http://arxiv.org/abs/2112.13862
We present cosmological constraints on the sum of neutrino masses as a function of the neutrino lifetime, in a framework in which neutrinos decay into dark radiation after becoming non-relativistic. We find that in this regime the cosmic microwave background (CMB), baryonic acoustic oscillations (BAO) and (uncalibrated) luminosity distance to supernovae from the Pantheon catalog constrain the sum of neutrino masses $\sum m_\nu$ to obey $\sum m_\nu< 0.42$ eV at (95$\%$ C.L.). While the the bound has improved significantly as compared to the limits on the same scenario from {\it Planck} 2015, it still represents a significant relaxation of the constraints as compared to the stable neutrino case. We show that most of the improvement can be traced to the more precise measurements of low-$\ell$ polarization data in {\it Planck} 2018, which leads to tighter constraints on $\tau_{\rm reio}$ (and thereby on $A_s$), breaking the degeneracy arising from the effect of (large) neutrino masses on the amplitude of the CMB power spectrum.
G. Abellán, Z. Chacko, A. Dev, et. al.
Thu, 30 Dec 21
12/71
Comments: 24 pages, 8 figures, comments welcome!
You must be logged in to post a comment.