Inflation and Phenomenology in an Extended Two-Higgs-Doublet-Model

Abstract

The Two-Higgs-Doublet-Standard Model-Axion-Seesaw-Higgs-Portal Inflation (2hdSMASH) model containing two Higgs doublets, a Standard Model (SM) singlet complex scalar and three SM singlet right-handed Majorana neutrinos addresses the following shortcomings of the SM: i) dark matter by axions, ii) strong CP problem by the Peccei-Quinn mechanism, iii) neutrino masses and mixing by the seesaw mechanism, iv) baryon asymmetry by thermal leptogenesis and v) inflation by Higgs portal inflation. In this thesis we investigate the inflationary aspects of 2hdSMASH and its subsequent impact on low energy phenomenology. In particular, we identify four inflationary directions whose parameter values required for successful inflation do not violate perturbative unitarity and vacuum stability conditions. By analyzing the Renormalization-Group (RG) flow of the parameters we identify the constraints from thermal leptogenesis, baryon asymmetry, vacuum stability, perturbative unitarity and Higgs phenomenology. Satisfying all of these constraints ensures a consistent picture of our universe from the electroweak all the way up to the Planck scale. We determine typical benchmark points satisfying theoretical and experimental constraints which can be potentially probed by future colliders.