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arXiv · 1503.04923

Is there evidence for dark energy evolution?

Xuheng Ding·Marek Biesiada·Shuo Cao·Zhengxiang Li·Zong-Hong Zhu
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Abstract

Recently, Sahni, Shafielo o & Starobinsky (2014) combined two independent measurements of $H(z)$ from BAO data with the value of the Hubble constant $H_0 = H(z=0)$, in order to test the cosmological constant hypothesis by means of an improved version of the $Om$ diagnostic. Their result indicated a considerable tension between observations and predictions of the $Λ$CDM model. However, such strong conclusion was based only on three measurements of $H(z)$. This motivated us to repeat similar work on a larger sample. By using a comprehensive data set of 29 $H(z)$, we find that discrepancy indeed exists. Even though the value of $Ω_{m,0} h^2$ inferred from $Omh^2$ diagnostic depends on the way one chooses to make a summary statistics (weighted mean or the median), the persisting discrepancy supports the claims of Sahni, Shafielo o & Starobinsky (2014) that $Λ$CDM model may not be the best description of our Universe.

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Xuheng Ding, Marek Biesiada, Shuo Cao, Zhengxiang Li, Zong-Hong Zhu. 2015-04-20. Is there evidence for dark energy evolution?. https://doi.org/10.1088/2041-8205%2F803%2F2%2Fl22

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