Abstract
In this paper we consider semi-invariant warped product submanifolds of the type M = N-T x psi N-perpendicular to of a generalized Sasakian space form (M) over bar (f(1), f(2), f(3)) admitting nearly cosymplectic structure and obtained a characterizing inequality (parallel to sigma(mu)(D,D-perpendicular to parallel to(2) >= integral 2.alpha.beta+2 parallel to P-D perpendicular to D parallel to(2) +2 parallel to Q(D) perpendicular to D parallel to(2)) for existence of warped product submanifolds. Moreover, some special cases are also discussed. The results in the present paper generalize the existing results available in the literature.