一类新型非正规算子的谱分析

本文引入了一类新型非正规算子,即具复谱的u-标算子.证明了该类算子具有Jordan型分解,讨论了u-标算子与标型谱算子的关系,并通过例子说明了该类算子的构造.     

Dirichlet型空间上Hankel算子和乘法算子

本文讨论了Dirichlet型空间上的再生核,并对Dirichlet型空间上乘法算子,Hankel算子和小Hankel算子的基本性质进行了研究,同时也给出了这些算子的有界性,紧性和Schatten理想的初步刻画。     

Dirichlet空间上Toeplitz算子与Berezin型变换相关的一些性质

本文研究了单位圆盘D 的Dirichlet 空间上Toeplitz 算子和小Hankel 算子. 利用Berezin 型变换讨论了Toeplitz 算子的不变子空间问题, 具有Berezin 型符号的Toeplitz 算子的渐进可乘性以及Toeplitz 算子的Riccati 方程的可解性. 应用Berezin 变换得到了Toeplitz 算子和小Hankel 算子可逆的充分条件. 此外, 还利用Hankel 算子和Berezin 变换刻画了算子2T_uv-T_uT_v-T_vT_u 的紧性, 其中函数u,v ∈ L^2,1.     

Boundedness and compactness of Volterra type integral operators

We introduce some nested classes of Volterra type integral operators. For the operators of these classes we establish criteria for boundedness and compactness in Lebesgue spaces.     

齐型空间上的一类积分算子

在齐型空间上讨论由分数次积分算子、奇异积分算子及ＢＭＯ函数所构成的几类Ｔｏｅｐｌｉｔｚ型算子的有界性．     

Volterra型算子和复合算子乘积的有界性

本文研究了从上半平面的Hardy空间到Zygmund空间上的Volterra型算子和复合算子乘积的有界性问题.利用泛函分析和复分析的方法,获得了从上半平面的Hardy空间到Zygmund空间生成的Volterra型算子和复合算子的乘积有界性刻画,推广了S.Stevic关于从上半平面的Hardy空间到Zygmund空间上的复合算子有界性的结果.     

WEIGHTED ESTIMATES FOR COMMUTATORS OF POTENTIAL OPERATORS ON SPACES OF HOMOGENEOUS TYPE

We derive some strong type and weak type weighted norm estimates which relate the commutators of potential integral operators to the corresponding maximal operators in the context of spaces of homogeneous type.     

A relation between convolution type operators on intervals in sobolev spaces

We construct an operator relation between convolution type operators with or without a reflection on a union of finite intervals and corresponding Wiener-Hopf operators. This relation is the reult for several other relations between intermediate operators constructed for that purpose. The presented relations are obtained with the help of different extension methods that annulate particular actions of the related operators. All the operators are defined in Bessel potential spaces or Sobolev spaces. In particular, the final relation enables us to derive properties from a Wiener-Hopf operator to the intial one. An example of application of the presented results is done in a differaction problem by a union of two strips     

Boundedness of Toeplitz Type Operators Associated to Fractional and Pseudo-Differential Operators on Orlicz Space

In this paper, the boundedness from Lebesgue space to Orlicz space of certain Toeplitz type operator related to the fractional and pseudo-differential operators is obtained.     

Schatten-Herz type positive Toeplitz operators on pluriharmonic Bergman spaces

Recently, Schatten-Herz type Toeplitz operators have been studied on the Bergman spaces and the harmonic Bergman spaces. Motivated these results, we study characterizations of positive Toeplitz operators of Schatten-Herz type in terms of averaging functions and Berezin transforms of symbol functions on the ball of pluriharmonic Bergman spaces.     

A fredholm study for convolution operators with piecewise continuous symbols on a union of a finite and a semi-infinite intervel 1

We study convolution type operators with kernels that have Fourier transforms in the class of piecewise continuous matrix functions. These convolution operators are assumed to act between Sobolev spaces defined on a union of a finite and a semi-infinite intervel. The main result is a criterion for the Fredholm property of these operators. An application to a problem related to diffraction theory is illustrated.     

与分数次积分和具有非光滑的奇异积分算子相关的Toeplitz型算子在Morrey空间的有界性

本文证明了与分数次积分和具有非光滑的奇异积分算子相关的Toeplitz型算子的sharp极大函数估计,做为应用,得到了该算子在Morrey空间的有界性.     

次线性算子在Herz型Hardy空间上的有界性

本文得到了一类次线性算子在Herz型Hardy空间上的有界性判定条件,该算子包括调和分析中许多重要的算子,同时还证明了Bochner-Riesz算子在Herz型Hardy空间上的有界性.     

WEIGHTED L~p-APPROXIMATION BY THE MODIFIED NEVAI OPERATORS

The present paper gives a Jackson type estimate for Nevai operators under weighted Lp norm, and establishes the direct and converse theorems in some proper Besov spaces.     

A Cotlar type inequality for the multilinear singular integral operators and its applications

A Cotlar type inequality is established for the multilinear singular integral operators. As applications, some two-weight norm inequalities are obtained for the maximal operator corresponding to the multilinear singular integral operators.     

圆环上的Hankel与Toeplitz型算子

令Ω是复平面上的圆环 ,则L2 (Ω) = ∞-∞Ak = ∞-∞ Ak 为其正交直和分解 .本文中我们定义了一类Hankel和Toeplitz型算子 ,研究了它们的紧性和Sp 性质 .     

Multilinear fractional Hausdorff operators

In this paper,by introducing the space with weak mixed norms,weak type estimates of two kinds of multilinear fractional Hausdorff operators RΦ,β and SΦ,β on Lebesgue spaces are shown.By virtue of Marcinkiewicz interpolation,strong type estimates of these two operators on Lebesgue spaces are also obtained.Our methods shed some new light on dealing with the case of non-radial function Φ.     

Durrmeyer type modification of generalized Baskakov operators

In the present paper, Durrmeyer type modification of generalized Baskakov operators is introduced and some direct results are established for these operators.     

WEAK TYPE INEQUALITIES FOR FRACTIONAL INTEGRAL OPERATORS ON GENERALIZED NON-HOMOGENEOUS MORREY SPACES

We obtain weak type (1,q) inequalities for fractional integral operators on generalized non-homogeneous Morrey spaces.The proofs use some properties of maximal operators.Our results are closely related to the strong type inequalities in [13,14,15].     

更一般的常系数线性差分微分方程的解

利用Mikusinski J的算符演算,移动算符级数和微分算符的有关公式,给出更为一般的低阶常系数线性差分微分方程的级数形式解.