首页 | 本学科首页   官方微博 | 高级检索  
     检索      


About topology of saddle submanifolds
Authors:A Borisenko  V Rovenski
Institution:a Kharkov National University, Faculty of Mechanics and Mathematics, Geometry Department, Svobodi sq. 4, Kharkov, 61077, Ukraine
b Department of Mathematics, Faculty of Science and Science Education, University of Haifa, Mount Carmel, Haifa, 31905, Israel
Abstract:The (k,ε)-saddle (in particular, k-saddle, i.e. ε=0) submanifolds are defined in terms of eigenvalues of the second fundamental form. This class extends the class of submanifolds with extrinsic curvature bounded from above, i.e. ?ε2 (in particular, non-positive) and small codimension. We study s-connectedness and (co)homology properties of compact submanifolds with ‘small’ normal curvature and saddle submanifolds in Riemannian spaces of positive (sectional or qth Ricci) curvature. The main results are that a submanifold or the intersection of two submanifolds is s-connected under some assumption. By the way, theorems by T. Frankel and some recent results by B. Wilking, F. Fang, S. Mendonça and X. Rong are generalized.
Keywords:53B25  53C40
本文献已被 ScienceDirect 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号