2016/06/01 by Jing-Zhao Qi, Qi, Jing-Zhao, Ming-Jian Zhang +3
Physics and Astronomy · #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #astro-ph.CO #gr-qc
paper · pdf · doi:10.48550/arxiv.1606.00168
arxiv created 2016/06/10 · arxiv updated 2016/06/13
Om(z) is a diagnostic approach to distinguish dark energy models. However, there are few articles to discuss what is the distinguishing criterion. In this paper, firstly we smooth the latest observational H(z) data using a model-independent method -- Gaussian processes, and then reconstruct the Om(z) and its fist order derivative L(1)m. Such reconstructions not only could be the distinguishing criteria, but also could be used to estimate the authenticity of models. We choose some popular models to study, such as ΛCDM, generalized Chaplygin gas (GCG) model, Chevallier-Polarski-Linder (CPL) parametrization and Jassal-Bagla-Padmanabhan (JBP) parametrization. We plot the trajectories of Om(z) and L(1)m with 1 σ confidence level of these models, and compare them to the reconstruction from H(z) data set. The result indicates that the H(z) data does not favor the CPL and JBP models at 1 σ confidence level. Strangely, in high redshift range, the reconstructed L(1)m has a tendency of deviation from theoretical value, which demonstrates these models are disagreeable with high redshift H(z) data. This result supports the conclusions of Sahni et al. \citepsahni2014model and Ding et al. \citepding2015there that the ΛCDM may not be the best description of our universe.