树上p-Laplacian算子的第一混合特征值

本文研究了树上以唯一根为Dirichlet边界的离散加权p-Laplacian算子的第一特征值问题,该特征值亦为一类加权Hardy不等式的最优常数.通过研究此特征值对应的特征函数的性质,给出具有混合边界的特征值的三种变分公式,该结果可以看做经典变分公式的重要补充.作为应用,给出了此特征值的上、下界的基本估计,并给用两个例子例证相关结果.     

Heisenberg-Greinerp-退化椭圆算子的广义Picone恒等式及其应用

该文建立了Heisenberg-Greiner p-退化椭圆算子的广义Picone恒等式.作为应用,给出了Hardy不等式、Sturmium比较原理和主特征值的单调性结论.最后,讨论了具有奇异项的拟线性方程的弱解问题.     

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.     

p=5/4时Hardy不等式的一个改进

在Hardy不等式的研究中,引入权系数并对其进行改进,是行之有效的办法.随着权系数构造的不同,所建立的不等式也将出现强弱之分.针对Hardy不等式的一个加强式展开讨论,通过对新的权系数的估计,建立了Hardy不等式的进一步改进,相比于现有结论,所建立的不等式较优.     

Calderón-Zygmund算子在H_b~p空间上的有界性

众所周知,如果Calderón-Zygmund算子T满足T~*(1)=0,则算子T在H~p,n/(n+ε)相似文献   

一类新型Szasz-Kantorovich-Bezier算子在Orlicz空间内的逼近

研究了一类新型Szasz-Kantorovich-Bezier算子在Orlicz空间内的逼近问题.在连续函数空间和L_p空间内研究算子逼近方法的基础上,利用函数逼近论中的常用方法和技巧以及K泛函、Ditzian-Totik模、Holder不等式、Cauchy不等式、凸函数的Jensen不等式等工具得到了该算子在Orlicz空间内的逼近正定理、逆定理和等价定理.由于Orlicz空间包含连续函数空间和L_p空间,其拓扑结构也比L_p空间复杂得多,所以本文的结果具有一定的拓展意义.     

Heisenberg型群上一类精确Hardy型不等式和Hardy-Sobolev型不等式及应用(英文)

本文在Heisenberg型群上建立了一类精确的Hardy型不等式。采用的技巧是逼近及正则化的方法。进一步利用这个结果,本文建立了一类精确的Hardy-Sobolev型不等式。这两个结果包括了已有的相关结果。作为应用,讨论了一类具有Hardy位势的非线性算子的正定性与下无界性。     

一维Hardy型不等式注记

本文通过H?lder不等式、单调性等技巧证明了一些新的一维Hardy型不等式,这些不等式在某种程度上推广了现有的一维Hardy型不等式.     

从Hardy空间到Bloch空间的Volterra型复合算子

本文研究了从Hardy空间到Bloch型空间的Volterra型复合算子的有界性和紧性问题,事实上,我们给出了该算子的范数和本性范数刻画.同时我们研究了从Hardy空间到小Bloch型空间的Volterra型复合算子的有界性和紧性问题.     

带Robin边值条件的半线性奇异椭圆方程正解的存在性

本文研究了一类带Robin边值条件的半线性奇异椭圆方程．通过Hardy不等式，山路引理以及选取适当的试验函数验证局部PS条件，得到了此类方程正解的存在性这一结果．     

二维p-级数域上二进求导极大算子(英文)

本文研究二维情况下p-级数域上二进求导极大算子的有界性. 利用狄利克雷核的重要性质, 构造反例证明此极大算子不是从Hardy空间Hq到Hardy空间Hq有界的, 其中0 < q ≤ 1. 此结果完善了Walsh群上的已有结论.     

2维二进求导极大算子的有界性

本文研究了二进求导极大算子的有界性.利用狄利克雷核的重要性质,构造了反例证明此极大算子在一维和二维情况下都不是从Hardy空间Hp到Hardy空间Hp有界的,其中0相似文献   

Atomic Decompositions of Hardy Spaces with Variable Exponents and its Application to Bounded Linear Operators

As applications of atomic decomposition results of Hardy spaces with variable exponents, we shall prove the boundedness of commutators and the fractional integral operators as well as the Hardy operators. There are many ways to prove such boundedness. For example, the boundedness of commutators can be proved by the sharp maximal inequalities. But here, we propose a different method based upon our atomic decomposition.     

Approximate Factorization in Generalized Hardy Spaces

In this paper we establish a connection between the approximate factorization property appearing in the theory of dual algebras and the spectral inclusion property for a class of Toeplitz operators on Hilbert spaces of vector valued square integrable functions. As an application, it follows that a wide range of dual algebras of subnormal Toeplitz operators on various Hardy spaces associated to function algebras have property (A ₁(1)). It is also proved that the dual algebra generated by a spherical isometry (with a possibly infinite number of components) has the same property. One particular application is given to the existence of unimodular functions sitting in cyclic invariant subspaces of weak* Dirichlet algebras. Moreover, by this method we provide a unified approach to several Toeplitz spectral inclusion theorems. Research partially supported by grant CNCSIS GR202/2006 (cod 813).     

Two classroom proofs concerning composition operators

We consider composition operators on spaces of analytic functions. First we give an elementary proof for the well-known fact that these operators are bounded on the usual Hardy spaces. Then, for more general spaces, we give two results concerning the question when composition operators are injective or onto, and get a complete answer for a class of spaces, including the Hardy spaces.     

Log-Sobolev inequalities for semi-direct product operators and applications

In this paper, we prove some type of logarithmic Sobolev inequalities (with parameters) for operators in semi-direct product forms (see Sect. 1 for a precise definition). This generalizes the tensorization procedure for this type of inequalities and allows to deal with some operators with varying coefficients. We provide many examples of applications and obtain ultracontractive bounds for some of these operators by using appropriate Hardy’s type inequalities necessary for our method. This theory is developed in the setting of carré du champ with diffusion property.     

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.     

Interpolation of Operators on Scales of Generalized Lorentz-Zygmund Spaces

We define generalized Lorentz-Zygmund spaces and obtain interpolation theorems for quasilinear operators on such spaces, using weighted Hardy inequalities. In the limiting cases of interpolation, we discover certain scaling property of these spaces and use it to obtain fine interpolation theorems in which the source is a sum of spaces and the target is an intersection of spaces. This yields a considerable improvement of the known results which we demonstrate with examples. We prove sharpness of the interpolation theorems by showing that the constraints on parameters are necessary for the interpolation theorems.