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Centro de Astrofísica da Universidade do Porto

Alternatives to quintessence model building

P. P. Avelino, L. M. G. Beça, J. P. M. de Carvalho, C. J. A. P. Martins, P. Pinto

We discuss the issue of toy model building for the dark energy component of the universe. Specifically, we consider two generic toy models recently proposed as alternatives to quintessence models, respectively known as Cardassian expansion and the Chaplygin gas. We show that the former is entirely equivalent to a class of quintessence models. We determine the observational constraints on the latter, coming from recent supernovae results and from the shape of the matter power spectrum. As expected, these restrict the model to a behavior that closely matches that of a standard cosmological constant Λ.

Physical Review D
Volume 67, Page 023511_1
January 2003

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