高维空间的拟正则映照

将所有维数的 Beltrami方程组 Dtf· Df =J2 /n G化为一个“Beltrami方程”并利用它研究了 Bel-trami方程组的解的正则性 ,得到一个比文献 [8]更大的正则性区间 .     

一类整系数多项式的不可约性与有理根存在性的判别

根据整系数多项式的系数所满足的条件,判定其分解式的唯一性和因式的不可约性,有理根的存在性,以及它们与给定多项式的不可约性的关系.     

极值Beltrami系数的Hamilton序列

考虑了Strebel点与Hamilton序列之间的关系.这个问题是Gardiner F.P.最早研究的(见[Approximation of infinite-dimensional Tcichmiiller spaces,Trans.Amer.Math.Soc.,1984,282(1):367-383]).在无限小Teichmiiller空间中,证明了范金华在[On infinitesimal Teichmüller space,Bull.Austral Math.Soc.,2008,78:293-300]中得到的使{φ_n}成为Hamilton序列的充分条件不是必要的.     

Beltrami流动的球涡解的张量表示及其对称性分析

讨论了一类Beltrami流动的n阶球涡（非轴对称及轴对称）的张量表示及由此引出的对其的分类和对称性的研究，还进一步地讨论了单个此类非轴对称n阶球涡解的混沌现象；从另一侧面说明了非轴对称Beltrami流动的球涡解的复杂性及多样性，以及用张量表示的更广泛的内涵。     

具有不可缩伸缩商的拟共形映射

在研究拟共形映射的唯一极值性时,Reich引入了具有不可缩伸缩商的拟共形映射的概念.本文将继续讨论这类映射,并给出无穷小情形下的一些类似结果     

具有不可缩伸缩商的拟共形映射

在研究拟共形映射的唯一极值性时,Reich引入了具有不可缩伸缩商的拟共形映射的概念.本文将继续讨论这类映射,并给出无穷小情形下的一些类似结果.     

On a relation between the universal Teichmüller space and the Grunsky operator

Being a Strebel point gives a sufficient condition for that the extremal Beltrami coefficient is uniquely determined in a Teichmiiller equivalence class. We consider how Strebel points are characterized. In this paper, we will give a new characterization of Strebel points in a certain subset of the universal Teichmfiller space by a property of the Grunsky operator.     

再论整数环上多项式的不可约性的判别法

本研究整系数多项式的不可约因式，给出了低次不可约多项式的判别的一种方法和一些不可约问题的处理方法。     

Beltrami定理的推广

本文研究了Berwald流形之间的射影对应.利用Berwald流形上Weyl射影曲率张量的射影不变性,证明了当n>2时,与射影平坦的Berwald流形射影对应的黎曼流形M~n是常曲率流形,从而推广了Beltrami定理.     

多项式的值与多项式不可约

在判定整系数多项式是否在有理数域Q上不可约时,一般用系数的性质来判定。实际上多项式的值与不可约性有着密切的联系。Brow和Graha证明了:设f(x)是n次整系数多项     

On characterizations of unique extremality

In this paper, we make some further considerations of the characteristic conditions of (infinitesimally) unique extremality for Beltrami coefficients obtained by Bozin et al., and find some sufficient conditions simpler in form for a Beltrami coefficient μ with nonconstant absolute value to be (infinitesimally) uniquely extremal.     

On Bloch functions and the Contraction of Teichmüller metrics

In this note, we consider the properties of Bloch functions derived by Beltrami coefficient. A sufficient condition for extremal quasiconformal mapping with nonexistence of degenerating sequence is obtained. As a result, we consider the contraction or preserved of Teichmüller metrics for the related Beltrami lines under the projection mapping π     

Historical origins of the nine-point conic. The contribution of Eugenio Beltrami

In this paper, we examine the evolution of a specific mathematical problem, i.e. the nine-point conic, a generalisation of the nine-point circle due to Steiner. We will follow this evolution from Steiner to the Neapolitan school (Trudi and Battaglini) and finally to the contribution of Beltrami that closed this journey, at least from a mathematical point of view (scholars of elementary geometry, in fact, will continue to resume the problem from the second half of the 19th to the beginning of the 20th century). We believe that such evolution may indicate the steady development of the mathematical methods from Euclidean metric to projective, and finally, with Beltrami, with the use of quadratic transformations. In this sense, the work of Beltrami appears similar to the recent (after the anticipations of Magnus and Steiner) results of Schiaparelli and Cremona. Moreover, Beltrami's methods are closely related to the study of birational transformations, which in the same period were becoming one of the main topics of algebraic geometry. Finally, our work emphasises the role played by the nine-point conic problem in the studies of young Beltrami who, under Cremona's guidance, was then developing his mathematical skills. To this end, we make considerable use of the unedited correspondence Beltrami – Cremona, preserved in the Istituto Mazziniano, Genoa.     

Asymptotics of solutions to the Laplace–Beltrami equation on a rotation surface with a cusp

In this work we study an asymptotic behaviour of solutions to the Laplace–Beltrami operator on a rotation surface near a cuspidal point. To this end we use the WKB-approximation. This approach describes the asymptotic behaviour of the solution more explicitly than abstract theory for operators with operator-valued coefficients.     

A note on Hamilton sequences for extremal Beltrami coefficients

F. P. Gardiner gave a sufficient condition for a sequence to be a Hamilton sequence for an extremal Beltrami coefficient. In this note, we shall consider the converse problem, proving that the condition is not necessary.

     

关于双特征Beltrami方程

该文研究空间Ｂｅｌｔｒａｍｉ方程的推广形式，即双特征Ｂｅｌｔｒａｍｉ方程．利用外微分形式与矩阵的外代数等工具，将双特征Ｂｅｌｔｒａｍｉ方程转化为一个非齐次的狆 调和方程，转化过程中只用到加于特征矩阵的一致椭圆型条件．然后验证了算子犃满足的条件：Ｌｉｐｓｃｈｉｔｚ型条件、单调不等式、齐次性条件以及算子犅满足的控制增长条件．并利用得到的狆 调和方程，给出了双特征Ｂｅｌｔｒａｍｉ方程广义解分量函数的弱单调性结果．     

Some characterizations of unique extremality

In this paper, it is shown that some necessary characteristic conditions for unique extremality obtained by Zhu and Chen are also sufficient and some sufficient ones by them actually imply that the uniquely extremal Beltrami differentials have a constant modulus. In addition, some local properties of uniquely extremal Beltrami differentials are given.     

1-quasiconformal mappings on a （2,2）-type quadric

This paper gets the Beltrami equations satisfied by a 1-quasiconformal mapping, which are exactly CR or anti-CR equations on （2,2）-type quadric Q0. This means a 1-quasiconformal mapping on Q0 is CR or anti-CR. This reduces the determination of 1- quasiconformal mappings to a problem on the theory of several complex analysis. The result about the group of CR automorphisms is used to determine the unit component of group of 1-quasiconformal mappings.     

关于Beltrami方程组的问题

使用Hodge分解得到了下列结果 :若f∈W1,n(1-ε)0 (Ω ,Rn) ,n>33为Beltrami方程组 (1 )的广义解 ,并且ε<14× 1 0 4lognabn/2 ,这里a与b来自 (2 ) ,则f=0 ,a .e.Ω .