Speaker
Raymond Volkas
(U of Melbourne)
Description
The standard DFSZ axion model features stable domain walls, so requires a pre-inflationary axion. This means the density of axion dark matter depends on an unknowable initial misalignment angle and thus predictivity is compromised compared to the post-inflationary axion case. I present a systematic classification of flavour-dependent DFSZ Peccei-Quinn symmetry variants that have no domain wall problem and thus permit a post-inflationary axion. I then introduce the VISHnu model, which connects the Peccei-Quinn sector to neutrino mass generation via the type-1 seesaw model and hence also features thermal leptogenesis. Aspects of the inflationary dynamics of the model are then presented.
