Model-independent test of the FLRW metric, the flatness of the Universe, and non-local measurement of $H_0$ [CEA]

Using measurements of $H(z)$ and $d_\mathrm{A}(z)$ from the Baryon Oscillation Spectroscopic Survey (BOSS) DR12 and luminosity distances from the Joint Lightcurve Analysis (JLA) compilation of supernovae, we test the Friedmann–Lema\^itre–Robertson–Walker (FLRW) metric and the flatness of the Universe in a model-independent way at two redshifts, namely 0.32 and 0.57. We then combine these observables to measure $H_0$ without any model assumption. Our measurement of $H_0 r_\mathrm{d} = 10075.23 \pm 269.20$ km s$^{-1}$ is consistent with Planck constrains for the flat $\Lambda$CDM model. Assuming $r_\mathrm{d} = 147.10$ Mpc, the fiducial value used in the BOSS analysis, we then derive $H_0 = 68.49 \pm 1.83$ km s$^{-1}$ Mpc$^{-1}$, which is compatible with the expected value of $H_0$ assuming the concordance model of cosmology, but possibly in slight tension with some local measurements. We also report that higher expansion history rates $h(z)$ (among the possibilities) as well as lower-bound values of $H_0$ result in better internal consistency among the independent data ($H(z)$ and $d_\mathrm{A}(z)$ from BAO at $z=0.32$ and $z=0.57$ and $d_\mathrm{L}(z)$ from JLA) we used in this work. This can be interpreted as an interesting and independent support of Planck cosmology without using any cosmic microwave background data.

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B. LHuillier and A. Shafieloo
Thu, 23 Jun 16

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