Speaker
Description
Axion-dilaton models constitute a well-motivated and minimal class of theories that emerge in extra-dimensional completions of high-energy physics. These models naturally feature kinetic couplings between multiple scalar fields, which can have significant consequences in late-time cosmology. I will present the cosmological implications of these interactions when prescribing an axion and a dilaton field to describe dark matter and dark energy, respectively, including the predicted effects on the CMB, late time structure growth, and particle mass evolution. I will show that these effects allow a resolution of the Hubble tension and the model to fake a phantom cross, fitting the recent DESI data as well as the phenomenological parameterisations, in a single minimal framework.