广义弱亚正规算子的正规性

主要研究了T是广义弱亚正规算子时,T~t是拟正规算子的充要条件是T是拟正规算子.并且举例说明了存在非次正规的广义弱亚正规算子T使得T~t是次正规的.     

Dirichlet空间上Toeplitz算子的亚正规性

讨论单位圆盘中Dirichlet空间上Toeplitz算子的性质,给出了Dirichiet空间上以一类连续函数为符号的Toeplitz算子满足亚正规性的充分必要条件．     

有关p-亚正规算子和对数亚正规算子广义Aluthge变换的一个注解

We shall give some results on generalized aluthge transformation for p-hyponormal and log-hyponormal operators.We shall also discuss the best possibility of these results.     

关于加权移位算子的n-亚正规性

对于较Bergman加权移位序列更一般的序列,利用无穷维矩阵的正定性得到了其n-亚正规性,推广了已有的一些结论.     

C_2(H)上初等算子的拟正常性

本文主要给出了 C_2(H)上初等算子 X(?)AXB+MXN 为拟正常的充要条件,其中{A,M}、{B,N}分别为双交换有界线性算子.作为推论,给出了[1]中相应的结果.     

p-亚正常算子的本质谱与拟相似

本文证明了每一个ｐ－亚正常算子Ａ,都相应存在一个亚正常算子 ,使得Ａ与 有相同的闭值域点、相同的本质谱和谱．由此推出如果Ａ是ｐ－亚正常算子,Ｂ是任一有界线性算子,若存在有界线性算子Ｘ有稠值域,使得ＸＢ＝ＡＸ,则σ（Ａ）（Ｂ）此外还证明了,如果Ａ是ｐ－亚正常算子且 Ｒ（Ａ）闭或ＫｅｒＡ＝ＫｅｒＡ*, Ｂ是任一有界线性算子,Ａ与Ｂ拟相似,则ｅ（Ａ）（Ｂ）．     

关于某些次正规算子的表示

设T是完全非正规的次正规算子。给出了T＝N＋K的充要条件，其中N是正规算子，K是拟正规算子，且NK＝KN。     

关于p-弱亚正规算子的一个注记

对0相似文献   

多元拟亚纯映射的正规族

文章应用覆盖曲面的几何方法讨论了多元拟亚纯映射的正规定理。     

拟-k-仿正规算子的一个注解

设T是复希尔伯特空间H上的有界线性算子,若对任意的x∈H,T满足||T~(k+2)x||||Tx||~k≥||T~2x||~(k+1),则称T为拟-k-仿正规算子,其中k为正整数.该文给出了拟-k-仿正规算子的一些性质,如拟-k-仿正规算子是极,作为此性质的应用,证明了拟-k-仿正规算子满足Weyl定理.     

Analytic Characterization for Hilbert-Schmidt Operators on Fock Space

In this paper we first introduce and investigate some special classes of nonlinear maps and get several useful results. Then, by using these results, we obtain analytic criteria for checking whether or not an operator defined only on the exponential vectors of a symmetric Fock space becomes a Hilbert-Schmidt operator on the whole space. Additionally, as an application, we also get an analytic criterion for Hilbert-Schmidt operators on a Gaussian probability space through the Wiener-Ito-Segal isomorphism.     

圆环上的一类Toeplitz算子

本文描述了圆环的Ｂｅｒｇｍａｎ空间上以径向函数为符号的Ｔｏｅｐｌｉｔｚ算子的谱,有界性以及紧性。     

A Class of Operators on Lh 2

Let D be the open unit disc in ? and let L_h ² be the space of quadratic integrable harmonic functions defined on D. Let \(\varphi: {\bar D}\rightarrow {\rm C}\) be a function in L^∞(D) with the property that φ(b) = lim_x→b,x?Dφ(x) for all b ? ?D. Define the operator C_φ in L_h ² as follows: C_φf = Q(φ·f),f ? L_h ², where Q is the orthogonal projection from L² (D) on L_h ². The following results are proved. If φ¦_?D ≡ 0, then C_φ is a compact linear operator and if φ¦_?D vanishes nowhere, then C_φ is a Fredholm operator.     

A Note on a Class of Operators

The aim of this note is to study the spectral properties of the LUECKE's class R of operators T such that ‖(T – zI)^?1‖=1/d(z, W(T)) for all z?CLW(T), where CLW(T) is the closure of the numerical range W(T) of T and d(z, W(T)) is the distance from z to W(T). The main emphasis is on the investigation of those properties of operators of class R which are either similar to or distinct from those of operators satisfying the growth condition (G₁).     

A Class of Operators on Weighted Bergman Spaces

This paper studies the connection between an analytic function φ on the unit disk and a certain type of operators induced by φ on weighted Bergman spaces A ^α of analytic functions on . The general theme is the interplay between smoothness conditions on φ and the S _p -norms of the operators induced by φ.      

Fock空间上的一类加权复合算子

This paper studies a class of weighted composition operators and their spectrum on the Fock space.As an application,bounded self-adjoint,a class of complex symmetric weighted composition operators on the Fock space are characterized.     

On the Cowen-Douglas Class for Banach Space Operators

In [3], M. J. Cowen and R. G. Douglas prove that the adjoint of a Hilbert space operator T is in the class if and only if T is unitarily equivalent with the operator M _z on a Hilbert space -valued analytic functions, where M _z denotes the operator of multiplication by the independent variable. The proof involves holomorphic vector bundles and Grauert’s theorem. In this paper we use a theorem by I. Gohberg and L. Rodman [4] to give a more elementary proof of this fact, which also works for Banach space operators.      

The Saturation Class of Shepard Operators

The saturation problem of the Shepard operators for 1 2 is completely settled.     

On a Class of Covariance Operators

This paper is the continuation of [1] in which complex symmetries of distributions and their covariance operators are investigated. Here we also study the most general quaternion symmetries of random vectors. Complete classification theorems on these symmetries are proved in terms of covariance operator spectra.     

On a Class of Integral Operators

In this paper we consider the space where dv _s is the Gaussian probability measure. We give necessary and sufficient conditions for the boundedness of some classes of integral operators on these spaces. These operators are generalizations of the classical Bergman projection operator induced by kernel function of Fock spaces over .