Cosmic Neutrinos and Other Light Relics

Abstract

Cosmological measurements of the radiation density in the early universe can be used as a sensitive probe of physics beyond the standard model. Observations of primordial light element abundances have long been used to place non-trivial constraints on models of new physics and to inform our understanding of the thermal history to the first few minutes of our present phase of expansion. Precision measurements of the angular power spectrum of the cosmic microwave background temperature and polarization will drastically improve our measurement of the cosmic radiation density over the next decade. These improved measurements will either uncover new physics or place much more stringent constraints on physics beyond the standard model, while pushing our understanding of the early universe to much earlier times.

4 pages. Based on a presentation given at Rencontres de Moriond Cosmology 2016 which reported on arXiv:1508.06342 and Green, Meyers, van Engelen 2016 (forthcoming). To appear in Rencontres de Moriond Conference Proceedings

References in corpus (5)

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• A New Target for Cosmic Axion Searches
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• Multi-wavelength constraints on the inflationary consistency relation