A unified dark sector cosmological model

RUIZ, ANDRÉS NICOLÁS; DOMÍNGUEZ, MARIANO JAVIER

La Plata, Buenos Aires, Argentina

Congreso; 52 Reunión Anual de la Asociación Argentina de Astronomía; 2009

We explore the consequences of the measurements of the equation of state of dark matter, Serra & Domínguez (2009), on the homogeneuos FRW Universe dynamics and build an alternative cosmological scenario to the concordance ΛCDM universe. The new paradigm is based on the introduction of an effective scalar field that obeys a barotropic equation of state p = ωρ with ω = −1/3, replacing the undetected components of the dark sector: dark matter (DM) and dark energy (DE or Λ). We compute a minimal set of cosmological parameters which allow us to reproduce several observational results such as baryon abundance, constrains on the age of the universe, the astronomical scale of distances and the high redshift supernovae and gamma-ray bursts data with a high degree of precision. However it should be emphasized that the new model is not accelerating, instead expands assymptotically towards an Einstein Static Universe. We also present a brief dynamical system analysis of this model showing his stable behaviour.