Fermilab Theory Seminars

Reflections on the Matter-Dark Matter Coincidence

by Dr Arushi Bodas (Fermilab/UChicago)

US/Central
Curia II

Curia II

Description

The striking similarity between the cosmic abundances of baryons and dark matter, despite their very different astrophysical behavior, strongly motivates the scenario in which dark matter resides within a dark sector that mirrors the structure of the standard model. The coincidence is then explained by an approximate Z_2 exchange symmetry between the two sectors, where the dark matter consists of stable dark neutrons, with matter and dark matter asymmetries arising via parallel WIMP baryogenesis mechanisms. I will present a higher-dimensional realization in the UV, in which the hierarchical couplings of the two sectors and the requisite Z_2-breaking structure arise naturally. I will show how the model can be made compatible with cosmology while maintaining naturalness and emphasise certain potential pitfalls not fully considered in previous literature.