An expansive multiplier property for operator-valued Bergman inner functions

We show that operator-valued Bergman inner functions have the so-called expansive multiplier property generalizing a well-known result of Hedenmalm in the scalar case. This analysis leads to norm bounds for input output maps for a related class of discrete time linear systems. The proof uses properties of the biharmonic Green function (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Construction of Green functions for weighted biharmonic operators

A constructive proof is given of the existence of the weighted biharmonic Green function Γ_α for α?0. The method is used to derive the explicit formula for Γ₁ previously stated by Hedenmalm. In addition, a formula for Γ₂ is found, which is then shown to take both positive and negative values in the bidisk .     

关于小Bloch函数

给出了一个小Bloch函数的几个等价条件。     

解析函数空间上的自伴加权复合算子

通过再生核函数刻画了Hardy空间,Bergman空间上自伴加权复合算子以及自伴等距加权复合算子,最后研究了单位球上的分式线性自同构,得到了一个充分条件。     

加权调和Bergman核及其诱导的度量矩阵

在Rn中的有界域上建立加权调和Bergman核,并得出单位球的加权调和Bergman核的表达式;利用加权调和Bergman核在Rn的有界域上构造度量矩阵;得到关于调和映射的Jacobi矩阵与度量矩阵之间的一个不等式.     

The behaviour on the rays of functions from the Bergman and Fock spaces

In this note we study the behaviour of holomorphic functions from the Bergman and Fock spaces on the rays of the unit disc U and the complex plane ℂ. We obtain conditions on the finiteness of weighted L ²-integrals of those functions along rays.      

A~2(Ф)上多重换位子的有界性(英文)

本文研究了加权Ｂｅｒｇｍａｎ空间Ａ２（）上的多重换位子．利用Ｂｅｒｇｍａｎ几何，解析函数的性质及有关分析，刻划了具有共轭解析符号的多重换位子有界的特征．     

A note on polyharmonic functions

In this note we prove the following theorem:Suppose 0<p<∞ and α>−1. Then there is a constant C=C(p,m,n,α) such that

     

On integral means of star-like functions

We study univalent holomorphic functions in the unit diskU = {z: |z| < 1} of the formf(z)=z+∑ _n=2 ^∞ a _n z ⁿ that satisfy the condition Re zf’(z)/f(z) > α with α∈ [0, 1) inU. Some integral means of such funcions are estimated.     

On the existence of polyanalytic functions

We give a sharp estimate for the codimension of the poly‐Bergman space in the poly‐Bergman space over the punctured domain. It is established the behaviour at the infinity point of polyanalytic Bergman functions on the complement of closed disks. In the main result of the paper, we prove that for and the j‐polyanalytic Bergman space over the domain U is trivial precisely when the complement of U has at most one point and at most two points or three points lying in a circle, respectively. We point out the differences between the domains over which the Bergman space and the non‐analytic poly‐Bergman space are trivial.     

An integral representation of functions

We obtain an integral representation of functions of real variables which can be considered (at least formally) as some analog of the Fourier formula.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 47, pp. 67–72, 1974.     

Ap(ψ)上Toeplitz算子的半换位子

本文给出加权Bergman空间Ap(ψ)上具有界调和符号的Toeplitz算子的半换位子为零或为紧算子的一些充要条件.     

Ap(ψ)上Toeplitz算子的换位子

本文使用不变加权面积平均值性质刻画了单位圆盘内的调和函数.由此我们探讨了加权Bergman空间Ap(ψ)上的Toeplitz算子,给出了两个具有界调和符号的Toeplitz算子交换或本质交换的一些充要条件.     

On the functions of one selfadjoint integral operator

We construct a selfadjoint Akhiezer integral operator S on L ₂(?1, 1) with the spectrum {?1; 0; 1} and the property that every function φ(S) that is not a multiple of S fails to be an Akhiezer integral operator.     

加权Begman空间的加权复合算子的本性模

利用上极限,给出了单位球上加权Bergman空间的加权复合算子的本性模的表示．     

On one representation of analytic functions by harmonic functions

Let u(x) be a function analytic in some neighborhood D about the origin, $ \mathcal{D} Let u(x) be a function analytic in some neighborhood D about the origin, ⊂ ℝ ⁿ . We study the representation of this function in the form of a series u(x) = u ₀(x) + |x|² u ₁(x) + |x|⁴ u ₂(x) + …, where u _k (x) are functions harmonic in . This representation is a generalization of the well-known Almansi formula. Original Russian Text ? V. V. Karachik, 2007, published in Matematicheskie Trudy, 2007, Vol. 10, No. 2, pp. 142–162.