Dark Radiation candidates after Planck
Eleonora Di Valentino, Alessandro Melchiorri, Olga Mena
TL;DR
Recent Planck CMB data tightens constraints on relativistic species in the early universe, enabling analysis of sterile neutrinos, axions, and dark sector models with additional light particles.
Contribution
This paper reviews updated bounds on models with relativistic particles using the latest Planck CMB measurements.
Findings
Neff constrained to 3.62^{+0.50}_{-0.48} at 95% CL
Limits placed on sterile neutrino models
Constraints on hadronic axion and extended dark sector models
Abstract
Recent Cosmic Microwave Background (CMB) results from the Planck satellite, combined with previous CMB data and Hubble constant measurements from the Hubble Space Telescope, provide a constraint on the effective number of relativistic degrees of freedom of Neff=3.62^{+0.50}_{-0.48} at 95% CL. These new measurements provide a unique opportunity to place limits on models containing relativistic species at the decoupling epoch. Here we review the bounds or the allowed parameter regions in sterile neutrino models, hadronic axion models as well as on extended dark sectors with additional light species based on the latest Planck CMB observations.
Peer Reviews
No public reviews on file for this paper yet. If you reviewed it on a platform where reviews are public (OpenReview, ICLR, NeurIPS, ICML), you can paste yours below so the community can read it here.
Videos
No videos yet. Explain this paper in a talk, walkthrough, or lecture? Add one.