2012/10/08 by Signe Riemer-Sørensen, Signe Riemer-Sorensen, David Parkinson +3 · 39 citations
Physics and Astronomy · #Cold dark matter #Cosmic microwave background #Cosmological model #Cosmology #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Dark matter #Neutrino #Neutrino Physics Research #Physics beyond the Standard Model #Standard Model (mathematical formulation) #astro-ph.CO #hep-ph
paper · pdf · doi:10.1088/0004-637x/763/2/89
published in The Astrophysical Journal 763(2), 89 (IOP Publishing) · 6 pages, 5 figures, submitted to ApJ
arxiv created 2012/10/08 · openalex publication_date 2013/01/14 · arxiv updated 2015/06/11 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
Recent indications from both particle physics and cosmology suggest the possible existence of more than three neutrino species. In cosmological analyses the effects of neutrino mass and number of species can in principle be disentangled for fixed cosmological parameters. However, since we do not have perfect measurements of the standard Λ cold dark matter model parameters, some correlation remains between the neutrino mass and number of species, and both parameters should be included in the analysis. Combining the newest observations of several cosmological probes (cosmic microwave background, large-scale structure, expansion rate), we obtain N eff = 3.58 +0.15 −0.16 (68% CL) +0.55 −0.53 (95% CL) and ∑ m ν < 0.60 eV(95% CL), which are currently the strongest constraints on N eff and ∑ m ν from an analysis including both parameters. The preference for N eff >3 is at the 2σ level.