底空间为对称域乘积的Hartogs域的度量等价

研究一类非齐性Hartogs域上经典度量的等价问题.首先证明了Bergman-度量和Einstein-Khler度量在这类域上等价;其次,当域的参数满足mσ+nΤ<1时,此类域上Bergman度量,Carathéodary度量,Kobalyashi度量和Einstein-Khler度量是等价的.     

第一类超 Cartan域上的比较定理

给出了第一类超Cartan域上不变Kähler 度量下的全纯截曲率的表达式.利用其Bergman度量的完备性,构造了一个不比Bergman度量小的完备的不变Kähler度量.证明了在此Kähler度量下的全纯截曲率有一个负上界, 从而证明了第一类超Cartan域的Bergman度量和Kobayashi度量的比较定理.     

Cartan-Hartogs域经典度量的等价

研究华罗庚域的特殊类型即第1类Cartan-Hartogs域的不变完备度量.首先找到了一种新的不变完备度量, 证明它们与Bergman度量等价; 第2,证明这些新的度量的Ricci曲率具有负的上下界;第3,我们证明了新的度量的全纯截曲率有 负的上下界; 最后,通过新的完备度量作为过渡, 并利用丘成桐的Schwarz引理,证明了第1类Cartan-Hartogs域的Bergman度量和Einstein-Kähler度量是等价的,也就是说丘成桐猜想在第1类Cartan-Hartogs域上成立.对其他几类的Cartan-Hartogs也有类似的结果.     

超Cartan域的Einstein-K(a^)hler度量

给出了第1类超Cartan域的Einstein-K(a^)hler度量生成函数的隐函数表达式;给出了第1类超Cartan域的全纯截曲率及其估计,并由此对K＞mn-1时的第1类超Cartan域给出了Einstein-Kaihler度量和Kobayashi度量的比较定理;对一种特殊的超Cartan域给出了其完备的Einstein-K(a^)hler度量的显表达式,这在非齐性域中还是首次得到.     

Cartan-Hartogs域上Kaihler-Einstein度量与Bergman度量的等价

本文研究的是华罗庚域的特殊类型第二类Cartan-Hartogs域的不变Bergman度量与Kahler-Einstein度量的等价问题．引入一种与Bergman度量等价的新的完备的Kahler度量ωgλ，其Ricci曲率和全纯截取率具有负的上下界．然后应用丘成桐对Schwarz引理的推广证明ωgλ等价于Kahler-Einstein度量，从而得到了Bergman度量与Kahler-Einstein度量的等价，即丘成桐关于度量等价的猜想在第二类Cartan-Hartogs域上成立．     

第四类超Cartan域上的比较定理

本文得到了第四类超Cartan域上的Bergman度量和Kobayashi度量的比较定理．     

Caftan-Hartogs域上K(a)hler-Einstein度量与Bergman度量的等价

本文研究的是华罗庚域的特殊类型第二类Cartan-Hartogs域的不变Bergman度量与Kahler-Einstein度量的等价问题.引入一种与Bergman度量等价的新的完备的Kahler度量ωgλ,其Ricci曲率和全纯截取率具有负的上下界.然后应用丘成桐对Schwarz引理的推广证明ωgλ等价于Kahler-Einstein度量,从而得到了Bergman度量与Khhler-Einstein度量的等价,即丘成桐关于度量等价的猜想在第二类Cartan-Hartogs域上成立.     

第三类超Cartan域上的比较定理

本文给出了第三类超Cartan域上不变Kalher度量下的全纯截曲率的表达式.利用其Bergman度量的完备性,构造了一个不比Bergman度量小的完备的不变Kalher度量,证明了在此Kalher度量下的全纯截曲率有一个负上界,从而证明了第三类超Cartan域的Bergman度量与Kobayashi度量的比较定理.     

多复变Hartogs域上的度量与刚性

本文主要涉及几类多复变Hartogs域上的度量与刚性.首先讨论有界对称域上的Hartogs域与其典则度量相关的加权Bergman核的展开式以及该典则度量为平衡度量的充要条件.其次给出几类多复变Hartogs域(如华罗庚域、Fock-Bargmann-Hartogs域和五面块(pentablock))上逆紧全纯映射的刚性结果.     

第一类超Cartan域上的不变度量

首先证明超Cartan域Y_I(k;N;m,n)为凸域的充分必要条件是2k■m;接着讨论了在超Cartan域上四类经典的不变度量,即Bergman度量、Caratheodory度量、Kobayashi度量和Einstein-Kahler度量的等价性;最后通过计算得到了超Cartan域Y_I(1;N;2,n)和Y_I(2;N;2,n)上的Caratheodory度量(和Kobayashi度量)的显表达式.     

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.     

Instructions for Authors

<正>Submission Authors must use LaTeX for typewriting,and visit our website www.actamath.com to submit your paper.Our address is Editorial Office of Acta Mathematica Sinica,Academy of Mathematics and Systems Science,Chinese Academy of Sciences,Beijing 100190,P.R.China.     

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

正August 10-14,2015Beijin,China The 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     

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.     

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.     

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     

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     

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.