Publication Date:
2013-03-23
Description:
The constraints on the cold dark matter (CDM) model from Type Ia supernova (SNe Ia) data alone and baryon acoustic oscillation (BAO) data alone are similar, so it is worthwhile to compare their constraints on the property of dark energy. We apply the three-year Supernova Legacy Survey (SNLS3) compilation of 472 SNe Ia data, the BAO measurement of distance, the cosmic microwave background radiation data from the seven-year Wilkinson Microwave Anisotropy Probe ( WMAP 7) and the Hubble parameter data to study the effect of their different combinations on the fittings of cosmological parameters in the modified holographic dark energy model and the Chevallier–Polarski–Linder model. Neither BAO nor WMAP 7 data alone give good constraint on the equation of state parameter of dark energy, but both WMAP 7 data and BAO data help SNe Ia data break the degeneracies among the model parameters, hence tighten the constraint on the variation of equation of state parameter w a , and WMAP 7 data do the job a little better. Although BAO and WMAP 7 data provide reasonably good constraints on m and k , it is not able to constrain the dynamics of dark energy. On the other hand, SNe Ia data do not provide good constraints on m and k , but they provide good constraint on the dynamics of dark energy, especially the variation of the equation of state parameter of dark energy, so we need to combine SNe Ia with BAO and WMAP 7 data to probe the property of dark energy. The addition of H ( z ) data helps better constrain the geometry of the Universe k and the property of dark energy. For the SNLS SNe Ia data, the nuisance parameters α and β are consistent for all different combinations of the above data, and their impacts on the fittings of cosmological parameters are minimal. By fitting the data to different models, the CDM model is still consistent with all the observational data.
Print ISSN:
0035-8711
Electronic ISSN:
1365-2966
Topics:
Physics
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