Lightlike Submanifolds with Planar Normal Section in Semi Riemannian Product Manifolds

Abstract

In the present paper we give conditions for screen semi invariant lightlike submanifolds of a semi- Riemannian product manifold to have degenerate planar normal sections. Also we give sufficient and efficient conditions for screen invariant and screen anti invariant lightlike submanifold of a semi-Riemanniann product manifold to have non-degenerate planar normal sections.