The Hubble constant and sound horizon from the late-time Universe. (arXiv:2006.16692v1 [astro-ph.CO])

The Hubble constant and sound horizon from the late-time Universe. (arXiv:2006.16692v1 [astro-ph.CO])
<a href="http://arxiv.org/find/astro-ph/1/au:+Zhang_X/0/1/0/all/0/1">Xue Zhang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Huang_Q/0/1/0/all/0/1">Qing-Guo Huang</a>

We measure the expansion rate of the recent Universe and the calibration
scale of the baryon acoustic oscillation (BAO) from low-redshift data. BAO
relies on the calibration scale, i.e., the sound horizon at the end of drag
epoch $r_d$, which often imposes a prior of the cosmic microwave background
(CMB) measurement from the Planck satellite. In order to make really
independent measurements of $H_0$, we leave $r_d$ completely free and use the
BAO datasets combined with the 31 observational $H(z)$ data (OHD) and GW170817.
For the two model-independent reconstructions of $H(z)$, we obtain
$H_0=69.66^{+5.88}_{-6.63}$ km s$^{-1}$ Mpc$^{-1}$,
$r_d=148.56^{+3.65}_{-4.08}$ Mpc in the cubic expansion, and $H_0=71.13pm2.91$
km s$^{-1}$ Mpc$^{-1}$, $r_d=148.48^{+3.73}_{-3.74}$ Mpc in the polynomial
expansion, and we find that the values of sound horizon $r_d$ are consistent
with the estimate derived from the Planck CMB data assuming a flat $Lambda$CDM
model.

We measure the expansion rate of the recent Universe and the calibration
scale of the baryon acoustic oscillation (BAO) from low-redshift data. BAO
relies on the calibration scale, i.e., the sound horizon at the end of drag
epoch $r_d$, which often imposes a prior of the cosmic microwave background
(CMB) measurement from the Planck satellite. In order to make really
independent measurements of $H_0$, we leave $r_d$ completely free and use the
BAO datasets combined with the 31 observational $H(z)$ data (OHD) and GW170817.
For the two model-independent reconstructions of $H(z)$, we obtain
$H_0=69.66^{+5.88}_{-6.63}$ km s$^{-1}$ Mpc$^{-1}$,
$r_d=148.56^{+3.65}_{-4.08}$ Mpc in the cubic expansion, and $H_0=71.13pm2.91$
km s$^{-1}$ Mpc$^{-1}$, $r_d=148.48^{+3.73}_{-3.74}$ Mpc in the polynomial
expansion, and we find that the values of sound horizon $r_d$ are consistent
with the estimate derived from the Planck CMB data assuming a flat $Lambda$CDM
model.

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