Special Half Lightlike Submanifolds of an Indefinite Cosymplectic Manifold

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