Let M^n be an n(n≥4)-dimensional compact oriented submanifold in the non- negative space forms N^n+p(c) with S ≤ S(c,H). Then M^n is either homeomorphic to a standard n-dimensional sphere S^n or isometric to ...Let M^n be an n(n≥4)-dimensional compact oriented submanifold in the non- negative space forms N^n+p(c) with S ≤ S(c,H). Then M^n is either homeomorphic to a standard n-dimensional sphere S^n or isometric to a Clifford torus. We also prove that a compact oriented submanifold in any N^n+p (c) is diffeomorphic to a sphere if S≤(n^2H^2)/(n-1)+2c.展开更多
基金Supported by the National Natural Science Foundation of China(11071206)Supported by the PAPD of Jiangsu Higher Education Institutions
文摘Let M^n be an n(n≥4)-dimensional compact oriented submanifold in the non- negative space forms N^n+p(c) with S ≤ S(c,H). Then M^n is either homeomorphic to a standard n-dimensional sphere S^n or isometric to a Clifford torus. We also prove that a compact oriented submanifold in any N^n+p (c) is diffeomorphic to a sphere if S≤(n^2H^2)/(n-1)+2c.