The Physics of Light Relics

Cora Dvorkin; Joel Meyers; Peter Adshead; Mustafa Amin; Carlos A. Argüelles; Thejs Brinckmann; Emanuele Castorina; Timothy Cohen; Nathaniel Craig; David Curtin; Francis-Yan Cyr-Racine; Peizhi Du; Lloyd Knox; Bohua Li; Marilena Loverde; Kaloian Lozanov; Julian B. Muñoz; Katelin Schutz; Paul Shapiro; Benjamin Wallisch; Zachary J. Weiner; Weishuang Linda Xu

arXiv · 2203.07943

The Physics of Light Relics

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Abstract

Many well-motivated extensions of the Standard Model predict the existence of new light species that may have been produced in the early universe. Prominent examples include axions, sterile neutrinos, gravitinos, dark photons, and more. The gravitational influence of light relics leaves imprints in the cosmic microwave background fluctuations, the large-scale structure of the universe and the primordial element abundances. In this paper, we detail the physics of cosmological light relics, and describe how measurements of their relic density and mass serve as probes of physics beyond the Standard Model. A measurement of the light relic density at the precision of upcoming cosmological surveys will point the way toward new physics or severely constrain the range of viable extensions to the Standard Model.

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Cora Dvorkin, Joel Meyers, Peter Adshead, Mustafa Amin, Carlos A. Argüelles, Thejs Brinckmann, Emanuele Castorina, Timothy Cohen, Nathaniel Craig, David Curtin, Francis-Yan Cyr-Racine, Peizhi Du, Lloyd Knox, Bohua Li, Marilena Loverde, Kaloian Lozanov, Julian B. Muñoz, Katelin Schutz, Paul Shapiro, Benjamin Wallisch, Zachary J. Weiner, Weishuang Linda Xu. 2022-03-15. The Physics of Light Relics. https://arxiv.org/abs/2203.07943

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