Towards conformally flat, non-Kasner vacuum solution in infinite derivative gravity

Abstract

In this paper, we will show that the equations of motion of the quadratic in curvature, ghost free, infinite derivative theory of gravity will not permit an anisotropic collapse of a homogeneous Universe such as Kasner-type vacuum solution. However, such a solution is shown to be admissible in the local quadratic curvature gravity. Therefore pointing towards the crucial role played by the non-local infinite derivatives. We will show that it is possible to obtain conformally flat and singularity-free spacetime metrics.