Baryon Asymmetries In A Natural Inflation Model

This master degree dissertation is a collection and exhibition of the two works I have done with my supervisor during the time as a graduate student.The first work is about the baryon asymmetry and reheating process in the early universe, it had been done before the end of 2014, and have been published in Physical Review D. The second one is a research about the light quark energy loss problems, which we started at the end of 2014 and have not finished yet.In the first part of this paper, we studied a mechanism that can achieve the baryon asymmetry in a natural inflation model. By assuming the inflaton to be a complex scalar field with a weakly broken U(1) symmetry, the baryon asymmetry generation was easily unified with the stage of inflation and reheating.This mechanism was first developed in the chaotic inflation model, we extended it to a generalized natural inflation model, and compared our result with the original chaotic inflation model. Our result shows that the mechanism in a natural inflation model works equally well as in chaotic models.In the second part of this paper, we used the AdS/QCD correspondence to study the energy loss problem when a light quark interacts with the quark-gluon plasma. We calculated the thermalization distance of the quark, and worked out the instantaneous energy loss rate for the two di?erent prescriptions of jets in both the static and the expanding background.