Special Half Lightlike Submanifolds of an Indefinite Cosymplectic Manifold

We study the geometry of half lightlike submanifolds M of an indefinite cosymplectic manifold (M) over bar. First, we construct two types of half lightlike submanifolds according to the form of the structure vector field of (M) over bar, named by tangential and ascreen half lightlike submanifolds. Next, we characterize the lightlike geometries of such two types of half lightlike submanifolds.