Thermal Friction in Early Cosmology

Speaker: 
Kim Berghaus
Institution: 
Johns Hopkins University
Date: 
Wednesday, October 9, 2019
Time: 
11:00 am
Location: 
NS2 1201
Abstract:
Rolling scalar fields play an important role in understanding cosmology within a particle physics framework. Coupling a rolling scalar field to light degrees of freedom gives rise to a thermal friction which, if large enough, induces a thermal bath. In the context of inflation the presence of such a thermal bath has compelling consequences as it significantly alters the usual observables, leading to a suppression of the tensor-to-scalar ratio r and a unique prediction for non-gaussianities. In my talk, I will illuminate why the axion of a non-Abelian gauge group is the ideal candidate for generating the thermal friction and how it sets the stage for a minimal setup of warm inflation, as well as a potential solution to the Hubble tension.
Host: 
Julian Heeck