Evolution of a domain wall in expanding universe: inflation and after it

A.D Dolgov,S.I Godunov,A.S Rudenko,V.E Volkova,V.A Matveev,Y.V Zhezher,D.G Levkov,V.A Rubakov

doi:10.1051/epjconf/201819108004

Abstract

We study the evolution of thick domain walls in the expanding universe. We have found that the domain wall evolution crucially depends on the time-dependent parameter C(t) = 1/(H(t)δ0)2, where H(t) is the Hubble parameter and δ0 is the width of the wall in flat space-time. For C(t) > 2 the physical width of the wall, a(t)δ(t), tends with time to constant value δ0, which is microscopically small. Otherwise, when C(t) ≤ 2, the wall steadily expands and can grow up to a cosmologically large size.

Highlights

Creation of the baryon asymmetry of the universe and possible existence of the cosmological antimatter crucially depends upon the version of C and CP violation realized in the early universe
This beautiful model, suffers from the domain wall problem [2]. To avoid this problem the mechanism of the wall destruction was proposed, see e.g. [3] and references therein. Another problem of the baryogenesis based on spontaneous CP violation is the width of the wall
We have found that at inflationary epoch the width of the domain walls exponentially rises when the parameter C(t) is smaller than the critical value C = 2

Summary

Introduction

Creation of the baryon asymmetry of the universe and possible existence of the cosmological antimatter crucially depends upon the version of C and CP violation realized in the early universe. In this connection spontaneous CP violation suggested in paper [1] is of particular interest. Another problem of the baryogenesis based on spontaneous CP violation is the width of the wall. We show that there exists some range of the inflation parameters leading to a large domain separation prior to baryogenesis This talk is based on papers [5, 6]

Evolution of thick domain walls in de Sitter universe

Evolution of thick domain walls in inflationary universe

Conclusions