Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9953791 | Physics of the Dark Universe | 2018 | 7 Pages |
Abstract
The generalized Chaplygin gas could be considered as the unified dark fluid model because it might describe the past decelerating matter dominated era and at present time it provides an accelerating expansion of the Universe. In this paper, we employed the Planck 2015 cosmic microwave background anisotropy, type-Ia supernovae, observed Hubble parameter data sets to measure the full parameter space of the generalized Chaplygin gas as an unified dark matter and dark energy model. The model parameters Bs and α determine the evolutional history of this unified dark fluid model by influencing the energy density ÏGCG=ÏGCG0[Bs+(1âBs)aâ3(1+α)]1â(1+α). We assume the pure adiabatic perturbation of unified generalized Chaplygin gas. In the light of Markov Chain Monte Carlo method, we found that Bs=0.759â0.032â0.046+0.020+0.051 and α=0.0801â0.0801â0.0801+0.0208+0.1087 at 2Ï level. The model parameter α is very close to zero, the nature of GCG model is very similar to cosmological standard model ÎCDM.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Astronomy and Astrophysics
Authors
Hang Li, Weiqiang Yang, Yabo Wu,