Open universes and avoidance of the cosmological singularity
  In the present paper we give conclusive arguments pointing at physical equivalence among conformally related metrics. Based on the argument that any consistent effective theory of spacetime must be invariant under the one-parameter group of transformations of the units of length, time and reciprocal mass, it is shown, also, that canonical general relativity is not such a consistent theory. Conformal general relativity provides a consistent formulation of the laws of gravity instead. We further extend the results of papers gr-qc/9908075 and gr-qc/9905071 to open universes by studying the Raychaudhuri equation. 
Israel Quiros, Rolando Cardenas and Rolando Bonal (Departamento de   Fisica. Universidad Central de Las Villas. Santa Clara....