A New Pinching Theorem for Closed Hypersurfaces with Constant Mean Curvature in $S^{n+1}$

We investigate the generalized Chern conjecture, and prove that if $M$ is a closed hypersurface in $S^{n+1}$ with constant scalar curvature and constant mean curvature, then there exists an explicit positive constant $C(n)$ depending only on $n$ such that if $|H| \lt C(n)$ and $S \gt \beta (n,H)$, then $S \gt \beta (n,H) + \frac{3n}{7}$, where $\beta(n,H) = n + \frac{n^3 H^2}{2(n−1)} + \frac{n(n−2)}{2(n−1)} \sqrt{n^2 H^4 + 4(n − 1)H^2}$.

Keywords

Closed hypersurface, pinching phenomenon, mean curvature, scalar curvature, second fundamental form

2010 Mathematics Subject Classification

53C40, 53C42

Full Text (PDF format)

Published 17 April 2012