On the most constraining cosmological neutrino mass bounds

TL;DR

This paper uses recent cosmological data to set the tightest neutrino mass limit to date, challenging the inverted mass ordering and emphasizing the importance of future large-scale surveys.

Contribution

It provides the most stringent cosmological neutrino mass bound without priors on the Hubble constant, impacting neutrino mass hierarchy theories.

Findings

Neutrino mass sum constrained to <0.09 eV at 95% CL

Inverted mass ordering becomes less viable under these bounds

Highlights the role of upcoming spectroscopic surveys for relic neutrino detection

Abstract

We present here up-to-date neutrino mass limits exploiting the most recent cosmological data sets. By making use of the Cosmic Microwave Background temperature fluctuation and polarization measurements, Supernovae Ia luminosity distances, Baryon Acoustic Oscillation observations and determinations of the growth rate parameter, we are able to set the most constraining bound to date, $\sum m_\nu<0.09$ eV at $95\%$~CL. This very tight limit is obtained without the assumption of any prior on the value of the Hubble constant and highly compromises the viability of the inverted mass ordering as the underlying neutrino mass pattern in nature. The results obtained here further strengthen the case for very large multitracer spectroscopic surveys as unique laboratories for cosmological relics, such as neutrinos: that would be the case of the Dark Energy Spectroscopic Instrument (DESI) survey and of the Euclid mission.