Refining the multi-field effects of Higgs inflation

Abstract

In this thesis, I investigated the extent to which the inclusion of multiple scalar fields in models of Higgs inflation produces observable departures from the single field case. I designed simulations to numerically solve the differential equations of motion in the Einstein frame governing the evolution of two nonminimally coupled fields in a quartic potential. Determining the behavior of the Hubble parameter, I found that successful inflation results in this model from a range of initial conditions. Based on calculations of the evolution of field perturbations by Courtney Peterson and Max Tegmark [6], the results suggest that the turn rate of the fields' combined velocity through field space has been sufficiently small since Hubble crossing that it may be excluded as a source of the amplification of perturbations in the Cosmic Microwave Background to their present size.