Hypersurfaces with constant -th mean curvature in a Lorentzian space form
In this paper, we study -dimensional complete connected and oriented space-like hypersurfaces in an (n+1)-dimensional Lorentzian space form with non-zero constant -th mean curvature and two distinct principal curvatures and . We give some characterizations of Riemannian product and show that the Riemannian product is the only complete connected and oriented space-like hypersurface in with constant -th mean curvature and two distinct principal curvatures, if the multiplicities of...