Formation of Dark Matter Haloes in a Homogeneous Dark Energy Universe - Astrophysics > Cosmology and Nongalactic AstrophysicsReport as inadecuate




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Abstract: Several independent cosmological tests have shown evidences that the energydensity of the Universe is dominated by a dark energy component, which causethe present accelerated expansion. The large scale structure formation can beused to probe dark energy models, and the mass function of dark matter haloesis one of the best statistical tools to perform this study. We present here astatistical analysis of mass functions of galaxies under a homogeneous darkenergy model, proposed in the work of Percival 2005, using an observationalflux-limited X-ray cluster survey, and CMB data from WMAP. We compare, in ouranalysis, the standard Press-Schechter PS approach where a Gaussiandistribution is used to describe the primordial density fluctuation field ofthe mass function, and the PL Power Law mass function where we apply anonextensive q-statistical distribution to the primordial density field. Weconclude that the PS mass function cannot explain at the same time the X-rayand the CMB data even at 99% confidence level, and the PS best fit darkenergy equation of state parameter is $\omega=-0.58$, which is distant from thecosmological constant case. The PL mass function provides better fits to theHIFLUGCS X-ray galaxy data and the CMB data; we also note that the $\omega$parameter is very sensible to modifications in the PL free parameter, $q$,suggesting that the PL mass function could be a powerful tool to constrain darkenergy models.



Author: Lucio Marassi

Source: https://arxiv.org/



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