the weighted composition operators Wh,on Hardy space H2(B) whenever h ∈ BMOA(resp.h ∈ VMOA).Analogous results are given for Hp(B) spaces and the scale of weighted Bergman spaces.In the latter case,BMOA is replaced by the Bloch space(resp.VMOA by the little Bloch space).     

COMPACT COMPOSITION OPERATORS ON WEIGHTED BERGMAN SPACES ON BOUNDED SYMMETRIC DOMAINS

In this article, we borrow the idea of using Schur’s test to characterize the compactness of composition operators on the weighted Bergman spaces in a bounded symmetric domain Ω, and verify that Cφ is compact on L q a (Ω, dv β ) if and only if K ( φ ( z ) ,φ ( z )) K ( z,z ) → 0 as z →φΩ under a mild condition, where K(z, w) is the Bergman kernel.     

WEIGHTED COMPOSITION OPERATORS ON WEIGHTED DIRICHLET SPACES

We characterize the boundedness and compactness of weighted composition operators on weighted Dirichlet spaces in terms of Nevanlinna counting functions and Caxleson measure.     

AN UPPER BOUND OF THE ESSENTIAL NORM OF COMPOSITION OPERATORS BETWEEN WEIGHTED BERGMAN SPACES

In this paper, we define the generalized counting functions in the higher dimensional case and give an upper bound of the essential norms of composition operators between the weighted Bergman spaces on the unit ball in terms of these counting functions. The sufficient condition for such operators to be bounded or compact is also given.     

Weighted composition operators on the Fock space

In this paper,we study weighted composition operators on theFock space F².We prove that each bounded composition operator on F² is complex symmetric.This is in sharp contrast with the phenomenon on the Hardy space H²(D).We characterize Hermitian weighted composition operators and algebraic weighted composition operators with degree less than or equal to two on F².In addition,we investigate cyclicity and hypercyclicity of complex symmetric weighted composition operators.We also characterize those weighted compositionoperators that preserveframes,tight frames or normalized tight frames on F².Finally,we study mean ergodicity and uniformly mean ergodicity of weighted composition operators.     

TOEPLITZ OPERATORS FROM HARDY SPACES TO WEIGHTED BERGMAN SPACES IN THE UNIT BALL OF Cn

We study Toeplitz operators from Hardy spaces to weighted Bergman spaces in the unit ball of Cⁿ.Toeplitz operators are closely related to many classical mappings,such as composition operators,the Volterra type integration operators and Carleson embeddings.We characterize the boundedness and compactness of Toeplitz operators from Hardy spaces H^p to weighted Bergman spaces A_α^q for the different values of p and q in the unit ball.     

Compact differences of composition operators

A characterization of compact difference is given for composition operators acting on the standard weighted Bergman spaces and necessary conditions are given on a larger scale of weighted Dirichlet spaces. Conditions are given under which a composition operator can be written as a finite sum of composition operators modulo the compacts. The additive structure of the space of composition operators modulo the compact operators is investigated further and a sufficient condition is given to insure that two composition operators lie in the same component.     

HardyOrlicz空间之间的加权复合算

该文研究了复平面中单位圆盘上不同Hardy-Orlicz空间之间的加权复合算子,利用Carleson测度不等式给出了有界或紧的加权复合算子ωC_φ:N_p→N_q的特征. 作为推论得到了加权复合算子ωC_φ:N_p→N_q有界(或紧)的充分必要条件是ωC_φ:H_p→H_q是有界(或紧)的. 此外,还给出了Hardy-Orlicz空间上可逆及Fredholm复合算子的特征.     

Composition operators acting on holomorphic Sobolev spaces

We study the action of composition operators on Sobolev spaces of analytic functions having fractional derivatives in some weighted Bergman space or Hardy space on the unit disk. Criteria for when such operators are bounded or compact are given. In particular, we find the precise range of orders of fractional derivatives for which all composition operators are bounded on such spaces. Sharp results about boundedness and compactness of a composition operator are also given when the inducing map is polygonal.

     

不同Bers型空间之间的加权复合算子

该文讨论了单位圆盘上不同Bers型空间之间的加权复合算子的有界性、紧性和弱紧性, 给出了一些充分必要的判别条件, 特别地得到不同Bers型空间上加权复合算子的紧性与弱紧性的等价性. 这些推广了经典的复合算子与乘法算子的相关结论. 该文同时也给出了Bers型空间上复合算子的Fredholm性和闭值域问题的刻画, 完善了文献[6]中结论.     

Isometric weighted composition operators on weighted Banach spaces of type

We characterize those weighted composition operators on weighted Banach spaces of holomorphic functions of type which are an isometry.

     

Quasinormal and Hyponormal Weighted Composition Operators on $$H^2$$ and $$A^2_{\alpha }$$Aα2 with Linear Fractional Compositional Symbol

In this paper, we study quasinormal and hyponormal composition operators \(W_{\psi ,\varphi }\)  with linear fractional compositional symbol \(\varphi \) on the Hardy and weighted Bergman spaces. We characterize the quasinormal composition operators induced on \(H^{2}\) and \(A_{\alpha }^{2}\) by these maps and many such weighted composition operators, showing that they are necessarily normal in all known cases. We eliminate several possibilities for hyponormal weighted composition operators but also give new examples of hyponormal weighted composition operators on \(H^2\) which are not quasinormal.     

Hardy空间之间的加权复合算子

本文研究了复平面中单位圆盘D上不同Hardy空间之间的加权复合算子，利用Carleson测度的概念分别给出了有界或紧的加权复合算子的充分必要条件。本文也用角数的概念给出了紧加权复合算子的一个必要条件。     

加权Bergman空间上的Carleson测度与复合算子

本文研究了复平面上单位圆盘D上具有指数型权的加权Bergman空间上的Carleson测度和复合算子。利用Carleson测度的概念分别给出了有界或紧的复合算子的充分必要条件。     

Linear relations in the Calkin algebra for composition operators

We consider this and related questions: When is a finite linear combination of composition operators, acting on the Hardy space or the standard weighted Bergman spaces on the unit disk, a compact operator?