Cosmological Measurements from Angular Power Spectra Analysis of BOSS DR12 Tomography

TL;DR

This paper analyzes the angular power spectra of BOSS DR12 galaxies to constrain cosmological parameters, combining these with Planck and supernova data, and demonstrates the method's effectiveness for future surveys.

Contribution

The study introduces a tomographic angular power spectrum analysis of BOSS DR12 galaxies, providing competitive cosmological constraints and showcasing its potential for future large-scale surveys.

Findings

Constrained dark energy equation-of-state with ~4% error.

Measured cosmological parameters consistent with previous results.

Set an upper limit of 0.14 eV on the sum of neutrino masses.

Abstract

We constrain cosmological parameters by analysing the angular power spectra of the Baryon Oscillation Spectroscopic Survey DR12 galaxies, a spectroscopic follow-up of around 1.3 million SDSS galaxies over 9,376 deg$^2$ with an effective volume of $\sim 6.5$ (Gpc $h^{-1}$)$^3$ in the redshift range $0.15 \leq z < 0.80$. We split this sample into 13 tomographic bins ($\Delta z = 0.05$); angular power spectra were calculated using a Pseudo-$C_{\ell}$ estimator, and covariance matrices were estimated using log-normal simulated maps. Cosmological constraints obtained from these data were combined with constraints from Planck CMB experiment as well as the JLA supernovae compilation. Considering a $w$CDM cosmological model measured on scales up to $k_{max} = 0.07h$ Mpc$^{-1}$, we constrain a constant dark energy equation-of-state with a $\sim 4\%$ error at the 1-$\sigma$ level: $w_0 = -0.993^{+0.046}_{-0.043}$, together with $\Omega_m = 0.330\pm 0.012$, $\Omega_b = 0.0505 \pm 0.002$, $S_8 \equiv \sigma_8 \sqrt{\Omega_m/0.3} = 0.863 \pm 0.016$, and $h = 0.661 \pm 0.012$. For the same combination of datasets, but now considering a $\Lambda$CDM model with massive neutrinos and the same scale cut, we find: $\Omega_m = 0.328 \pm 0.009$, $\Omega_b = 0.05017^{+0.0009}_{-0.0008}$, $S_8 = 0.862 \pm 0.017$, and $h = 0.663^{+0.006}_{-0.007}$ and a 95\% credible interval (CI) upper limit of $\sum m_{\nu} < 0.14$ eV for a normal hierarchy. These results are competitive if not better than standard analyses with the same dataset, and demonstrate this should be a method of choice for future surveys, opening the door for their full exploitation in cross-correlations probes.