局部紧Vilenkin群上权BMOα空间与奇异积分

已有一些论文讨论局部域上奇异积分关于Lebesgue空间,Hardy空间及BMO空间上的有界性,本文讨论了局部紧Vilenkin群上一类奇异积分的权BMOα空间的有界性。给出了主值奇异积分的BMOα空间的有界性定理。     

粗糙核超奇异积分算子的加权有界性

利用Fourier变换和Littlewood-Paley理论,讨论了带粗糙核的超奇异积分算子的加权有界性．证明了带粗糙核的超奇异积分算子从Sobolev空间到Lebesgue空间的有界性．     

带粗糙核的奇异积分交换子的有界性

本文研究了带粗糙核的奇异积分算子与BMO函数生成的交换子的有界性问题.利用原子分解的方法,获得了带粗糙核的奇异积分交换子TΩb在Lp空间、Hardy空间、弱Hardy空间上的有界性结果,推广了交换子Tb在各类函数空间上有界性的结果.     

一些奇异积分算子的有界性

本文首先讨论由 R.Fefferman[1]引进的奇异积分算子在更弱的条件下的 L~p(1相似文献   

混合勒贝格空间上双参数奇异积分算子的端点弱估计（英文）

本文研究了混合勒贝格空间上双参数奇异积分算子的有界性.利用双参数奇异积分算子在勒贝格空间的有界性和一个向量值延拓理论.获得了双参数奇异积分算子在混合勒贝格空间上的端点弱估计和强型估计.并给出了乘积空间上非卷积型奇异积分算子的一个应用.这些结果将文献[3]中的结论推广到混合范数情形.     

沿复合子簇的粗糙核极大算子

给出了两类相关于沿复合子簇的粗糙核奇异积分的极大算子的L~p有界性,本质上极大地改进和一般化了已有的结果.作为应用,相关的奇异积分,Marcinkiewicz积分和相应的极大算子的L~p有界性也被建立.     

Theta(t)型奇异积分算子在Banach空间值上的加权有界性

本文借助于Calderón-Zygmund分解理论和Hardy空间的原子分解理论,把实值上的几个结果推广到了Banach值的情形,得到了theta(t)型奇异积分算子在Banach值加权空间上的有界性,以及在Banach值加权Hardy空间上的有界性.这些结果是theta(t)型奇异积分算子有界性的完善和补充.     

一类粗糙奇异积分的加权Triebel-Lizorkin有界性

本文研究了一类粗糙奇异积分算子的加权Triebel-Lizorkin有界性.对核函数Ω∈Llog L(Sn-1)建立了径向权函数的加权有界性;而对于核函数Ω∈Lr(Sn-1),1相似文献   

θ-型Calderón-Zygmund算子交换子的端点加权估计

讨论了θ-型奇异积分算子交换子在Hardy空间的加权有界性.     

一类粗糙奇异积分的加权 Triebel-Lizorkin有界性

本文研究了一类粗糙奇异积分算子的加权Triebel-Lizorkin有界性.对核函数Ω∈L log+L(Sn-1)建立了径向权函数的加权有界性;而对于核函数Ω∈Lr(Sn-1),1＜r≤∞,得到了一般的Muckenhopt权函数的加权有界性.     

RECENT PROGRESS ON SPHERICAL HARMONIC APPROXIMATION MADE BY BNU RESEARCH GROUP ——In memory of Professor Sun Yongsheng

As early as in 1990, Professor Sun Yongsheng, suggested his students at Beijing Normal University to consider research problems on the unit sphere. Under his guidance and encouragement his students started the research on spherical harmonic analysis and approximation. In this paper, we incompletely introduce the main achievements in this area obtained by our group and relative researchers during recent 5 years （2001-2005）. The main topics are： convergence of Cesaro summability, a.e. and strong summability of Fourier-Laplace series; smoothness and K-functionals; Kolmogorov and linear widths.     

A unified approach to certain problems of best local approximation

In this paper we study best local quasi-rational approximation and best local approximation from finite dimensional subspaces of vectorial functions of several variables. Our approach extends and unifies several problems concerning best local multi-point approximation in different norms.     

Boundedness for commutators of multipliers on Hardy type spaces

In this paper, we study the commutators generalized by multipliers and a BMO function. Under some assumptions, we establish its boundedness properties from certain atomic Hardy space Hb^p（R^n） into the Lebesgue space L^p with p 〈 1.     

THE 8~(th) INTERNATIONAL CONGRESS ON INDUSTRIAL AND APPLIED MATHEMATICS

<正>August 10-14,2015Beijing,ChinaThe International Congress on Industrial and Applied Mathematics(ICIAM)is the premier international congress in the field of applied mathematics held every four years under the auspices of the International Council for Industrial and Applied Mathematics.From August 10 to 14,2015,mathematicians,scientists     

Towards Excellence in Science Chinese Academy of Sciences

<正>May 26,2014,Beijing Science is a human enterprise in the pursuit of knowledge.The scientific revolution that occurred in the 17th Century initiated the advances of modern science.The scientific knowledge system created by     

Bounds for the zeros of polynomials

Let P(z)=∑↓j=0↑n ajx^j be a polynomial of degree n. In this paper we prove a more general result which interalia improves upon the bounds of a class of polynomials. We also prove a result which includes some extensions and generalizations of Enestrǒm-Kakeya theorem.     

Boundedness of commutators related to Marcinkiewicz integrals on hardy type spaces

In this paper, the authors study the boundedness of the operator [μΩ, b], the commutator generated by a function b ∈ Lipβ(Rn)(0 ＜β≤ 1) and the Marcinkiewicz integrals μΩ, on the classical Hardy spaces and the Herz-type Hardy spaces in the case Ω∈ Lipα(Sn-1)(0 ＜α≤ 1).     

Jacobi polynomials used to invert the laplace transform

Given the Laplace transform F(s) of a function f(t), we develop a new algorithm to find an approximation to f(t) by the use of the classical Jacobi polynomials. The main contribution of our work is the development of a new and very effective method to determine the coefficients in the finite series expansion that approximation f(t) in terms of Jacobi polynomials. Some numerical examples are illustrated.     

Generalization of the interaction between Haar approximation and polynomial operators to higher order methods

In applications it is useful to compute the local average empirical statistics on u. A very simple relation exists when of a function f（u） of an input u from the local averages are given by a Haar approximation. The question is to know if it holds for higher order approximation methods. To do so, it is necessary to use approximate product operators defined over linear approximation spaces. These products are characterized by a Strang and Fix like condition. An explicit construction of these product operators is exhibited for piecewise polynomial functions, using Hermite interpolation. The averaging relation which holds for the Haar approximation is then recovered when the product is defined by a two point Hermite interpolation.