مشخصات پژوهش

Abstract. In this talk, we study the C-biharmonicity of a spacelike hypersurface in M5 1(c) defined by x : M4 ! M5 1(c). This condition means that x satisfies the condition C2x = 0 which is an extended version of biharmonicity condition ∆2x = 0, where C is the Cheng-Yau operator and ∆ is the wellknown Laplace operator. We show that if a mentioned hypersurface has at most two distinct principal and constant mean curvature then it is 1-maximal.