Dark matter Inflationary production: dark photon and the QCD axion

by Michele Redi (INFN Florence)

Wednesday 30 Nov 2022, 15:00 → 16:00 Europe/Rome

1/1-2 - Aula "C. Voci" (Dipartimento di Fisica e Astronomia - Edificio Marzolo)

In the first part of this talk I will discuss dark photons obtained through the Higgs mechanism comparing with popular Stueckelberg theories. I will show how the dark matter abundance and the phenomenology depend on the details of inflation often re-introducing isocurvature perturbations. I will then consider the possibility that the Peccei-Quinn symmetry of the QCD axion is broken after the initial stages of inflation. In this scenario the population of axions from misalignment and inflationary fluctuations can be comparable. I will show that the strongest constraint on this scenario is due to Lyman-alpha forest observations rather than CMB. The large overdensities from inflation imply the existence of DM substructure.