Early-Universe Model Building

Abstract

Theoretical investigations into the evolution of the early universe are an essential part of particle physics that allow us to identify viable extensions to the Standard Model as well as motivated parameter space that can be probed by various experiments and observations. In this white paper, we review particle physics models of the early universe. First, we outline various models that explain two essential ingredients of the early universe (dark matter and baryon asymmetry) and those that seek to address current observational anomalies. We then discuss dynamics of the early universe in models of neutrino masses, axions, and several solutions to the electroweak hierarchy problem. Finally, we review solutions to naturalness problems of the Standard Model that employ cosmological dynamics.

contribution to Snowmass 2021

Cited by in corpus (5)

• Probing Physics Beyond the Standard Model: Limits from BBN and the CMB Independently and Combined
• Detection of Early-Universe Gravitational Wave Signatures and Fundamental Physics
• Confronting Dark Matter Freeze-In during Reheating with Constraints from Inflation
• Free-Streaming Neutrinos and Their Phase Shift in Current and Future CMB Power Spectra
• On Sphaleron Heating in the Presence of Fermions