关于局部对称伪黎曼流形中的2-调和类空子流形

ON 2-HARMONIC SPACE-LIKE SUBMANIFOLDS OF A LOCALLY SYMMETRIC PSEUDO-RIMANNIAN MANIFOLD

研究局部对称伪黎曼流形中的2-调和类空子流形,得到了这类子流形成为极大的Pinching现象及推广的J．Simons型积分不等式．

Let Np^n＋p be a locally symmetric pseudo-Riemanian manifold, whose sectional curvatrue KN satisties 0 〈 δ≤ KN ≤1. Let M^n be a 2-harmonic space-like submanifold in Np^n＋p. In this paper, we obtain a pinching theorem for the square of the length of the second fundamental form and an integral formula.