Focusing of geodesic congruences in an accelerated expanding Universe

@article{Albareti2012FocusingOG,
  title={Focusing of geodesic congruences in an accelerated expanding Universe},
  author={Franco D. Albareti and Jos{\'e} Alberto Ruiz Cembranos and Alvaro de la Cruz-Dombriz},
  journal={Journal of Cosmology and Astroparticle Physics},
  year={2012},
  volume={2012},
  pages={020-020}
}
We study the accelerated expansion of the Universe through its consequences on a congruence of geodesics. We make use of the Raychaudhuri equation which describes the evolution of the expansion rate for a congruence of timelike or null geodesics. In particular, we focus on the space-time geometry contribution to this equation. By straightforward calculation from the metric of a Robertson-Walker cosmological model, it follows that in an accelerated expanding Universe the space-time contribution… Expand

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