Speaker
Description
If the nano-Hz gravitational wave signal observed by Pulsar Timing Array (PTA) experiments originates from a strongly supercooled first-order phase transition, the resulting supercooling at ${\cal O}(1)$ GeV temperature necessitates a new mechanism for generating the baryon asymmetry and dark matter, as any pre-existing abundances are diluted. We propose a model of cold darkogenesis, where the winding number changing dynamics of a dark $SU(2)_{\rm D}$ Higgs field generate a dark asymmetry, subsequently transferred to the visible sector via neutron portal interactions. The scenario naturally explains the baryon asymmetry, asymmetric self-interacting dark matter, and the PTA signal, and will be tested in collider and direct detection experiments.
