文摘
We use Bochner’s formula jointly with the generalized maximum principle of Omori-Yau and an extension of Liouville’s theorem due to Yau in order to show that a complete spacelike hypersurface \({\Sigma^{n}}\) immersed with constant mean curvature in a Lorentzian product space \({\overline{M}^{n+1}=-{\mathbb{R}}{\times}M^{n}}\), whose fiber M n has nonnegative sectional curvature, must be a slice, provided that \({\Sigma^{n}}\) is bounded away from the future (or past) infinity of \({\overline{M}^{n+1}}\) and that its normal hyperbolic angle is bounded. We also study the rigidity of entire vertical graphs with constant mean curvature in such an ambient space.