An optimal gap theorem for scalar curvature of CMC hypersurfaces in a sphere

Author:

Lei Li,Xu Hongwei,Xu Zhiyuan

Abstract

Let M n M^n be a closed hypersurface with constant mean curvature and constant scalar curvature in the unit sphere S n + 1 \mathbb {S}^{n+1} . Denote by S S and H H the squared length of the second fundamental form and the mean curvature of M M , respectively. For a fixed integer k k , where 1 k n 2 1\leq k\leq n-2 , we prove that there exists a positive constant γ ( n ) \gamma (n) depending only on n n , such that if | H | > γ ( n ) |H|>\gamma (n) and α k ( n , H ) S α k + 1 ( n , H ) \alpha _k(n,H)\leq S \leq \alpha _{k+1}(n,H) , then either S = α k ( n , H ) S=\alpha _k(n,H) and M M must be the Clifford torus S n k ( 1 1 + λ k 2 ) × S k ( λ k 1 + λ k 2 ) \mathbb {S}^{n-k}\big (\frac {1}{\sqrt {1+\lambda _k^2}}\big )\times \mathbb {S}^{k}\big (\frac {\lambda _k}{\sqrt {1+\lambda _k^2}}\big ) , or S = α k + 1 ( n , H ) S=\alpha _{k+1}(n,H) and M M is the Clifford torus S n k 1 ( 1 1 + λ k + 1 2 ) × S k + 1 ( λ k + 1 1 + λ k + 1 2 ) \mathbb {S}^{n-k-1}\big (\frac {1}{\sqrt {1+\lambda _{k+1}^2}}\big )\times \mathbb {S}^{k+1}\big (\frac {\lambda _{k+1}}{\sqrt {1+\lambda _{k+1}^2}}\big ) . Here α k ( n , H ) = n + n 3 2 k ( n k ) H 2 n ( n 2 k ) 2 k ( n k ) n 2 H 4 + 4 k ( n k ) H 2 \alpha _k(n,H)=n+\frac {n^3}{2k(n-k)}H^2-\frac {n(n-2k)}{2k(n-k)}\sqrt {n^2H^4+4k(n-k)H^2} and λ k = n | H | + n 2 H 2 + 4 k ( n k ) 2 ( n k ) \lambda _k=\frac {n|H|+\sqrt {n^2H^2+4k(n-k)}}{2(n-k)} .

Funder

National Natural Science Foundation of China

Publisher

American Mathematical Society (AMS)

Subject

Applied Mathematics,General Mathematics

Reference34 articles.

1. A closed hypersurface with constant scalar and mean curvatures in 𝑆⁴ is isoparametric;Chang, Shaoping;Comm. Anal. Geom.,1993

2. On minimal hypersurfaces with constant scalar curvatures in 𝑆⁴;Chang, Shaoping;J. Differential Geom.,1993

3. On closed hypersurfaces of constant scalar curvatures and mean curvatures in 𝑆ⁿ⁺¹;Chang, Shaoping;Pacific J. Math.,1994

4. Totally umbilic hypersurfaces;Cheng, Qing Ming;Hiroshima Math. J.,1990

5. On the Chern conjecture for minimal hypersurface with constant scalar curvatures in the spheres;Cheng, Shiu-Yuen,1997

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