Study of galaxy distributions with SDSS DR14 data and measurement of neutrino masses

TL;DR

This study uses SDSS DR14 data and simulations to constrain neutrino masses by analyzing galaxy distributions and cosmological parameters within the $ ext{Lambda}$CDM model, providing a measurement of the sum of neutrino masses.

Contribution

It presents a novel combined analysis of galaxy data and cosmological models to estimate neutrino masses, accounting for various parameters and uncertainties.

Findings

Estimated sum of neutrino masses: 0.719 ± 0.312 eV

Consistent measurements of power spectrum amplitude and spectral index

Derived galaxy bias including scale dependence

Abstract

We study galaxy distributions with Sloan Digital Sky Survey SDSS DR14 data and with simulations searching for variables that can constrain neutrino masses. To be specific, we consider the scenario of three active neutrino eigenstates with approximately the same mass, so $\sum m_\nu = 3 m_\nu$. Fitting the predictions of the $\Lambda$CDM model to the Sachs-Wolfe effect, $\sigma_8$, the galaxy power spectrum $P_\textrm{gal}(k)$, fluctuations of galaxy counts in spheres of radii ranging from $16/h$ to $128/h$ Mpc, BAO measurements, and $h = 0.678 \pm 0.009$, in various combinations, with free spectral index $n$, and free galaxy bias and galaxy bias slope, we obtain consistent measurements of $\sum m_\nu$. The results depend on $h$, so we have presented confidence contours in the $(\sum m_\nu, h)$ plane. A global fit with $h = 0.678 \pm 0.009$ obtains $\sum m_\nu = 0.719 \pm 0.312 \textrm{ (stat)}^{+0.055}_{-0.028} \textrm{ (syst)}$ eV, and the amplitude and spectral index of the power spectrum of linear density fluctuations $P(k)$: $N^2 = (2.09 \pm 0.33) \times 10^{-10}$, and $n = 1.021 \pm 0.075$. The fit also returns the galaxy bias $b$ including its scale dependence.