Matter power spectrum for the generalized Chaplygin gas model: The Newtonian approach

Journal Article · Sat Nov 15 04:00:00 EST 2008 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.78.103523· OSTI ID:21250898

Fabris, J C; Goncalves, S V. B.; Velten, H E. S.; Zimdahl, W ^[1]

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1. Universidade Federal do Espirito Santo, Departamento de Fisica, Av. Fernando Ferrari, 514, Campus de Goiabeiras, CEP 29075-910, Vitoria, Espirito Santo (Brazil)

We model the cosmic medium as the mixture of a generalized Chaplygin gas and a pressureless matter component. Within a neo-Newtonian approach (in which, different from standard Newtonian cosmology, the pressure enters the homogeneous and isotropic background dynamics) we compute the matter power spectrum. The 2dFGRS data are used to discriminate between unified models of the dark sector (a purely baryonic matter component of roughly 5% of the total energy content and roughly 95% generalized Chaplygin gas) and different models, for which there is separate dark matter, in addition to that accounted for by the generalized Chaplygin gas. Leaving the corresponding density parameters free, we find that the unified models are strongly disfavored. On the other hand, using unified model priors, the observational data are also well described, in particular, for small and large values of the generalized Chaplygin gas parameter {alpha}. The latter result is in agreement with a recent, more qualitative but fully relativistic, perturbation analysis in [V. Gorini, A. Y. Kamenshchik, U. Moschella, O. F. Piatella, and A. A. Starobinsky, J. Cosmol. Astropart. Phys. 02 (2008) 016.].

• OSTI ID: 21250898
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 10 Vol. 78; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BARYONS
COSMOLOGY
DENSITY
DISTURBANCES
MIXTURES
NONLUMINOUS MATTER
PERTURBATION THEORY
RELATIVISTIC RANGE
SIMULATION
SPECTRA
UNIFIED MODEL