Preheating after Multi-Field Inflation

          @misc{ pirsa_PIRSA:09050067,
            doi = {10.48660/09050067},
            url = {https://pirsa.org/09050067},
            author = {Battefeld, Thorsten},
            keywords = {Cosmology},
            language = {en},
            title = {Preheating after Multi-Field Inflation},
            publisher = {Perimeter Institute},
            year = {2009},
            month = {may},
            note = {PIRSA:09050067 see, \url{https://pirsa.org}}
          }
          

Abstract

We investigate the feasibility of explosive particle production via parametric resonance or tachyonic preheating in multi-field inflationary models by means of lattice simulations. We observe a strong suppression of resonances in the presence of four-leg interactions between the inflaton fields and a scalar matter field, leading to insufficient preheating when more than two inflatons couple to the same matter field. This suppression is caused by a dephasing of the inflatons that increases the effective mass of the matter field. Including three-leg interactions leads to tachyonic preheating, which is not suppressed by an increase in the number of fields. If four-leg interactions are sub-dominant, we observe a slight enhancement of tachyonic preheating. Thus, in order for preheating after multi-field inflation to be efficient, one needs to ensure that three-leg interactions are present. If no tachyonic contributions exist, we expect the old theory of reheating to be applicable.