Speaker
Description
We introduce a mechanism by which a misaligned ALP can be dynamically converted into a dark photon in the presence of a background dark magnetic field. An abundance of non-relativistic ALPs will produce dark photons with momentum of order the inhomogeneities in the background field; therefore a highly homogeneous field will produce non-relativistic dark photons without relying on any redshifting of their momenta. The analysis naturally splits into two regimes. In the large field regime the dark photons exhibit the `gliding' phenomena in which their energy density decays slower than matter. In the smaller field regime the energy density converts to dark photons, and during a time in which one would naively assume the field is frozen by Hubble friction, the energy density decays like radiation.
