A matter-dominated cosmological model with variable $G$ and $Λ$. Confrontation of theoretical predictions with observational data

Details A matter-dominated cosmological model with variable $G$ and $Λ$. Confrontation of theoretical predictions with observational data A matter-dominated cosmological model with variable $G$ and $Λ$. Confrontation of theoretical predictions with observational data

2011-04-15

arxiv.org/abs/1104.3029v2

Astronomy and Astrophysics

Astrophysics

Cosmology and Extragalactic Astrophysics

31 pages, 9 figures

Scientific paper

In the framework of renormalization-group improved cosmologies, we analyze both theoretically and observationally the exact and general solution of the matter-dominated cosmological equations, using the expression of \Lambda = \Lambda(G) already determined by the integration method employed in a previous paper. A rough comparison between such a model and the concordance \LambdaCDM model as to the magnitude-redshift relationship has been already done, without showing any appreciable differences. We here perform a more refined study of how astrophysical data (Union2 set) on type-I supernovae, gamma ray bursts (in a sample calibrated in a model independent way with the SneIa dataset), and gas fraction in galaxy clusters (using a sample of Chandra measurements of the X-ray gas mass fraction) affect the model and constrain its parameters. We also apply a cosmographic approach to our cosmological model and estimate the cosmographic parameters by fitting both the supernovae and the gamma ray bursts datasets. We show that this matter-dominated cosmological model with variable Newton parameter and variable cosmological term is indeed compatible with the observations above (on type Ia supernovae, the gamma ray bursts Hubble diagram, and the gas mass fraction in X-ray luminous galaxy clusters). The cosmographic approach adopted confirms such conclusions. Finally, it seems possible to include radiation into the model, since numerical integration of the equations derived by the presence of both radiation and matter shows that, after inflation, the total density parameter is initially dominated by the radiation contribution and later by the matter one.

Affiliated with

Also associated with

No associations

Rating

A matter-dominated cosmological model with variable $G$ and $Λ$. Confrontation of theoretical predictions with observational data does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with A matter-dominated cosmological model with variable $G$ and $Λ$. Confrontation of theoretical predictions with observational data, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A matter-dominated cosmological model with variable $G$ and $Λ$. Confrontation of theoretical predictions with observational data will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-8802