Certain types of GRW-spacetimes

http://dergiler.ankara.edu.tr/dergiler/29/1390/15780.pdf

Contact Riemannian manifolds satisfying C(^)S=0 AND 4e(k, n)-nullity distribution

: In this paper, we deﬁne the Lorentzian approximations of a 3-dimensional Lorentzian α Sasakian manifold. Moreover, we deﬁne the notions of the intrinsic curvature for regular curves, the intrinsic geodesic curvature of regular curves on Lorentzian surfaces and spacelike surfaces and the intrinsic Gaussian curvature of Lorentzian surfaces and spacelike surfaces away from characteristic points. Furthermore, we derive the expressions of those curvatures and prove Gauss-Bonnet theorems for the Lorentzian surfaces and spacelike surfaces in the Lorentzian α -Sasakian manifold.

Lorentzian approximations for a Lorentzian α -Sasakian manifold and Gauss-Bonnet theorems

Recently the present author introduced the notion of generalized quasi-conformal curvature tensor which bridges Conformal curvature tensor, Concircular curvature tensor, Projective curvature tensor and Conharmonic curvature tensor. This article attempts to charectrize Sasakian manifolds with

/pdf/semi-symmetry-type-sasakian-manifolds-1qbroh0nj2.pdf

Subir Kumar Dey

Papers

Semi-symmetry type Sasakian manifolds