解析函数空间中复合算子的平均遍历性（英文）

本文研究了复合算子的遍历性问题.利用经典算子理论的方法,获得了单位圆上加权Banach空间中复合算子遍历性的结果,我们还得到单位圆上Hardy空间中类似的结果,我们的结论是对乘子算子相关结果的推广.     

关于复平面上H~∞空间,β~p空间以及β_0~p空间的几个问题

本文讨论了单位圆中Hardy空间H∞到p-Bloch空间βP的复合算子T1.φ加权复合算子Tψ,(?)的有界性,也讨论了H∞到小p-Bloch空间β6的复合算子T1,(?)的有界性问题;另外还讨论了小p-Bloch空间到H∞空间的点乘子及小p-Bloch空间上复合算子的紧性等.     

关于复平面上H∞空间,βp空间以及βp0空间的几个问题

本文讨论了单位圆中Hardy空间H∞到p-Bloch空间βp的复合算子T1,φ和加权复合算子Tψ,ψ的有界性,也讨论了H∞到小p-Bloch空间ββ的复合算子T1,ψ的有界性问题;另外还讨论了小p-Bloch空间到H∞空间的点乘子及小p-Bloch空间上复合算子的紧性等.     

Bloch 空间上的复合算子的下有界性

证明Ghatage, Yan和Zheng所给的单位圆的Bloch空间上的复合算子的下有界性的必要条件也是充分的. 进而得到高维单位球的Bloch空间上的复合算子的下有界性的一个充分条件和一个必要条件.     

p-Bloch空间上的复合算子和加权复合算子

本文系统地讨论了单位圆中p-Bloch空间上复合算子T1,ψ的有界性和紧性以及加权复合算子Tψ,ψ的有界性,同时也在小p-Bloch空间上讨论了复合算子T1,ψ的有界性问题.主要得到以下结论(i)Tψ,ψ是空间βp到βq的有界算子之充要条件;(ii)T1,ψ是空间βp到βq的紧算子之充要条件;(iii)T1,ψ是空间βp0到βq0的有界算子之充要条件等.从空间或算子上扩展了文[1,4]的相应结论.     

p-Bloch空间上的复合算子和加权复合算子

本文系统地讨论了单位圆中p-Bloch空间上复合算子T1,δ的有界性和紧性以及加权复合算子Tφ,δ的有界性,同时也在小p-Bloch空间上讨论了复合算子T1,φ的有界性问题.主要得到以下结论: (i)Tφ,δ是空间βp到βq的有界算子之充要条件; (ii)T1,φ是空间βp到βq的紧算子之充要条件; (iii)T1,φ是空间βp0到βq0的有界算子之充要条件等.从空间或算子上扩展了文[1,4]的相应结论.     

不同权的Bloch型空间之间的加权复合算子再刻画

本文研究了单位圆中从空间β_L到β_α的加权复合算子uC_φ为有界算子和紧算子的条件.利用阶估计等方法,获得了有界性和紧性的简捷充要条件,推广了叶善力的相应结果.     

从α-Zygmund空间到β-Bloch空间的加权复合算子

该文得到了从单位圆上α-Zygmund空间到β-Bloch空间的加权复合算子的有界性和紧性的充分且必要的条件.     

从Hardy空间到加权Bloch型空间的加权复合算子

研究了单位圆上从Hardy空间到α-Bloch空间的加权复合算子uC_φ的有界性和紧性.分别给出从H~p空间到β~α空间和β_0~α空间的算子uC_φ的有界性和紧性的充分和必要条件.     

单位球上加权Begrman空间和Hardy空间上的保范复合算子

作者证明了复合算子C_φ是单位球上加权Begrman空间上的保范算子当且仅当φ是旋转变换.对单位球上的Hardy空间上的保范复合算子仅得到部分结果.     

Mean ergodicity of multiplication operators in weighted spaces of holomorphic functions

Multiplication operators in weighted Banach (and locally convex) spaces of functions holomorphic in the unit disc are well known. In this note we investigate the connection between power boundedness, mean ergodicity and uniform mean ergodicity of such operators. Received: 13 October 2008, Revised: 18 November 2008     

Isolated points and essential components of composition operators on

We consider the topological space of all composition operators on the Banach algebra of bounded analytic functions on the unit disk. We obtain a function theoretic characterization of isolated points and show that each isolated composition operator is essentially isolated.

     

A characterization for a complete random normed module to be mean ergodic

In this paper, we first study the mean ergodicity of random linear operators using some techniques of measure theory and L ⁰-convex analysis. Then, based on this, we give a characterization for a complete random normed module to be mean ergodic.     

Algebraic Properties of Toeplitz Operators on the Harmonic Dirichlet Space

We study some algebraic properties of Toeplitz operators on the harmonic Dirichlet space of the unit disk. We first give a characterization for boundedness of Toeplitz operators. Next we characterize commuting Toeplitz operators. Also, we study the product problem of when product of two Toeplitz operators is another Toeplitz operator. The corresponding problems for compactness are also studied.     

Topological Structure of the Space of Weighted Composition Operators on H ∞

We study properties of the topological space of weighted composition operators on the space of bounded analytic functions on the open unit disk in the uniform operator topology. Moreover, we characterize the compactness of differences of two weighted composition operators.     

Compactness of composition operators on BMOA

A function theoretic characterization is given of when a composition operator is compact on BMOA, the space of analytic functions on the unit disk having radial limits that are of bounded mean oscillation on the unit circle. When the symbol of the composition operator is univalent, compactness on BMOA is shown to be equivalent to compactness on the Bloch space, and a characterization in terms of the geometry of the image of the disk under the symbol of the operator results.

     

Compact Differences of Composition Operators over Polydisks

Moorhouse characterized compact differences of composition operators acting on a weighted Bergman space over the unit disk of the complex plane. She also found a sufficient condition for a single composition operator to be a compact perturbation of the sum of given finitely many composition operators and studied the role of second order data in determining compact differences. In this paper, based on the characterizations due to Stessin and Zhu, of boundedness and compactness of composition operators acting from a weighted Bergman space into another, we obtain the polydisk analogues of Moorhouse’s results through a different approach in main steps. In addition we find a necessary coefficient relation for compact combinations which was first noticed on the disk by Kriete and Moorhouse.     

Reverse estimates in logarithmic Bloch spaces

We obtain sharp reverse estimates for the logarithmic Bloch spaces on the unit disk. As an application, we study composition operators with values in the space BMOA.     

Complete continuity of linear combinations of composition operators

In this note, we characterize complete continuity of linear combinations of composition operators on Hardy and Bergman spaces of the unit disk.     

Compact Toeplitz operators on the Segal-Bargmann space

In this note, we show that Miao and Zheng's characterization of compact operators on the Bergman space of the unit disk that are finite sums of finite products of Toeplitz operators (with each one of the symbols belonging to BT) also holds for the Segal-Bargmann space of Cn.