The next cosmology seminar take place on Friday 4th of April, room E349 at 10:00am. We will have the pleasure to listen to Siyao Li from the Institute of Science (Tokyo, Japan) and the Institute of Basic Science (Daejeon, South Korea).
At 10:00am, room E349, Siyao Li will be talking about
Classical oscillon decay accelerated by external scalar field resonance
Oscillons are long-lived, spherical solitons that arise in real scalar field theories with potential flatter than quadratic. They are considered to form via parametric resonance during preheating after inflation and the energy of the inflaton field can be stored in oscillons. Because of their long lifetime, they can play an important role in the early universe, especially in the reheating process. However, the estimation of their lifetime is greatly affected by considering the coupling of the inflaton field to other fields. We investigate the impact of an external real scalar filed coupled to an oscillon on its decay and lifetime. We find the external scalar field can grow exponentially on the inhomogeneous oscillon background due to parametric resonance. We find this exponential growth can destroy oscillon structure very rapidly when the coupling is very strong. Interestingly, we also find an unexpected large intermediate coupling regime where the decay of oscillon is only temporarily accelerated by the massive external field.