球几何三维流形到透镜空间的映射度

本文讨论球几何三维流形M=S~3/G,即S~3在一群G自由作用下的轨道空间.所谓球几何是指S~3上被赋予的标准的度量,其等距变换群是SO(4),而上述G就是SO(4)的离散子群.主要结果是利用Z在ZG模上的投射预解以及群G的上同调和流形K(G,1)的上同调的关系,计算出流形M的系数为Z_m(m不必为素数)的上同调环,以及Bockstein同态H~n(M,Z_m)→H~(n+1)(M,Z_m).利用上述结果进而计算出任一球几何三维流形到三维透镜空间的映射的映射度,最后可以判断一类映射是否具有值为1的映射度.     

Hom-李-Yamaguti代数上的相对罗巴算子

本文引入Hom-李-Yamaguti代数上相对罗巴算子的概念,并利用Nijenhuis算子和图给出相对罗巴算子的等价刻画.随后,引入Hom-李-Yamaguti代数上相对罗巴算子的上同调理论.最后,利用上同调方法探讨相对罗巴算子的形变.     

On General Volume-Preserving Mechanical Systems via Cohomology

We present the general form of equations that generate a volume-preserving flow on a symplectic manifold (M,ω) via the highest Euler-Lagrange cohomology.It is shown that for every volume-preserving flow there are some 2-forms that play a similar role to the Hamiltonian in the Hamilton mechanics and the ordinary canonical equations with Hamiltonian H are included as a special case with a 2-form Hω/(n-1).     

Slowly Increasing Cohomology for Discrete Metric Spaces with Polynomial Growth

The authors introduce a kind of slowly increasing cohomology HS*(X) for a discrete metric space X with polynomial growth,and construct a character map from the slowly increasing cohomology HS*(X) into HC*cont(S(X)),the continuous cyclic cohomology of the smooth subalgebra S(X) of the uniform Roe algebra B*(X).As an application,it is shown that the fundamental cocycle,associated with a uniformly contractible complete Riemannian manifold M with polynomial volume growth and polynomial contractibility radius growth,is slowly increasing.     

关于R~n中Mbius变换群的代数有限性

本文推广了Ｅｉｃｈｌｅｒ在Ｋｌｅｉｎ群的研究中所采用的上同调方法，对于Ｒｎ中的Ｍｂｉｕｓ变换群引进更为一般的线性上同调空间的概念．在此基础上，将作者早期的工作加以推广，研究Ｒｎ中Ｍｂｉｕｓ变换群的代数有限性，并作为特例给出高维Ｋｌｅｉｎ群有限性的一种代数判据．     

On Some Problems Studied by R. V. Kadison

Several problems studied by professor R. V. Kadison are shown to be closely related. The problems were originally formulated in the contexts of homomorphisms of C^*-algebras, cohomology of von Neumann algebras and perturbations of C^*-algebras. Recent research by G. Pisier has demonstrated that all of the problems considered are related to the question of whether all C^*-algebras have finite length.     

Cohomologies of Leibniz Algebras with Higher Derivations北大核心CSCD

本文研究具有高阶导子的莱布尼兹代数.我们称之为LeibHDer对.首先给出LeibHDer对的表示并构造半直积.最后,定义LeibHDer对的上同调并研究其中心扩张和形变理论.     

几何分析中的基本概念与原理

本文是根据作者在中国科学院“中德几何分析伙伴小组”成立仪式上的演讲整理而成，主要目的在于通过回顾几何分析中的基本概念及基本定理，了解现阶段的研究情况和将来的研究线路，主要描述黎曼几何与量子场论中的思想，特别特别是极化物理量与几何量产生的变分问题。     

On Standard Ideals

In the paper,we study a class of standard ideals which are more general than the m-primary standared ideals discussed in[2].We will prove an important equality concerning I-weak sequences;thus a generalization of the equality of [2] is established.