It is well-known that there is a unique vertex on rotating parabolic surface in three-dimensional Euclidiean space,the paper generalizes the concept of vertex to a complete noncompact Riemannian manifold with nonnegative curvature.
将三维欧式空间旋转抛物面顶点的定义推广到一般的非负曲率完备非紧黎曼流形上,利用Perelman G证明Chee-ger-Gromoll核心猜想的几何方法,讨论了具非负曲率的完备非紧黎曼流形M上的核心S的结构,证明了如果由核心出发的法测地线均为射线,则或者S退化为一点,或者M=Rk×N,其中N是紧致的具非负曲率的黎曼流形。
The paper gathers some results in Riemannian manifolds,including in complete geodesics without conjugate points,the geometric struture of a manifold with nonnegative curvature,the topology of a manifold with nonnegative Ricci curvature and some properties of Busemann function etc.
总结了完备黎曼流形上完备的无共轭点测地线所隐含的几何性质、完备非紧具非负曲率黎曼流形的几何结构、完备非紧具非负R icc i曲率黎曼流形的几何拓扑性质以及完备非紧黎曼流形上的Buse-m ann函数所隐含的几何拓扑性质,并提出了一些未解决的问题。
The paper discusses the structure of the soul in a complete noncompact Riemannian manifold M with nonnegative curvature,and proves that if the soul of the manifold is unique,then the soul actually degenerates to a pole.
讨论了具非负曲率的完备非紧黎曼流形上的核心的结构,证明了如果核心是惟一的,那么核心将退化为极点。
Based on the idea of integrable system,taking advantage of matrix model for 3-dimensional Minkowski space L 3,the integrability and curved suface deformation of negative curvity in L 3 were studied.
利用可积系统的思想 ,借助三维Minkowski空间L3的矩阵模型 ,我们研究了L3中常负曲率的类空曲面的形变及其可积性。