  We investigate a theory of dark matter called wave dark matter, also known as
scalar field dark matter (SFDM) and boson star dark matter or Bose-Einstein
condensate (BEC) dark matter, in spherical symmetry and its relation to the
Tully-Fisher relation. We show that fixing the oscillation frequency of wave
dark matter near the edge of dark galactic halos implies a Tully-Fisher-like
relation for those halos. We then describe how this boundary condition, which
is roughly equivalent to fixing the half-length of the exponentially decaying
tail of each galactic halo mass profile, may yield testable predictions for
this theory of dark matter.
