Backreaction in Late-Time Cosmology

@article{Buchert2011BackreactionIL,
  title={Backreaction in Late-Time Cosmology},
  author={Thomas Buchert and Syksy Rasanen},
  journal={Annual Review of Nuclear and Particle Science},
  year={2011},
  volume={62},
  pages={57-79}
}
  • T. Buchert, S. Rasanen
  • Published 22 December 2011
  • Physics
  • Annual Review of Nuclear and Particle Science
We review the effect of the formation of nonlinear structures on the expansion rate, spatial curvature, and light propagation in the universe, focusing on the possibility that this effect could explain cosmological observations without requiring the introduction of dark energy or modified gravity. We concentrate on explaining the relevant physics and highlighting open questions. 

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References

SHOWING 1-10 OF 203 REFERENCES

Dark energy from backreaction

We consider the effect of inhomogeneities on the expansion of the Einstein–de Sitter universe. We find that the back-reaction of linear scalar metric perturbations results in apparent dark energy

Backreaction of linear perturbations and dark energy

A simple discussion on the backreaction of inhomogeneities in cosmology, focusing on the possibility that it could explain the present acceleration and solve the coincidence problem.

Backreaction: directions of progress

Homogeneous and isotropic cosmological models with ordinary matter and gravity predict slower expansion and shorter distances than observed. It is possible that this failure is due the known

BACKREACTION PROBLEM FOR COSMOLOGICAL PERTURBATIONS

We derive the effective energy-momentum tensor for cosmological perturbations and prove its gauge-invariance. The result is applied to study the influence of perturbations on the behaviour of the

Applicability of the linearly perturbed FRW metric and Newtonian cosmology

It has been argued that the effect of cosmological structure formation on the average expansion rate is negligible, because the linear approximation to the metric remains applicable in the regime of

On the Back Reaction Problem for Gravitational Perturbations

We derive the effective energy-momentum tensor for cosmological perturbations and prove its gauge-invariance. The result is applied to study the influence of perturbations on the behaviour of the

Accelerated expansion from structure formation

We discuss the physics of backreaction-driven accelerated expansion. Using the exact equations for the behaviour of averages in dust universes, we explain how large-scale smoothness does not imply

The universe seen at different scales

Constraints on backreaction in dust universes

We study backreaction in dust universes using exact equations which do not rely on perturbation theory, concentrating on theoretical and observational constraints. In particular, we discuss the
...