共查询到17条相似文献,搜索用时 515 毫秒
1.
球空间S^n+p(C)中的紧致极小子流形 总被引:4,自引:0,他引:4
设 M~n 是常曲率空间 S~(n+p)(c)的紧致极小子流形,设 K 和 Q 分别是 M~n 上每点各方向截面曲率和 Ricci 曲率的下确界,R 是 M~n 的数量曲率,本文利用 M~n 的内在量 KQ和 R,给出球空间中紧致极小子流形是全测地子流形的六个充分条件。 相似文献
2.
本文给出了四元数射影空间中紧致全实伪脐子流形关于截面曲率和Ricci曲率的Pinching定理,并推广和改进了四元数射影空间中紧致全实极小流形的一些结果. 相似文献
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邓义华 《数学的实践与认识》2009,39(8)
研究了拟常曲率空间中的2-调和子流形与极小子流形.首先得到了拟常曲率空间中具有平行平均曲率的2-调和子流形为极小子流形的一个较好的充分条件,然后得到了2-调和超曲面与极小超曲面在一定条件下是等价的结论. 相似文献
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利用Chern联络D、Cartan张量A以及第二基本形式H.研究了Finsler子流形中的诱导Chern联络与第一、第二曲率R和P,给出了子流形的关于R曲率、P曲率以及flag曲率的Gauss方程。 相似文献
6.
聂昌雄 《数学年刊A辑(中文版)》2015,36(1):59-68
[Nie C X,Wu C X,Regular submanifolds in the conformal space Q_p~n,ChinAnn Math,2012,33B(5):695-714]中研究了共形空间Q_s~n中的正则子流形,并引入了共形空间Q_s~n中的子流形理论.本文作者将分类共形空间Q_s~n中的Blaschke拟全脐子流形,证明伪Riemann空间形式中具有常数量曲率和平行的平均曲率向量场的正则子流形是共形空间中的Blaschke拟全脐子流形;反之,共形空间中的Blaschke拟全脐子流形共形等价于伪Riemann空间形式中具有常数量曲率和平行的平均曲率向量场的正则子流形.这一结论可看作是共形空间Q_s~n中共形迷向子流形分类定理的推广. 相似文献
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设Mn是复射影空间CPn+p/2中具有平坦法丛的一般极小子流形.该文研究了这种子流形的曲率性质与几何性质之间的关系.运用活动标架法,得到关于Ricci曲率和第二基本形式模长的刚性定理,完善了已有文献的相关结果.此外,该文还得到具有平坦法丛的一般子流形一个重要性质. 相似文献
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本文改进了S.T.Yau(文[1])中关于单位球面中具有平行平均曲率向量场的子流形的一个结果。然而从截面曲率这一角度出发,给出了空间形式R^n+p(c)(n>1,p>1)中具有平行平均曲率向量场的可定向闭子流形M^n的有关结果和积分不等式。 相似文献
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Barbara Opozda 《Monatshefte für Mathematik》2009,156(4):357-370
One of the basic facts known in the theory of minimal Lagrangian surfaces is that a minimal Lagrangian surface of constant
curvature in C
2 must be totally geodesic. In affine geometry the constancy of curvature corresponds to the local symmetry of a connection.
In Opozda (Geom. Dedic. 121:155–166, 2006), we proposed an affine version of the theory of minimal Lagrangian submanifolds.
In this paper we give a local classification of locally symmetric minimal affine Lagrangian surfaces in C
2. Only very few of surfaces obtained in the classification theorems are Lagrangian in the sense of metric (pseudo-Riemannian)
geometry.
The research supported by the KBN grant 1 PO3A 034 26. 相似文献
13.
In this paper, we obtain some sharp inequalities between the Ricci cur- vature and the squared mean curvature for bi-slant and semi-slant submanifolds in Kenmotsu space forms. Estimates of the scalar curvature and the k-Ricci curvature, in terms of the squared mean curvature, are also proved respectively. 相似文献
14.
单位球面的三维紧致极小子流形 总被引:3,自引:0,他引:3
本文得到高维球面上三维紧致极小子流形的若干刚性定理.在一个整体拚挤条件下,数量曲率的拚挤常数被改进了,也对李奇曲率的拚挤问题进行了讨论. 相似文献
15.
Miroslava ANTIC Mirjana DJORIC Luc VRANCKEN 《数学学报(英文版)》2006,22(5):1557-1564
In this paper, we study Lagrangian submanifolds of the nearly Kaehler 6-sphere. We derive a pinching result for the Ricci curvature of such submanifolds thus providing a characterisation of the totally geodesic submanifold. Our pinching result improves a previous result obtained by H. Li. 相似文献
16.
Given a closed connected manifold smoothly immersed in a complete noncompact Riemannian manifold with nonnegative sectional curvature, we estimate the intrinsic diameter of the submanifold in terms of its mean curvature field integral. On the other hand, for a compact convex surface with boundary smoothly immersed in a complete noncompact Riemannian manifold with nonnegative sectional curvature, we can estimate its intrinsic diameter in terms of its mean curvature field integral and the length of its boundary. These results are supplements of previous work of Topping, Wu-Zheng and Paeng. 相似文献
17.
A. A. Borisenko 《Mathematical Notes》1996,60(1):3-7
In this paper we consider compact multidimensional surfaces of nonpositive external curvature in a Riemannian space. If the
curvature of the underlying space is ≥ 1 and the curvature of the surface is ≤ 1, then in small codimension the surface is
a totally geodesic submanifold that is locally isometric to the sphere. Under stricter restrictions on the curvature of the
underlying space, the submanifold is globally isometric to the unit sphere.
Translated fromMatematicheskie Zametki, Vol. 60, No. 1, pp. 3–10, July, 1996. 相似文献