Barreira, A. and Li, B. and Hellwing, W. A. and Lombriser, L. and Baugh, C. M. and Pascoli, S. (2014) 'Halo model and halo properties in Galileon gravity cosmologies.', Journal of cosmology and astroparticle physics., 2014 (04). 029.
We investigate the performance of semi-analytical modelling of large-scale structure in Galileon gravity cosmologies using results from N-body simulations. We focus on the Cubic and Quartic Galileon models that provide a reasonable fit to CMB, SNIa and BAO data. We demonstrate that the Sheth-Tormen mass function and linear halo bias can be calibrated to provide a very good fit to our simulation results. We also find that the halo concentration-mass relation is well fitted by a power law. The nonlinear matter power spectrum computed in the halo model approach is found to be inaccurate in the mildly nonlinear regime, but captures reasonably well the effects of the Vainshtein screening mechanism on small scales. In the Cubic model, the screening mechanism hides essentially all of the effects of the fifth force inside haloes. In the case of the Quartic model, the screening mechanism leaves behind residual modifications to gravity, which make the effective gravitational strength time-varying and smaller than the standard value. Compared to normal gravity, this causes a deficiency of massive haloes and leads to a weaker matter clustering on small scales. For both models, we show that there are realistic halo occupation distributions of Luminous Red Galaxies that can match both the observed large-scale clustering amplitude and the number density of these galaxies.
|Keywords:||Modified gravity, Cosmological simulations, Power spectrum, Dark energy theory.|
|Full text:||(NA) Not Applicable |
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|Publisher Web site:||http://dx.doi.org/10.1088/1475-7516/2014/04/029|
|Publisher statement:||© 2014 IOP Publishing Ltd. This is an author-created, un-copyedited version of an article accepted for publication in Journal of Cosmology and Astroparticle Physics. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at http://dx.doi.org/10.1088/1475-7516/2014/04/029.|
|Date accepted:||No date available|
|Date deposited:||No date available|
|Date of first online publication:||April 2014|
|Date first made open access:||No date available|
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