Cosmography: Supernovae Union2, Baryon Acoustic Oscillation, observational Hubble data and Gamma ray bursts

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• 作者：Lixin Xup>ap>p> ; p>p>bp>p> ; p>p>cp>p> ; p>p>lxxu@dlut.edu.cn"" rel=""nofollowp> ; Yuting Wangp>ap>
• 关键词：Cosmography
• 刊名：Physics Letters B
• 出版年：2011
• 出版时间：11 August 2011
• 年：2011
• 卷：702
• 期：2-3
• 页码：114-120
• 全文大小：277 K

文摘

In this Letter, a parametrization describing the kinematical state of the universe via cosmographic approach is considered, where the minimum input is the assumption of the cosmological principle, i.e. the Friedmann–Robertson–Walker metric. A distinguished feature is that the result does not depend on any gravity theory and dark energy models. As a result, a series of cosmographic parameters (deceleration parameter q₀, jerk parameter j₀ and snap parameter s₀) are constrained from the cosmic observations which include type Ia supernovae (SN) Union2, the Baryon Acoustic Oscillation (BAO), the observational Hubble data (OHD), the high redshift Gamma ray bursts (GRBs). By using Markov Chain Monte Carlo (MCMC) method, we find the best fit values of cosmographic parameters in 1σ regions: , , and which are improved remarkably. The values of q₀ and j₀ are consistent with flat ΛCDM model in 1σ region. But the value of s₀ of flat ΛCDM model will go beyond the 1σ region.