Neutrino mass and dark energy constraints from redshift-space distortions

TL;DR

This paper combines galaxy power spectrum data with CMB and supernova observations to constrain neutrino masses and dark energy, highlighting the challenges posed by additional model parameters.

Contribution

It introduces advanced non-linear perturbation techniques to improve constraints on neutrino mass and dark energy from redshift-space distortions.

Findings

95% upper bound on neutrino mass is 180 meV with fixed dark energy parameters

Allowing dark energy parameters to vary increases the upper bound to 540 meV

Inclusion of galaxy bias parameters slightly weakens neutrino mass constraints

Abstract

Cosmology in the near future promises a measurement of the sum of neutrino masses, a fundamental Standard Model parameter, as well as substantially-improved constraints on the dark energy. We use the shape of the BOSS redshift-space galaxy power spectrum, in combination with CMB and supernova data, to constrain the neutrino masses and the dark energy. Essential to this calculation are several recent advances in non-linear cosmological perturbation theory, including FFT methods, redshift space distortions, and scale-dependent growth. Our 95% confidence upper bound of 180 meV on the sum of masses degrades substantially to 540 meV when the dark energy equation of state and its first derivative are also allowed to vary, representing a significant challenge to current constraints. We also study the impact of additional galaxy bias parameters, finding that a greater allowed range of scale-dependent bias only slightly shifts the preferred neutrino mass value, weakens its upper bound by about 20%, and has a negligible effect on the other cosmological parameters.