~n上的非初等变换群及其极限集

该文对高维非初等Mobius变换群进行了研究,得到了一些重要性质,给出了几个关于离散准则和代数收敛性的定理.     

关于小伸缩商拟共形群的几个定理

本文研究了单位球Bn上小伸缩商拟共形群的离散性质，给出了一个收敛定理，并且证明了在一定限制条件下任意一个非初等非离散小伸缩商拟共形群含有一个二元生成的非初等非离散子群。     

单位球B~n上小伸缩商拟共形群

本文研究了单位球Bn上小伸缩商拟共形群的离散性质,给出了几个离散判别准则和收敛定理.     

单位球Bn上小伸缩商拟共形群

本文研究了单位球Bn上小伸缩商拟共形群的离散性质,给出了几个离散判别准则和收敛定理.     

Pinched流形上等距群的几个性质

本文建立了Ｐｉｎｃｈｅｄ流形Ｘ上等距群Ｍ（Ｘ）中的Ｊｏｒｇｅｎｓｅｎ型不等式;证得了Ｍ（Ｘ）中非初等群的一个几何特征,得到了Ｍ（Ｘ）中子群的两个离散准则。     

连续树映射的ω极限集与非游荡集

本文研究树上连续自映射f的ω极限集∧,非游荡集Ω的若干拓扑结构,主要证明了不在周期点集闭包中的ω极限点都有无限轨迹;Ω-     

连续树映射的ω极限集与非游荡集

本文研究树上连续自映射ｆ的ω极限集Λ,非游荡集Ω的若干拓扑结构,主要证明了：不在周期点集闭包中的ω极限点都有无限轨迹;Ω－Ｐ,Ω－Γ为可数集,Λ－Γ,Ｐ－Γ或为空集或可数无限,其中Γ为ｆ的γ极限集．     

关于Clifford矩阵群的代数收敛性

在条件B之下,本文得到了Clifford矩阵群,即n维Mbius群的非初等子群列{Gm}的几个代数收敛定理,并且证明了一致有界挠群列满足离散群所必须满足的条件B.     

关于Clifford矩阵群的代数收敛性

在条件B之下,本文得到了Clifford矩阵群,即n维M■bius群的非初等子群列｛Gm｝的几个代数收敛定理,并且证明了一致有界挠群列满足离散群所必须满足的条件。     

Hadamard流形上等距子群的离散准则

本文对Hadamard流形上的等距群Isom(X)进行了研究,得到了几个关于离 散准则和代数收敛性的定理.     

On Limit Sets and Discreteness Criteria for Nonelementary Subgroups of M（R^n）

In this paper, we will study the nonelementary groups of MSbius transformations in R^n and some properties are obtained. Also in this paper we will prove several theorems about discreteness criteria and group convergence of nonelementary groups of M（R^n）.     

Fuchsian Groups, Quasiconformal Groups, and Conical Limit Sets

We construct examples showing that the normalized Lebesgue measure of the conical limit set of a uniformly quasiconformal group acting discontinuously on the disc may take any value between zero and one. This is in contrast to the cases of Fuchsian groups acting on the disc, conformal groups acting discontinuously on the ball in dimension three or higher, uniformly quasiconformal groups acting discontinuously on the ball in dimension three or higher, and discrete groups of biholomorphic mappings acting on the ball in several complex dimensions. In these cases the normalized Lebesgue measure is either zero or one.

     

Hall’s Theorem for Limit Groups

A celebrated theorem of Marshall Hall Jr. implies that finitely generated free groups are subgroup separable and that all of their finitely generated subgroups are retracts of finite-index subgroups. We use topological techniques inspired by the work of Stallings to prove that all limit groups share these two properties. This answers a question of Sela. Received: May 2006 Revision: May 2007 Accepted: May 2007     

有关Clifford矩阵群的几个离散性判别准则

研究了Clifford矩阵变换群的离散性质,给出了几个判别离散群的不等式和定理.     

Rn中区域上的加权Hardy定理

Ω С Rⁿ是一个区域时,该文给出了区域Ω上加权Hardy空间的定义,并得到该空间的原子分解,所得的定理在椭圆边界值问题的研究中有潜在的应用.     

On Relative Difference Sets in Dihedral Groups

In this paper, we study extensions of trivial difference sets in dihedral groups. Such relative difference sets have parameters of the form (uλ,u,uλ, λ) or (uλ+2,u, uλ+1, λ) and are called semiregular or affine type, respectively. We show that there exists no nontrivial relative difference set of affine type in any dihedral group. We also show a connection between semiregular relative difference sets in dihedral groups and Menon–Hadamard difference sets. In the last section of the paper, we consider (m, u, k, λ) difference sets of general type in a dihedral group relative to a non-normal subgroup. In particular, we show that if a dihedral group contains such a difference set, then m is neither a prime power nor product of two distinct primes.     

On the Limit Set of Discrete Subgroups of PU(2,1)

Let G be a discrete subgroup of PU(2,1); G acts on preserving the unit ball , equipped with the Bergman metric. Let be the limit set of G in the sense of Chen–Greenberg, and let be the limit set of the G-action on in the sense of Kulkarni. We prove that L(G) = Λ(G) ∩ S ³ and Λ(G) is the union of all complex projective lines in which are tangent to S ³ at a point in L(G).     

紧度量空间上轨道的分类和极限集有向同伦不变性

本文利用正半轨道的ω极限集对紧度量空间的正半轨道进行分类,并讨论不动点和周期点的存在性.最后,引入轨道的正半同伦和负半同伦的概念,证明ω极限集和ω极限集在正半同伦和负半同伦的条件下是不变的,从而导出不动点和周期点在正半同伦和负半同伦的条件下保持不变.