Axion braneworld cosmology

Understand

We study axion cosmology in a 5D Universe, in the case of flat and warped extra dimension.

• The comparison between theoretical predictions and observations constrains the 5D axion decay constant and the 5D Planck mass, which has to be taken into account in building 5D axion models.
• The framework developed in this paper can be readily applied to other bulk fields in brane universes.