Phase transitions in the embryo Universe

Abstract

Grand unified theories suggest that one or more phase transitions should occur when k T ≈ 10 14 GeV (T ≈ 10 27 K), which in standard cosmology would have occurred at t ≈ 10 -35 s. If such a transition happens quickly, then an unacceptably large number of magnetic monopoles would be produced. A slow transition would lead to an inflationary Universe, providing a possible solution to the horizon and flatness problems. However, the inflationary scenario requires a mechanism to trigger the phase transition. A suggestion made independently by Linde and by Albrecht & Steinhardt appears promising, but the details have not yet been worked out.