Scalar field phenomenology in disformally-coupled quintessence

Robert Hagala (Universitetet i Oslo)

13 February 2019

The quintessence model is a simple alternative to GR, where a cosmological scalar field is responsible for the cosmic acceleration when rolling down a potential. Here, I consider an extension of this model by coupling the scalar field to matter through a disformal interaction. This introduces perturbations to the field evolution, as well as fifth forces acting on the matter distribution.

I present the model of disformally coupled quintessence, and discuss newly discovered phenomena in the evolution of the scalar field in this model. I will show results from recent N-body simulations, including the field evolution on non-linear scales, and the possibility for repulsive fifth forces.