Updated neutrino mass constraints from galaxy clustering and CMB lensing-galaxy cross-correlation measurements

TL;DR

This study refines constraints on the total neutrino mass by combining galaxy clustering and CMB lensing data, improving modeling of galaxy bias and covariance, and finds an upper limit of 0.14 eV at 95% confidence.

Contribution

It introduces a more accurate model for galaxy bias and covariance in combining galaxy clustering with CMB lensing data, enhancing neutrino mass constraints.

Findings

Upper limit on neutrino mass: <0.14 eV at 95% confidence

Full-shape galaxy clustering info is comparable to BAO in constraining cosmology

Including CMB lensing cross-correlation does not significantly tighten neutrino mass bounds

Abstract

We revisit cosmological constraints on the sum of the neutrino masses $\Sigma m_\nu$ from a combination of full-shape BOSS galaxy clustering [$P(k)$] data and measurements of the cross-correlation between Planck Cosmic Microwave Background (CMB) lensing convergence and BOSS galaxy overdensity maps [$C^{\kappa \text{g}}_{\ell}$], using a simple but theoretically motivated model for the scale-dependent galaxy bias in auto- and cross-correlation measurements. We improve upon earlier related work in several respects, particularly through a more accurate treatment of the correlation and covariance between $P(k)$ and $C^{\kappa \text{g}}_{\ell}$ measurements. When combining these measurements with Planck CMB data, we find a 95% confidence level upper limit of $\Sigma m_\nu<0.14\,{\rm eV}$, while slightly weaker limits are obtained when including small-scale ACTPol CMB data, in agreement with our expectations. We confirm earlier findings that (once combined with CMB data) the full-shape information content is comparable to the geometrical information content in the reconstructed BAO peaks given the precision of current galaxy clustering data, discuss the physical significance of our inferred bias and shot noise parameters, and perform a number of robustness tests on our underlying model. While the inclusion of $C^{\kappa \text{g}}_{\ell}$ measurements does not currently appear to lead to substantial improvements in the resulting $\Sigma m_{\nu}$ constraints, we expect the converse to be true for near-future galaxy clustering measurements, whose shape information content will eventually supersede the geometrical one.