Recently, B. Y. Chen and F. Dillen established general sharp inequalities for multiply warped product submanifolds in arbitrary Riemannian manifolds. As applications, they obtained obstructions to minimal isometric immersions of multiply warped products into Riemannian manifolds. Later, the authors proved similar inequalities for multiply warped products isometrically immersed in Sasakian space...

We show that the pseudohermitian sectional curvature Hθ(σ) of a contact form θ on a strictly pseudoconvex CR manifold M measures the difference between the lengthes of a circle in a plane tangent at a point of M and its projection on M by the exponential map associated to the Tanaka-Webster connection of (M, θ). Any Sasakian manifold (M, θ) whose pseudohermitian sectional curvature Kθ(σ) is a p...

Recently, the author established general inequalities for CR-doubly warped products isometrically immersed in Sasakian space forms. In the present paper, we obtain sharp estimates for the squared norm of the second fundamental form (an extrinsic invariant) in terms of the warping functions (intrinsic invariants) for contact CR-doubly warped products isometrically immersed in Kenmotsu space form...

In the present paper we studied the properties of them−projective curvature tensor in LP-Sasakian, Einstein LP-Sasakian and η−Einstein LPSasakian manifolds.

In this study, we consider bi-f -harmonic Legendre curves in Sasakian space forms. We investigate necessary and sufficient conditions for a curve to be various cases.

We verify the extension to zero section of momentum construction Kaehler-Einstein metrics and Kaehler-Ricci solitons on total space Y positive rational powers canonical line bundle toric Fano manifolds with possibly irregular Sasaki-Einstein metrics. More precisely, we show that extended metric along has an expression which can be Y, restricts associated unit circle as a transversely (Sasakian ...

We study half lightlike submanifold M of an indefinite transSasakian manifold such that its structure vector field is tangent to M . First we study the general theory for such half lightlike submanifolds. Next we prove some characterization theorems for half lightlike submanifolds of an indefinite generalized Sasakian space form.

A transformation of an n-dimensional Riemannian manifold M , which transforms every geodesic circle of M into a geodesic circle, is called a concircular transformation. A concircular transformation is always a conformal transformation. Here geodesic circle means a curve in M whose first curvature is constant and second curvature is identically zero. Thus, the geometry of concircular transformat...