Cosmic Jerk and Snap in Penrose's CCC model
  We obtain a constraint on cosmological scalars for the FRW metric with a pure radiation fluid source and positive cosmological constant. We demonstrate that this constraint is conformally invariant in the context of Penrose's Conformal Cyclic Cosmology proposal, where the metrics of the late stages of the previous aeon and the early stages of the present aeon are described by FRW cosmologies. 
Maciej Dunajski
gr-qc astro-ph.CO hep-th