Indefinite Generalized Sasakian Space Form Admitting a Lightlike Hypersurface

In this paper, we study the geometry of indefinite generalized Sasakian space form (M) over bar (f(1), f(2), f(3)) admitting a lightlike hypersurface M subject such that the almost contact structure vector field zeta of (M) over bar (f(1), f(2), f(3)) is tangent to M. We prove a classification theorem of such an indefinite generalized Sasakian space form.