Observational constraints to a unified cosmological model

Abstract

We propose a phenomenological unified model for dark matter and dark energy based on an equation of state parameter $w$ that scales with the $\arctan$ of the redshift. The free parameters of the model are three constants: ${\Omega }_{b0}$, $\alpha$ and $\beta$. Parameter $\alpha$ dictates the transition rate between the matter dominated era and the accelerated expansion period. The ratio $\beta /\alpha$ gives the redshift of the equivalence between both regimes. Cosmological parameters are fixed by observational data from Primordial Nucleosynthesis (PN), Supernovae of the type Ia (SNIa), Gamma-Ray Bursts (GRB) and Baryon Acoustic Oscillations (BAO). The calibration of the 138 GRBs events is performed using the 580 SNIa of the Union2.1 data set and a new set of 79 high-redshift GRBs is obtained. The various sets of data are used in different combinations to constraint the parameters through statistical analysis. The unified model is compared to the $\Lambda$CDM model and their differences are emphasized.

Original version: 15 pages, 9 figures, 7 tables. Current version: matches the published paper; 14 pages, 9 figures, 4 tables

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Cited by in corpus (6)

• Model-independent distance calibration of high-redshift gamma-ray bursts and constrain on the $\Lambda$CDM model
• Are long gamma-ray bursts standard candles?
• $f\left(R,{\nabla }_{{\mu }_1}R,\dots ,{\nabla }_{{\mu }_1}\dots {\nabla }_{{\mu }_n}R\right)$ theories of gravity in Einstein frame: A higher order modified Starobinsky inflation model in the Palatini approach
• Consistency of nonlinear interacting ghost dark energy with recent observations
• Analytic Study of Cosmological Perturbations in a Unified Model of Dark Matter and Dark Energy with a Sharp Transition
• Early-Matter-Like Dark Energy and the Cosmic Microwave Background