2018/05/25 by Zahra Davari, M. Malekjani, Mohammad Malekjani +2 · 16 citations
Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Astrophysics #Barotropic fluid #Cosmology #Cosmology and Gravitation Theories #Dark energy #Dark fluid #Dark matter #Galaxies: Formation, Evolution, Phenomena #Galaxy #Parametrization (atmospheric modeling) #Particle physics #Physics #Quantum mechanics #Radiative transfer #Redshift #Scalar field dark matter #Theoretical physics #astro-ph.CO #gr-qc
paper · pdf · doi:10.1103/physrevd.97.123525
published in Physical review. D/Physical review. D. 97(12) (American Physical Society) · 11 pages, 7 figures and 2 tables. Accepted in PRD
arxiv created 2018/05/25 · openalex created_date 2018/06/01 · openalex publication_date 2018/06/14 · arxiv updated 2018/08/01 · openalex updated_date 2026/08/05
In this paper, we investigate a new phenomenological parametrization for unified dark matter and dark energy based on the polynomial expansion of the barotropic equation of state parameter w. Our parametrization provides a well-behaving evolution of w for both small and big redshifts as well as in the far future. The dark fluid described by our parametrization behaves for big redshifts like dark matter (DM). Therefore, one can parametrize dark energy and dark matter using a single dark fluid, like in the case of the Chaplygin gas. Within this parametrization, we consider two models: one with a dark energy (DE) barotropic parameter fixed to be \ensuremath-1 and the second one, where w\ensuremath≠\ensuremath-1 is chosen to match the best fit to the data. We study the main cosmological properties of these models at the expansion and perturbation levels. Based on the Markov chain Monte Carlo method with the currently available cosmic observational data sets, we constrain these models to determine the cosmological parameters at the level of the background and clustering of matter. We consider the interaction between dark matter and dark energy which directly affects the evolution of matter and its clustering. Our model appears to be perfectly consistent with the \mathrm\ensuremathΛCDM model, while providing unification of DE and DM.