Toeplitz算子空间的W—闭包

本文讨论了Ｔｏｅｐｌｉｔｚ算子空间的Ｗ－闭包，我们证明了Ｂｅｒｇｍａｎ空间Ｌ＾２ａ（Ｄ）上全体Ｔｏｅｐｌｉｔｚ算子的Ｗ闭包等于Ｂ（Ｌ＾２ａ（Ｄ）（定理１），另外，我们给出Ｃ＾ｍ（ｎ＞１）中单位球面Ｓ上的Ｈａｒｄｙ空间Ｈ＾２（Ｓ）上的Ｔｏｅｐｌｉｔｚ算子的一个有趣刻划（命题２）。     

算子方程AX-XA=C的可解性

本文在一般Ｂａｎａｃｈ空间研究带无界算子Ａ的算子方程ＡＸ－ＸＡ＝Ｃ的可解性,利用单参数积分双半群方法,通过在算子代数Ｌ（Ｅ）上考虑间断问题弱解,证明了当算子Ａ在Ｌ（Ｅ）上诱导的算子Ａ是弱积分双半群的母元时,只要Ｃ满足一定条件,上述算子方程可解．     

解析函数的Banach空间上之复合算子

本文研究了一类解析函数的Ｂａｎａｃｈ空间Ｘ上之复合算子，这类空间包含了Ｂｌｏｃｈ空间，并且可看作Ｂｅｒｇｍａｎ空间Ｌ１ａ（Ｄ）中具有原子分解的解析函数的对偶空间．我们刻划了这类空间上紧复合算子及Ｆｒｅｄｈｏｌｍ复合算子的特征，此外，还研究了具有闭值域的复合算子．     

关于算子─（△—ia）~2＋Ⅴ的性质（Ⅰ）

关于算子─（△—ia）￣２＋Ⅴ的性质（Ⅰ）余开奇，马吉薄（南京航空航天大学数理力学系，２１００１６）（南京大学数学系，２１０００８）关键词自伴算子，本质自扩张，Ｓｃｈｒｏｄｉｕｇｅｒ算子．分类号ＡＭｓ（１９９１）４７Ｆ０５，４７Ｂ８０／ＣＣＬＯ１７７．...     

线性正算子序列在空间C_m(D)的收敛性问题

本文将Коровкин关于线性正算子序列和线性连续多项式算子序列逼近一元连续函数的主要结果推广到ｍ维连续函数空间Ｃｍ（Ｄ）．     

A~2(Ω,dV_α)空间上Schatten类复合算子

让Ａ２（Ω,ｄＶα）表示Ｌ２（Ω,ｄＶα）中的解析函数的全体,它是Ｌ２（Ω,ｄＶα）的闭子空间．本文研究了Ａ２（Ω,ｄＶα）上的具有符号ｂ的复合算子Ｃｂ．得到了这种复合算子属于Ｓｃｈａｔｔｅｎ－Ｖｏｎ Ｎｅｕｍａｎｎ理想Ｓｐ的几个充要条件．     

非线性Lipschitz算子的Lipschitz对偶算子及其应用

在文山中我们对非线性Ｌｉｐｓｃｈｉｔｚ算子定义了其Ｌｉｐｓｃｈｉｔｚ对偶算子，并证明了任意非线性Ｌｉｐｓｃｈｉｔｚ算子的Ｌｉｐｓｃｈｉｔｚ对偶算子是一个定义在Ｌｉｐｓｃｈｉｔｚ对偶空间上的有界线性算子．本文还进一步证明：设Ｃ为 Ｂａｎａｃｈ空间 Ｘ的闭子集，Ｃ＊Ｌ为Ｃ的 Ｌｉｐｓｃｈｉｔｚ对偶空间，Ｕ为 Ｃ＊Ｌ上的有界线性算子，则当且仅当 Ｕ为 ｗ＊－ｗ＊连续的同态变换时，存在Ｌｉｐｓｃｈｉｔｚ连续算子Ｔ，使Ｕ为Ｔ的Ｌｉｐｓｃｈｉｔｚ对偶算子．这一结论的理论意义在于：它表明一个非线性Ｌｉｐｓｃｈｉｔｚ算子的可逆性问题可转化为有界线性算子的可逆性问题．作为应用，通过引入一个新概念──ＰＸ－对偶算子，在一般框架下给出了非线性算子半群的生成定理．     

Bergman空间上Hankel算子的本性范数的刻划

在文中,对于Ｃ＾ｍ中有界强拟凸域Ω,得到了Ｂｅｒｇｍａｎ空间Ａ＾２（Ω）上的Ｈａｎｋｅｌ算子Ｈｆ（ｆ∈Ｌ＾２（Ω,ｄｖ）的本性范数∥Ｈｆ∥ｅｓｓ（在Ｌ＾２（Ω,ｄｖ上）的等价刻划。     

