Understanding the Dyer-Roeder approximation as a consequence of local cancellations of projected shear and expansion rate fluctuations

@article{Koksbang2021UnderstandingTD,
  title={Understanding the Dyer-Roeder approximation as a consequence of local cancellations of projected shear and expansion rate fluctuations},
  author={Sofie Marie Koksbang},
  journal={Physical Review D},
  year={2021}
}
It is shown with several concrete examples that the Dyer-Roeder approximation is valid in spacetimes which fulfill the condition that fluctuations in the expansion rate along a light ray locally cancels with the shear contribution to the redshift. This is the case for standard cosmological scenarios including perturbed FLRW spacetimes, N-body simulations and Swiss-cheese models. With another concrete example it is then illustrated that it is possible to construct statistically homogeneous and… Expand

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