指标为2的半四维欧氏空间中三维Lorentzian子流形的Anti de Sitter高斯映射的奇点

Singularities of Anti de Sitter Gauss Map of Lorentzian 3-Submanifolds in Semi-Euclidean 4-space with index 2

作为R2^4空间中子流形研究的补充工作，试图利用Lagrange奇点理论对R2^4空间中三维Lorentzian子流形的微分几何性质及奇异性进行研究．

We try to study some geometrical and singular properties of Lorentzian 3- submanifolds in semi-Euclidean 4-space with index 2 by the Lagrange singularity theory.