On The Exact Norm Value Op Some Bmoa Functions

In this paper we construct two large classes of BMOA functions with BMOA norm equal to the H² norm, respecting equal to the H^∞ norm. We also determine all functions in the disc algebra with BMOA norm equal to the Bloch norm.     

多复变量的Bα到BMOA的复合算子

本文研究了Bα(Bm)到BMOA(Bn)上的复合算子.利用Caxleson测度的等价条件,得到了Bα(Bm)到BMOA(Bn)上复合算子的有界和紧性的特征,推广了Bloch空间上复合算子的相应结果.     

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.     

各向异性函数空间上的多线性算子的估计及其应用

设A是Rn上的各向异性伸缩,L是由各向异性Calderón-Zygmund算子生成的一般的多线性算子.本文得到L从加权Lebesgue空间Lp(Rn)到无权的各向异性Hardy空间HpA(Rn)的有界性.另外,对各向异性Hardy空间H1(Rn)和加权各向异性BMO空间BMOwA(Rn)得到包含关系:BMOX(Rn)(...     

BMOA空间与Bloch型空间之间的加权Cesáro算子

本文研究单位圆盘上的BMOA空间和α-Bloch型空间之间的加权Cesáro算子,给出了T_g是BMOA空间到B_α空间的有界算子或紧算子的充分必要条件。     

Compactness of composition operators on BMOA and VMOA

We give a new and simple compactness condition for composition operators on BMOA,the space of all analytic functions of the bounded mean oscillation on the unit disk.Using our results one may immediately obtain that compactness of a composition operator on BMOA implies its compactness on the Bloch space as well as on the Hardy space.Similar results on VMOA are also given.     

BMOA空间与Bloch型空间之间的加权Ces\''{a}ro算子

本文研究单位圆盘上的BMOA空间和$\a$-Bloch型空间之间的加权 Ces\'{a}ro 算子,给出了$\tg$是BMOA空间到$\ba$空间的有界算子或紧算子的充分必要条件.     

Action of Convolution and Toeplitz Operators in Spaces of BMOA type

In this paper, we describe coefficient multipliers, study the action of fractional derivatives of spaces of BMOA type and the action of Toeplitz operators in these classes.     

Compact Composition Operators on BMOA

We characterize the compact composition operators on BMOA, the space consisting of those holomorphic functions on the open unit disk that are Poisson integrals of functions on , that have bounded mean oscillation. We then use our characterization to show that compactness of a composition operator on BMOA implies its compactness on the Hardy spaces (a simple example shows the converse does not hold). We also explore how compactness of the composition operator relates to the shape of near , introducing the notion of mean order of contact. Finally, we discuss the relationships among compactness conditions for composition operators on BMOA, VMOA, and the big and little Bloch spaces.

     

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.

     

On a class of lacunary series in BMOA

In this paper we consider a special class of lacunary series and we characterize their membership in the BMOA of the unit ball of Cn in terms of their Taylor coefficients. In addition, we show that a similar result holds for the class VMOA.     

On the BMO boundedness of the Cauchy integral on a chord-arc curve

Archiv der Mathematik - A detailed proof is given for the boundedness of the Cauchy integral acting on BMO on a chord-arc curve. Some applications are given to the Faber operator on BMOA and to the...     

Superposition operators between the Bloch space and Bergman spaces

Using a geometric method, we characterize all entire functions that transform the Bloch space into a Bergman space by superposition in terms of their order and type. We also prove that all superposition operators induced by such entire functions act boundedly. Similar results hold for superpositions from BMOA into Bergman spaces and from the Bloch space into certain weighted Hardy spaces.     

On Subspaces of Bloch Space and Series with Hadamard Gaps

本文研究了由修改的Ｂｅｓｏｖ模和Ｃａｒｌｅｓｏｎ测度所定义的Ｂｌｏｃｈ空间的一类子空间．利用这类子空间与Ｈａｄａｍａｒｄ缺项级数之间的关系，证明了他们之间的包含关系．作为所得结果的一个简单推论，本文对Ｋ．Ｓｔｒｏｅｔｈｏｆ关于ＢＭＯＡ和ＶＭＯＡ的一个未解决的问题作出了否定的回答．     

BMOA空间的循环元

在文中，刻划了BMOA空间的循环元，得到了f是BMOA空间循环元的充分必要条件是f为外函数．     

Composition Operators and Vector-valued BMOA

Analytic composition operators are studied on X-valued versions of BMOA, the space of analytic functions on the unit disk that have bounded mean oscillation on the unit circle, where X is a complex Banach space. It is shown that if X is reflexive and C _φ is compact on BMOA, then C _φ is weakly compact on the X-valued space BMOA _C (X) defined in terms of Carleson measures. A related function-theoretic characterization is given of the compact composition operators on BMOA.     

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).     

Generalized Hardy Transformation and Toeplitz Operators in BMOA-Type Spaces

We study the action of the generalized Hardy transformation in the BMOA classes in a half-disk and present a criterion for the boundedness of the Toeplitz operators acting in a BMOA-type space in the unit disk.     

Hyperbolic BMOA classes

Let φ be a holomorphic mapping between complex unit balls. We obtain several characterizations of those φ for which the Möbius-invariant BMOA condition holds with respect to the Bergman metric.