UltraViolet Freeze-in
  If dark matter is thermally decoupled from the visible sector, the observed
relic density can potentially be obtained via freeze-in production of dark
matter. Typically in such models it is assumed that the dark matter is
connected to the thermal bath through feeble renormalisable interactions. Here,
rather, we consider the case in which the hidden and visible sectors are
coupled only via non-renormalisable operators. This is arguably a more generic
realisation of the dark matter freeze-in scenario, as it does not require the
introduction of diminutive renormalisable couplings. We examine general aspects
of freeze-in via non-renormalisable operators in a number of toy models and
present several motivated implementations in the context of Beyond the Standard
Model physics. Specifically, we study models related to the Peccei-Quinn
mechanism and Z' portals.
