APEC Seminar (Astronomy - Particle Physics - Experimental Physics - Cosmology)

Speaker: Adam Smith (Sheffield University)
Title: Axion-dilaton interactions in the dark sector
Date (JST): Thu, Jan 15, 2026, 13:30 - 15:00
Place: Seminar Room A
Abstract:
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.