Prompt cusps of dark matter halos
Abstract
The onset of the formation of dark matter halos in the early universe was marked by the monolithic collapse of smooth peaks in the density field. This process creates prompt rho ~ r^-1.5 density cusps, which persist largely unaltered through the subsequent growth phases of their halos. Consequently, a prompt cusp is expected to reside at the center of every halo and subhalo. In annihilating dark matter models, the abundance of these features and the high density inside them greatly influence the intensity and morphology of the annihilation signal. Moreover, the properties of prompt cusps are closely linked to details of the primordial density field. In warm dark matter models, prompt cusps are expected to be large enough to influence dwarf galaxy kinematics at detectable levels.