Duality results and inequalities with respect to Hardy spaces containing function sequences

With the help of two-parameter martingales and strong martingales Hardy spaces consisting of adapted function sequences are considered. The Hardy spaces generated by the square and by the conditional square functions and their dual spaces are investigated. An inequality due to Stein and Lepingle is extended to two parameters.This research was supported by the Hungarian Scientific Research Funds No. 2085 and No. 74189 as well as by DAAD, the lattest with a stay at the Ludwig-Maximilians-Universität in München.     

强奇异卷积算子交换子的Hardy型空间估计

本文给出了强奇异卷积算子交换子[6,T]在Hardy型空间中的估计,其中 b∈BMO(Rn)且一致连续, T为强奇异卷积算子.     

Some weighted estimates for Littlewood-Paley functions and radial multipliers

We prove some weighted estimates for certain Littlewood-Paley operators on the weighted Hardy spaces H_w^p (0<p?1) and on the weighted L^p spaces. We also prove some weighted estimates for the Bochner-Riesz operators and the spherical means.     

在Hp空间上的函数准解析类

对包含在Hp空间上的函数准解析类Hp(Mn)的准解析问题给出了解答,这个解答与经典的Denjoy-Carleman准解析和Mandelbrojt准解析问题的解答相类似.     

Concentration at a radius for Hardy class functions

In this paper we establish the fundamental properties of concentration at a radius for functions in the classical Hardy space on the unit disk. For f(z) which is not identically zero and given r, 0<r<1, the concentration is defined via the ratio of the norm of f(rz) to the norm of f(z). Using the Mahler measure of f(z), we obtain information on the distribution of the zeros of f(z) in terms of the concentration ratio. In the last section of the paper, we examine the sharpness of concentration estimates for the Blaschke factor.     

Estimates of Oscillations of the Hardy Transform

For the Hardy transform of a nonincreasing function we obtain a sharp two-sided estimate of the BLO-norm and sharp inequalities between the BMO- and the BLO-norms of a nonincreasing function. A well-known lower bound for the BMO-norm of the Hardy transform is improved on the basis of these inequalities.     

Elliptic problems with critical exponents and Hardy potentials

This paper is devoted to the existence of positive solutions of a Dirichlet problem with critical exponent and a singular potential. Under various assumption on the domain Ω, which include some kinds of unbounded domains, we prove the existence of ground states and of symmetric solutions.     

Hp(Ωn)(0＜p＜1)上临界阶Riesz平均强求和的逼近

本文讨论了球面上Hardy空间Hp(0＜p＜1)中Riesz平均的强求和在临界阶δ=n/p-n+1/2的有界性,并且建立了它和最佳逼近之间的关系.