“Whimpers” in Self-Similar Cosmologies

Abstract

We examine how self-similarity influences the occurrence & nature of singularities in self-similar cosmologies. There exists a density divergence due to a conformal factor in any Self-similar model. If we discuss the singularity problem in an “unphysical” homogeneous model which is conformally related to the self-similar model, it is easy to show-that in a Class D model with , singularity behaviour is similar to that in homogeneous cosmologies. The Boyer-Ehlers analysis of Killing geodesicsic has been generalized to the self-similar case. Some new Penrose diagrams are given.