Baryogenesis and Inflation from the Higgs sector

Abstract

Although the ΛCDM model is the most complete model of modern cosmology to date, it still lacks a compelling description of the baryonic matter origin and of the cosmological inflationary period. In this thesis, we study the implications of the inflaton coupling to the Chern-Simons density in various scenarios, focusing on the role played by the Higgs sector in the baryogenesis and preheating capabilities. At first, we focus on the Higgs inflation model, as it relates cosmological observables to properties of electroweak physics, which makes the Higgs a candidate of particular interest for the inflaton. Then we propose a modified model of the latter, where the Higgs is combined with a new scalar field. Both fields participate in the inflation process in a unitary theory that predicts values of the cosmological observables in agreement with the results from the Planck/BICEP/Keck Collaborations. From a phenomenological perspective, this model can solve the Standard Model instability problem and, under some specified conditions, lead to the prediction of a TeV scale inflaton that could be produced and detected at the LHC. This model thus combines Higgs inflation, baryogenesis via production of helical magnetic fields, and stabilization of the Higgs potential by modifying the renormalization group running, to provide a successful history of the Universe.

Date of Award	28 Jul 2023
Original language	English
Supervisor	Mariano Quirós Carcelén (Director)