1806.06781
Model independent $H(z)$ reconstruction using the cosmic inverse distance ladder
Lemos, Lee, Efstathiou, Gratton
Recent distance ladder determinations of the Hubble constant H0 disagree at about the 3.5 sigma level with the value determined from Planck measurements of the CMB assuming LCDM cosmology. This discrepancy has prompted speculation that new physics might be required beyond that assumed in the LCDM model. In this paper, apply the inverse distance ladder to fiat a parametric form of H(z) to BAO and SN Ia data together with priors on the sound horizon at the end of the radiation drag epoch, r_d. Apply priors on the r_d, based on inferences from either Planck or WMAP, and demonstrate that these values are consistent with CMB-independent determinations of r_d derived from measurements of the primordial deuterium abundance, BAO and SNe data assuming the LCDM cosmology. The H(z) constraints that were derived are independent of detailed physics within the dark sector at low z, relying only on the validity of the FRW metric of GR. For each assumed prior on r_d, find consistency with the inferred value of H0 and the Planck LCDM value and corresponding tension with the distance ladder estimate.
Model independent $H(z)$ reconstruction using the cosmic inverse distance ladder
Lemos, Lee, Efstathiou, Gratton
Recent distance ladder determinations of the Hubble constant H0 disagree at about the 3.5 sigma level with the value determined from Planck measurements of the CMB assuming LCDM cosmology. This discrepancy has prompted speculation that new physics might be required beyond that assumed in the LCDM model. In this paper, apply the inverse distance ladder to fiat a parametric form of H(z) to BAO and SN Ia data together with priors on the sound horizon at the end of the radiation drag epoch, r_d. Apply priors on the r_d, based on inferences from either Planck or WMAP, and demonstrate that these values are consistent with CMB-independent determinations of r_d derived from measurements of the primordial deuterium abundance, BAO and SNe data assuming the LCDM cosmology. The H(z) constraints that were derived are independent of detailed physics within the dark sector at low z, relying only on the validity of the FRW metric of GR. For each assumed prior on r_d, find consistency with the inferred value of H0 and the Planck LCDM value and corresponding tension with the distance ladder estimate.
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