Constraints on cold dark matter accelerating cosmologies and cluster formation
Contribuinte(s) |
UNIVERSIDADE DE SÃO PAULO |
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Data(s) |
18/04/2012
18/04/2012
2010
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Resumo |
We discuss the properties of homogeneous and isotropic flat cosmologies in which the present accelerating stage is powered only by the gravitationally induced creation of cold dark matter (CCDM) particles (Omega(m) = 1). For some matter creation rates proposed in the literature, we show that the main cosmological functions such as the scale factor of the universe, the Hubble expansion rate, the growth factor, and the cluster formation rate are analytically defined. The best CCDM scenario has only one free parameter and our joint analysis involving baryonic acoustic oscillations + cosmic microwave background (CMB) + SNe Ia data yields (Omega) over tilde = 0.28 +/- 0.01 (1 sigma), where (Omega) over tilde (m) is the observed matter density parameter. In particular, this implies that the model has no dark energy but the part of the matter that is effectively clustering is in good agreement with the latest determinations from the large- scale structure. The growth of perturbation and the formation of galaxy clusters in such scenarios are also investigated. Despite the fact that both scenarios may share the same Hubble expansion, we find that matter creation cosmologies predict stronger small scale dynamics which implies a faster growth rate of perturbations with respect to the usual Lambda CDM cosmology. Such results point to the possibility of a crucial observational test confronting CCDM with Lambda CDM scenarios through a more detailed analysis involving CMB, weak lensing, as well as the large-scale structure. CNPq[304792/2003-9] FAPESP[04/13668-0] |
Identificador |
PHYSICAL REVIEW D, v.82, n.2, 2010 1550-7998 http://producao.usp.br/handle/BDPI/15659 10.1103/PhysRevD.82.023504 |
Idioma(s) |
eng |
Publicador |
AMER PHYSICAL SOC |
Relação |
Physical Review D |
Direitos |
restrictedAccess Copyright AMER PHYSICAL SOC |
Palavras-Chave | #DECAYING VACUUM ENERGY #LUMINOUS RED GALAXIES #DIGITAL SKY SURVEY #PARTICLE CREATION #BULK VISCOSITY #GENERAL-RELATIVITY #KINEMATIC TESTS #PHOTON CREATION #CHAPLYGIN-GAS #MODELS #Astronomy & Astrophysics #Physics, Particles & Fields |
Tipo |
article original article publishedVersion |