排序方式: 共有93条查询结果,搜索用时 93 毫秒
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In this paper, we study the properties of the zero set of a homotopy H: I~m×[0, 1]→ and its piecewise linear approximation φ_((?)4): I~m×[0, 1]→R~m, These properties are very important for the homotopy simplex pivot algorithm. However, we prove that for almost every polynomial mapping the zero set of linear homotopy H(z, t) =tp(z)+(1-t)Q(z) consists of q=multiply form j=1 to n(q_j) disjoint differential curves, and the zero set of its piecewise linear approximation φ_(δ4), consists of some broken lines. Where δ_4→0, these broken lines tend to differential curves in the zero srt of H. 相似文献
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In this paper,we study the relation between the excess of open manifolds and their topology by using the methods of comparison geometry.We prove that a complete open Riemmannian manifold with Ricci curvature negatively lower bounded is of finite topological type provided that the conjugate radius is bounded from below by a positive constant and its Excess is bounded by some function of its conjugate radius,which improves some results in [4]. 相似文献
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Let f : M^n→S^n 1真包含于R^n 2 be an n-dimensional complete oriented Riemannian manifold minimally immersed in an (n 1)-dimensional unit sphere S^n 1. Denote by S^n 1 the upper closed hemisphere. If f(M^n)包含于S ^n 1, then under some curvature conditions the authors can get that the isometric immersion is a totally embedding. They also generalize a theorem of Li Hai Zhong on hypersurface of space form with costant scalar curvature. 相似文献
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给出了k维环面上坐标自映射下拓扑熵的一个下界,最后,还指出了k维环面上渐近Reidemeister数严格大于渐近Nielsen数的情形,并说明了文(3)(或文(4)中引理1为该文的一个特例。 相似文献
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m个d-空间之间复合映射的不动点 总被引:3,自引:0,他引:3
给出了m个d-空间之间复合映射在压缩和扩张条件下的几个不动点定理。 相似文献
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在[2]中,R.Bott 和J.Milnor 证明了球面S~n 是可平行流形的充要条件为n=1,3或7.在[1]中,J.F.Adams 证明了上述结果和S~n 是H—空间的充要条件为n=0,1,3或7.因为Lie 群(我们指的是解析Lie 群)必须是可平行流形和H—空间,因此人们自然要问对于n=0,1,3或7,S~n 是Lie 群吗?本文证明了S~7不是Lie 群,甚至也不是拓扑群.于是,S~n 是Lie 群(或拓扑群)的充要条件为n=0,1,3. 相似文献