No abstract

The object of the present paper is to characterize generalized Sasakian-space-forms satisfying certain curvature conditions on conharmonic curvature tensor. In this paper we study conharmonically semisymmetric, conharmonically flat, -conharmonically flat, and conharmonically recurrent generalized Sasakian-space-forms. Also generalized Sasakian-space-forms satisfying and have been studied.

Abstract. The object of the present paper is to study a semi-symmetric metric connection in an (ε)-Kenmotsu manifold. In this paper, we study a semi-symmetric metric connection in an (ε)-Kenmotsu manifold whose projective curvature tensor satisfies certain curvature conditions.

Abstract:The object of the present paper is to study a semi-symmetric non-metric connection in an indefinite para Sasakian manifold. In this paper, we obtain the relation between the semi-symmetric non-metric connection and Levi-Civita connection in an indefinite para Sasakian manifold. Also, the Nijenhuis tensor, curvature tensor and projective curvature tensor of semi-symmetric non-metric connection in an indefinite para Sasakian manifold have been studied.

The object of the present paper is to study an invariant submanifold of hyperbolic Sasakian maifolds. In this paper, we consider semiparallel and 2-semiparallel invariant submanifolds of hyperbolic Sasakian manifold and it is shown that these submanifolds are totally geodesic. It is also proved that on an invariant submanifold of hyperbolic Sasakian manifolds the conditions $I(X, Y).\alpha = 0$, $I(X, Y).\tilde{\nabla}\alpha = 0$, $C(X, Y).\alpha = 0$, $C(X, Y).\tilde{nabla}\alpha = 0$ holds if and only if it is totally geodesic.