Vortex Structures in a Rotating BEC Dark Matter Component
  We study the effects of a dark matter component that consists of bosonic
particles with ultralight masses in the condensed state. We compare previous
studies for both non-interacting condensates and with repulsive two-body terms
and show consistency between the proposals. Furthermore, we explore the effects
of rotation on a superfluid dark matter condensate, assuming that a vortex
lattice forms as seen in ultracold atomic gas experiments. The influence of
such a lattice in virialization of gravitationally bound structures and on
galactic rotation velocity curves is explored. With fine-tuning of the bosonic
particle mass and the two-body repulsive interaction strength, we find that one
can have sub-structure on rotation curves that resembles some observations in
spiral galaxies. This occurs when the dark matter halo has an array of hollow
cylinders. This can cause oscillatory behavior in the galactic rotation curves
in similar fashion to the well-known effect of the spiral arms. We also
consider how future experiments and numerical simulations with ultracold atomic
gases could tell us more about such exotic dark matter proposals.
