Totally umbilical lightlike submanifolds

[摘要] References(12)This paper provides new results on a class of totally umbilical lightlike submanifolds in semi-Riemannian manifolds of constant curvature. We prove that the induced Ricci tensor of any such submanifold is symmetric if and only if its screen distribution is integrable.

[学科分类] 数学（综合）

[关键词] Degenerate metric;totally umbilical submanifolds