On Isometric Immersions of Null Manifolds into Semi-Riemannian Space Forms of Arbitrary Index

A null manifold is a differentiable manifold M endowed with a degenerate metric tensor g. In this work we provide sufficient conditions for a null manifold to be isometrically immersed as a hypersurface into a simple connected semi-Riemannian manifold of constant sectional curvature c and index q