2008/09/30 by S. Basilakos, Spyros Basilakos, Georgios Lukes-Gerakopoulos +1 · 1 citation
Physics and Astronomy · #Astrophysics #Baryon acoustic oscillations #Chaplygin gas #Classical mechanics #Cosmology #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Dark energy #Dark matter #Galaxies: Formation, Evolution, Phenomena #Hubble's law #Lambda-CDM model #Metric expansion of space #Physics #Scalar field #Scale factor (cosmology) #Theoretical physics #astro-ph
paper · pdf · doi:10.1103/physrevd.78.083509
published as Phys.Rev.D78:083509,2008 · 11 pages, 7 figures, published in Physical Review D, 78, 083509, (2008)
openalex publication_date 2008/10/06 · arxiv created 2008/11/25 · arxiv updated 2010/04/23 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We study the dynamics of the scalar field Friedmann-Lemaitre-Robertson-Walker flat cosmological models within the framework of the unified dark matter (UDM) scenario. In this model we find that the main cosmological functions such as the scale factor of the Universe, the scalar field, the Hubble flow, and the equation of state parameter are defined in terms of hyperbolic functions. These analytical solutions can accommodate an accelerated expansion, equivalent to either the dark energy or the standard \ensuremathΛ models. Performing a joint likelihood analysis of the recent supernovae type Ia data and the baryonic acoustic oscillations traced by the Sloan Digital Sky Survey galaxies, we place tight constraints on the main cosmological parameters of the UDM cosmological scenario. Finally, we compare the UDM scenario with various dark energy models namely \ensuremathΛ cosmology, parametric dark energy model and variable Chaplygin gas. We find that the UDM scalar field model provides a large and small scale dynamics which are in fair agreement with the predictions by the above dark energy models although there are some differences especially at high redshifts.