Article ID Journal Published Year Pages File Type
1770856 Astroparticle Physics 2012 11 Pages PDF
Abstract

In this article we investigate the properties of the FLRW flat cosmological models in which the cosmic expansion of the Universe is affected by a dilaton dark energy (Liouville scenario). In particular, we perform a detailed study of these models in the light of the latest cosmological data, which serves to illustrate the phenomenological viability of the new dark energy paradigm as a serious alternative to the traditional scalar field approaches. By performing a joint likelihood analysis of the recent supernovae type Ia data (SNIa), the differential ages of passively evolving galaxies, and the baryonic acoustic oscillations (BAOs) traced by the Sloan Digital Sky Survey (SDSS), we put tight constraints on the main cosmological parameters. Furthermore, we study the linear matter fluctuation field of the above Liouville cosmological models. In this framework, we compare the observed growth rate of clustering measured from the optical galaxies with those predicted by the current Liouville models. Performing various statistical tests we show that the Liouville cosmological model provides growth rates that match well with the observed growth rate. To further test the viability of the models under study, we use the Press–Schechter formalism to derive their expected redshift distribution of cluster-size halos that will be provided by future X-ray and Sunyaev–Zeldovich cluster surveys. We find that the Hubble flow differences between the Liouville and the LambdaCDM models provide a significantly different halo redshift distribution, suggesting that the models can be observationally distinguished.

► We investigate the effect of dilaton dark energy (Liouville scenario) on the Universe expansion. ► Joint likelihood analysis of supernovae type-Ia, galaxy ages and baryon acoustic oscillations. ► Tight constraints on the main cosmological parameters are set. ► The Liouville cosmological model growth rates match well with the observed growth rate. ► Models can be observationally distinguished through redshift distribution of cluster-size halos.

Related Topics
Physical Sciences and Engineering Physics and Astronomy Astronomy and Astrophysics
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