LIGHTLIKE PARALLEL VECTOR FIELDS AND EINSTEINS EQUATIONS OF GRAVITY: A PARTIAL SOLUTION

Abstract

The purpose of this paper was to find out the lightlike parallel vector field and Einsteins equation of gravity, specifically a partial solution. The pseudo “Riemannian manifold and gravitational field through Einsteins equation have been used , the curvature tensor in 4 dimensional space and the  Christoffel symbols in 3- dimensional are equal to Christoffel symbols in 4- dimensional space  by using contraction properties of  the tensors and as the results  the existence of lightlike parallel vector field implies that the space time is flat, this leads us to non existence of  the lightlike parallel vector field in a non trivial gravitational field.