Speaker
Description
When the spontaneous breaking of the Peccei-Quinn (PQ) symmetry occurred, the
resulting angular direction of the PQ field, i.e. the axion could have possessed an initial nonzero velocity arising from additional terms that explicitly break the PQ symmetry. This opens
up the possibility for smaller values of the decay constant than in the conventional scenario.
We elaborate further on the outcome of this “kinetic misalignment” framework, assuming that
axions form the entirety of the dark matter abundance. The kinetic misalignment framework
possesses a weak limit in which the axion field starts to oscillate at the same temperature as
in the conventional scenario, and a strong limit corresponding to large initial velocities which
delay the onset of oscillations. We show how this scenario impacts the formation of axion
miniclusters, and we sketch the details of these substructures along with potential detecting
signatures.
