What is half a neutrino? Reviewing cosmological constraints on neutrinos and dark radiation

• Published in: Publications of the Astronomical Society of Australia
• Main Authors: Riemer-Sørensen, S., Parkinson, D., Davis, T. M.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press 2013
• Subjects: Cosmological parameters; Cosmology: observations; Early Universe; Elementary particles; Neutrinos; Big-bang nucleosynthesis; South-pole telescope; Power spectrum; Primordial abundance; Massive neutrinos; Model; Galaxies; Clusters; Detector; Search; 1912 Space and Planetary Science; 3103 Astronomy and Astrophysics; South Pole; South pole
• Online Access: https://espace.library.uq.edu.au/view/UQ:305864

Neutrinos are one of the major puzzles in modern physics. Despite measurements of mass differences, the Standard Model of particle physics describes them as exactly massless. Additionally, recent measurements from both particle physics experiments and cosmology indicate the existence of more than the three Standard Model species. Here, we review the cosmological evidence and its possible interpretations.