Semi-invariant Submanifolds of a Normal Almost Paracontact Manifold

Abstract

In this paper, we introduce the notion of semi-invariant submanifolds of a nor- mal almost para contact manifold. We study their fundamental properties and the particular cases. The necessary and sufficient conditions are given for a submanifold to be invariant or anti-invariant. Also, we give some results for space form and we construct an example. We think that these results will contribute to the differential geometry.