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} }
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…
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References
SHOWING 1-10 OF 95 REFERENCES
Cosmological observables in a Swiss-cheese universe
- Physics
- 2007
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
- Physics
- 2008
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
- Physics
- 2009
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
- Physics
- 2013
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
- Physics
- 2012
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
- Physics
- 2010
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
- Physics
- 2013
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.
- PhysicsPhysical review. D, Particles and fields
- 1989
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
- Physics
- 2013
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?
- PhysicsPhysical review letters
- 2013
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.