核局部凸空间的一个新特征

Ａ．Ｐｉｅｔｓｃｈ＾［１］在讨论核局部凸空间时给出了两类矢值序列空间ｌ１［Ｘ］和ｌ１｛Ｘ｝。本文建立了矢值序列空间ｌ１［Ｘ］及ｌ１｛Ｘ｝和连续线性算子空间Ｌ（ｃ０，Ｘ）及绝对可和算子空间ＡＳ（ｃ０，Ｘ）之间的拓扑同胚关系。通过ｃ０上的矢值算子类Ｌ（ｃ０，Ｘ）和ＡＳ（ｃ０，Ｘ）及其上的拓扑等价关系，对局部凸空间Ｘ是核空间给出了一个新的特征刻划。     

Hermite型插值算子对可微函数的逼近

Ｈｅｒｍｉｔｅ型插值算子对可微函数的逼近章仁江（中国计量学院，杭州３１００３４）关键词Ｈｅｒｍｉｔｅ型插值算子，Ｊａｃｏｂｉ多项式．分类号ＡＭＳ（１９９１）４１Ａ／ＣＣＬＯ１７４设（１）＞ｘ１＞ｘ２＞…＞ｘｎ＞（－１），ｘｋ＝ｃｏｓθｋ（ｋ＝１，２，...     

Cm空间中非线性Lipschitz连续算子的定量性质

在有限维复Banach空间C     

解析算子值函数的Riesz—Dunford积分

1.引言 设H为复Hilbert空间,L(H)表示H上所有连续线性算子组成的Banach空间。若f(z)为定义在复平面区域D上的算子值函数,f(z)∈L(H)(z∈D),我们称f(z)于D上解析,是指对L(H)上的每个连续线性泛函φ,φ(f(z))为D上通常的复值解析函数,其全体记为A_H(D)。令     

关于p-弱亚正规算子的一个注记

对0相似文献   

Hausdorff operators on Euclidean spaces

Hausdorff operator is an important operator raised from the dilation on Euclidean space and rooted in the classical summability of number series and Fourier series. It is also connected to many well known operators in real and complex analysis. This article is a survey of some recent developments and extensions on the Hausdorff operator. Particularly, various boundedness properties of the Hausdorff operators, studied recently by our research group, are addressed.     

Definitizability of a Class of J-Selfadjoint Operators with Applications

We formulate an abstract result concerning the definitizability of J-selfadjoint operators which, roughly speaking, differ by at most finitely many dimensions from the orthogonal sum of a J-selfadjoint operator with finitely many negative squares and a semibounded selfadjoint operator in a Hilbert space. The general perturbation result is applied to a class of singular Sturm–Liouville operators with indefinite weight functions. (© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Orlicz空间上的乘法算子

函数空间上的乘法算子是包含许多重要算子的算子类,该文主要研究Orlicz空间上乘法算子的一系列重要性质,包括有界性、紧性、Fredholm性质以及谱的计算等     

Spectral structure of the Neumann–Poincaré operator on tori

We address the question whether there is a three-dimensional bounded domain such that the Neumann–Poincaré operator defined on its boundary has infinitely many negative eigenvalues. It is proved in this paper that tori have such a property. It is done by decomposing the Neumann–Poincaré operator on tori into infinitely many self-adjoint compact operators on a Hilbert space defined on the circle using the toroidal coordinate system and the Fourier basis, and then by proving that the numerical range of infinitely many operators in the decomposition has both positive and negative values.     

Dirichlet型空间上Toeplitz算子的本性范数

本文研究单位圆盘上Dirichlet型空间非紧Toeplitz算子的本性范数, 它事实上等于到紧Toeplitz算子集的距离. 并且这个距离可由无限多个紧Toeplitz算子来刻画, 这个结果与加权Bergman空间情形的类似.     

Adjoints of linear fractional composition operators on the Dirichlet space

The adjoint of a linear fractional composition operator acting on the classical Dirichlet space is expressed as another linear fractional composition operator plus a two rank operator. The key point is that, in the Dirichlet space modulo constant functions, many linear fractional composition operators are similar to multiplication operators and, thus, normal. As a particular application, we can easily deduce the spectrum of each linear fractional composition operator acting on such spaces. Even the norm of each linear fractional composition operator is computed on the Dirichlet space modulo constant functions. It is also shown that all this work can be carried out in the Hardy space of the upper half plane.This work was partially supported by Plan Nacional I+D Ref. BFM2000-0360 and Junta de Andalucía Ref. FQM-260. The first named author was also supported by Plan Propio de la Universidad de Cádiz.