BAO signatures in the 2-point angular correlations and the Hubble tension

Abstract

An observational tension on estimates of the Hubble parameter, $H_0$, using early and late Universe information, is being of intense discussion in the literature. Additionally, it is of great importance to measure $H_0$ independently of CMB data and local distance ladder method. In this sense, we analyze 15 measurements of the transversal BAO scale, $\theta_{\rm BAO}$, obtained in a weakly model-dependent approach, in combination with other data sets obtained in a model-independent way, namely, Big Bang Nucleosynthesis (BBN) information, 6 gravitationally lensed quasars with measured time delays by the H0LiCOW team, and measures of cosmic chronometers (CC). We find $H_0 = 74.88_{-2.1}^{+1.9}$ km s${}^{-1}$ Mpc${}^{-1}$ and $H_0 = 72.06_{-1.3}^{+1.2}$ km s${}^{-1}$ Mpc${}^{-1}$ from $\theta_{BAO}$+BBN+H0LiCOW and $\theta_{BAO}$+BBN+CC, respectively, in fully accordance with local measurements. Moreover, we estimate the sound horizon at drag epoch, $r_{\rm d}$, independent of CMB data, and find $r_{\rm d}=144.1_{-5.5}^{+5.3}$ Mpc (from $\theta_{BAO}$+BBN+H0LiCOW) and $r_{\rm d} =150.4_{-3.3}^{+2.7}$ Mpc (from $\theta_{BAO}$+BBN+CC). In a second round of analysis, we test how the presence of a possible spatial curvature, $\Omega_k$, can influence the main results. We compare our constraints on $H_0$ and $r_{\rm d}$ with other reported values. Our results show that it is possible to use a robust compilation of transversal BAO data, $\theta_{BAO}$, jointly with other model-independent measurements, in such a way that the tension on the Hubble parameter can be alleviated.