Updating non-standard neutrinos properties with Planck-CMB data and full-shape analysis of BOSS and eBOSS galaxies

TL;DR

This paper combines Planck-CMB data with galaxy power spectrum measurements from BOSS and eBOSS to constrain non-standard neutrino properties within extended cosmological models, finding no deviations from standard predictions and setting the strongest limits to date.

Contribution

It provides the first comprehensive observational constraints on extended neutrino properties using combined CMB and galaxy data, improving parameter bounds significantly.

Findings

No evidence for non-standard neutrino properties.

Most robust constraints from CMB + BOSS data.

Strongest limits ever reported on extended neutrino parameters.

Abstract

Using the latest observational data from Planck-CMB and its combination with the pre-reconstructed full-shape (FS) galaxy power spectrum measurements from the BOSS DR12 sample and eBOSS LRG DR16 sample, we report the observational constraints on the cosmic neutrino properties given by the extended $\Lambda$CDM scenario: $\Lambda$CDM + $N_{\rm eff}$ + $\sum m_{\nu}$ + $c^2_{\rm eff}$ + $c^2_{\rm vis}$ + $\xi_{\nu}$, and its particular case $\Lambda$CDM + $c^2_{\rm eff}$ + $c^2_{\rm vis}$ + $\xi_{\nu}$, where $N_{\rm eff}$, $\sum m_{\nu}$, $c^2_{\rm eff}$, $c^2_{\rm vis}$, $\xi_{\nu}$ are the effective number of species, the total neutrino mass, the sound speed in the neutrinos rest frame, the viscosity parameter and the degeneracy parameter quantifying a cosmological leptonic asymmetry, respectively. We observe that the combination of FS power spectrum measurements with the CMB data significantly improves the parametric space of the models compared to the CMB data alone case. We find no evidence for neutrinos properties other than the ones predicted by the standard cosmological theory. Our most robust observational constraints are given by CMB + BOSS analysis. For the generalized extended $\Lambda$CDM scenario, we find $c^2_{\rm eff}=0.3304^{+0.0064}_{-0.0075}$, $c^2_{\rm vis}=0.301^{+0.037}_{-0.033}$, $\xi_{\nu} < 0.05$, $N_{\rm eff}=2.90 \pm 0.15$ at 68\% CL, with $\sum m_{\nu} < 0.116$ eV at 95\% CL. These are the strongest limits ever reported for these extended $\Lambda$CDM scenarios.