FaYin Wang1; ZiGao Dai1; Shi Qi2
Source Publicationresearchinastronomyandastrophysics
AbstractGeneralized Chaplygin gas (whose equation of state is p(GCG) = -A/rho(alpha)(GCG)) G was proposed as a candidate for unification of dark energy and dark matter. We investigate constraints on this model with the latest observed data. We test the model with type-la supernovae (SNe Ia), cosmic microwave background (CMB) anisotropy, X-ray gas mass fractions in clusters, and gamma-ray bursts (GRBs). We calibrate the GRB luminosity relations without assuming any cosmological models using SNe Ia. We show that GRBs can extend the Hubble diagram to higher redshifts (z > 6). The GRB Hubble diagram is well behaved and delineates the shape of the Hubble diagram well. We measure A(s) equivalent to A/rho(alpha+1)(GCG,0) = 0.68(-0.08)(+0.04) (where rho(GCG,0) is the energy density today) and alpha = 0.22(-0.13)(+0.15) at the sigma confidence level using all the datasets. Our results rule out the standard Chaplygin gas model (alpha = 1) at the 3 sigma confidence level. The Lambda CDM is allowed at the 2 sigma confidence level. We find that acceleration could have started at a redshift of z similar to 0.70. The concordance of the generalized Chaplygin gas model with the age estimate of an old high redshift quasar is found. In addition, we show that GRBs can break the degeneracy between the generalized Chaplygin gas model and the XCDM model.
Document Type期刊论文
Recommended Citation
GB/T 7714
FaYin Wang,ZiGao Dai,Shi Qi. constraintsongeneralizedchaplygingasmodelincludinggammaraybursts[J]. researchinastronomyandastrophysics,2009,9(5):547.
APA FaYin Wang,ZiGao Dai,&Shi Qi.(2009).constraintsongeneralizedchaplygingasmodelincludinggammaraybursts.researchinastronomyandastrophysics,9(5),547.
MLA FaYin Wang,et al."constraintsongeneralizedchaplygingasmodelincludinggammaraybursts".researchinastronomyandastrophysics 9.5(2009):547.
Files in This Item:
There are no files associated with this item.
Related Services
Recommend this item
Usage statistics
Export to Endnote
Google Scholar
Similar articles in Google Scholar
[FaYin Wang]'s Articles
[ZiGao Dai]'s Articles
[Shi Qi]'s Articles
Baidu academic
Similar articles in Baidu academic
[FaYin Wang]'s Articles
[ZiGao Dai]'s Articles
[Shi Qi]'s Articles
Bing Scholar
Similar articles in Bing Scholar
[FaYin Wang]'s Articles
[ZiGao Dai]'s Articles
[Shi Qi]'s Articles
Terms of Use
No data!
Social Bookmark/Share
All comments (0)
No comment.

Items in the repository are protected by copyright, with all rights reserved, unless otherwise indicated.