GUT Baryogenesis after Preheating

At the end of inflation the universe is frozen in a near zero-entropy state with energy density in a coherent scalar field and must be “defrosted” to produce the observed entropy and baryon number. We propose that the baryon asymmetry is generated by the decay of supermassive Grand Unified Theory (GUT) bosons produced non-thermally in a preheating phase after inflation. We show that baryogenesis is possible for an inflaton masses of order 10 13 GeV and a GUT Higgs boson mass of order 10 14 GeV, thus solving many drawbacks facing GUT baryogenesis in the old reheating scenario.