Swiss-cheese models and the Dyer-Roeder approximation

@article{Fleury2014SwisscheeseMA,
  title={Swiss-cheese models and the Dyer-Roeder approximation},
  author={Pierre Fleury},
  journal={Journal of Cosmology and Astroparticle Physics},
  year={2014},
  volume={2014},
  pages={054 - 054}
}
  • P. Fleury
  • Published 13 February 2014
  • Physics
  • Journal of Cosmology and Astroparticle Physics
In view of interpreting the cosmological observations precisely, especially when they involve narrow light beams, it is crucial to understand how light propagates in our statistically homogeneous, clumpy, Universe. Among the various approaches to tackle this issue, Swiss-cheese models propose an inhomogeneous spacetime geometry which is an exact solution of Einstein's equation, while the Dyer-Roeder approximation deals with inhomogeneity in an effective way. In this article, we demonstrate that… 

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

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

The theory of stochastic cosmological lensing

On the scale of the light beams subtended by small sources, e.g. supernovae, matter cannot be accurately described as a fluid, which questions the applicability of standard cosmic lensing to those

On the relationship between mean observations, spatial averages and the Dyer-Roeder approximation in Einstein-Straus models

  • S. Koksbang
  • Physics
    Journal of Cosmology and Astroparticle Physics
  • 2020
The redshift and redshift-distance relation in different Einstein-Straus models are considered. Specifically, the mean of these observables along 1000 light rays in different specific models are

Light path averages in spacetimes with nonvanishing average spatial curvature

Effects of inhomogeneities on observations have been vastly studied using both perturbative methods, N-body simulations and Swiss cheese solutions to the Einstein equations. In nearly all cases, such

Precision cosmology with the large-scale structure of the universe

This thesis provides innovative results of different types. What they have in common is the quest for precision in the description of the physical phenomena at work in the universe. First, a toy

Light Propagation and Observations in Inhomogeneous Cosmological Models

The science of cosmology relies heavily on interpreting observations in the context of a theoretical model. If the model does not capture all of the relevant physical effects, the interpretation of

Light propagation through black-hole lattices

The apparent properties of distant objects encode information about the way the light they emit propagates to an observer, and therefore about the curvature of the underlying spacetime. Measuring the

Cosmological backreaction in the presence of radiation and a cosmological constant

We construct high-precision models of the Universe that contain radiation, a cosmological constant, and periodically distributed inhomogeneous matter. The density contrasts in these models are

Ray tracing and Hubble diagrams in post-Newtonian cosmology

On small scales the observable Universe is highly inhomogeneous, with galaxies and clusters forming a complex web of voids and filaments. The optical properties of such configurations can be quite

CMB seen through random Swiss Cheese

We consider a Swiss Cheese model with a random arrangement of Lemaȋtre-Tolman-Bondi holes in ΛCDM cheese. We study two kinds of holes with radius rb=50 h−1 Mpc, with either an underdense or an

References

SHOWING 1-10 OF 95 REFERENCES

Cosmological observables in a Swiss-cheese universe

Photon geodesics are calculated in a Swiss-cheese model, where the cheese is made of the usual Friedmann-Robertson-Walker (FRW) solution and the holes are constructed from a Lemaitre-Tolman-Bondi

‘Swiss-cheese’ inhomogeneous cosmology and the dark energy problem

We study an exact Swiss-cheese model of the universe, where inhomogeneous LTB patches are embedded in a flat FLRW background, in order to see how observations of distant sources are affected. We

Swiss cheese and a cheesy CMB

It has been argued that the Swiss-Cheese cosmology can mimic Dark Energy, when it comes to the observed luminosity distance-redshift relation. Besides the fact that this effect tends to disappear on

Interpretation of the Hubble diagram in a nonhomogeneous universe

In the standard cosmological framework, the Hubble diagram is interpreted by assuming that the light emitted by standard candles propagates in a spatially homogeneous and isotropic spacetime.

Ricci focusing, shearing, and the expansion rate in an almost homogeneous Universe

The Universe is inhomogeneous, and yet it seems to be incredibly well-characterised by a homogeneous relativistic model. One of the current challenges is to accurately characterise the properties of

Weak lensing and the Dyer–Roeder approximation

The distance-redshift relation plays an important role in cosmology. In the standard approach to cosmology, it is assumed that this relation is the same as in a homogeneous universe. As the real

Average expansion rate and light propagation in a cosmological Tardis spacetime

We construct the first exact statistically homogeneous and isotropic cosmological solution in which inhomogeneity has a significant effect on the expansion rate. The universe is modelled as a Swiss

Light propagation and the distance-redshift relation in a realistic inhomogeneous universe.

The propagation of light rays in a clumpy universe constructed by cosmological version of the post-Newtonian approximation was investigated. It is shown that linear approximation to the propagation

Lightcone Averaging and Precision Cosmology

The first objective of this thesis is to fill the lack in cosmology of a description on the past light cone: the null hypersurface on which observed signals propagate. Its second goal is to evaluate

Can all cosmological observations be accurately interpreted with a unique geometry?

This Letter shows that using an inhomogeneous "Swiss-cheese" model to interpret the Hubble diagram allows us to reconcile the inferred value of Ω(m0) with the Planck results.
...