Observational constraints on the LLTB model

Illustrative example

Valerio Marra and Mikko Pääkkönen
arXiv:1009.4193v3 [astro-ph.CO]
JCAP 1012, 021 (2010)

We directly compare the concordance LCDM model to the inhomogeneous matter-only alternative represented by LTB void models. To achieve a "democratic" confrontation we explore LLTB models with non-vanishing cosmological constant and perform a global likelihood analysis in the parameter space of cosmological constant and void radius. In our analysis we carefully consider SNe, Hubble constant, CMB and BAO measurements, marginalizing over spectral index, age of the universe and background curvature. We find that the LCDM model is not the only possibility compatible with the observations, and that a matter-only void model is a viable alternative to the concordance model only if the BAO constraints are relaxed. Moreover, we will show that the areas of the parameter space which give a good fit to the observations are always disconnected with the result that a small local void does not significantly affect the parameter extraction for LCDM models.

LLTB 1.0 - 18 Nov 2010 - download
The LLTB package has been written using Mathematica 6.0.3 and it is not directly compatible with earlier versions. Instructions are inside the tarball. It is released under the GPL license.

Pre-compiled Mathematica notebooks with animations for exploring a wide range of universe ages and background curvatures are available below. Every observable/combination has its own notebook, about 10 MB. Enjoy :)

SNe   --   H0   --   CMB   --   BAO   --   SNe+H0+CMB  --   SNe+H0+CMBm --   SNe+H0+CMB+BAO--   SNe+H0+CMBm+BAO


PS: the confidence levels might not be always accurate

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