The Milky Way's rotation curve with superfluid dark matter
  Recent studies have shown that dark matter with a superfluid phase in which
phonons mediate a long-distance force gives rise to the phenomenologically
well-established regularities of Modified Newtonian Dynamics (MOND). Superfluid
dark matter, therefore, has emerged as a promising explanation for
astrophysical observations by combining the benefits of both particle dark
matter and MOND, or its relativistic completions, respectively. We here
investigate whether superfluid dark matter can reproduce the observed Milky Way
rotation curve for $ R < 25\,\rm{kpc}$ and are able to answer this question in
the affirmative. Our analysis demonstrates that superfluid dark matter fits the
data well with parameters in reasonable ranges. The most notable difference
between superfluid dark matter and MOND is that superfluid dark matter requires
about $ 20\% $ less total baryonic mass (with a suitable interpolation
function). The total baryonic mass is then $5.96 \cdot 10^{10}\,M_\odot$, of
which $1.03\cdot10^{10}\,M_\odot$ are from the bulge,
$3.95\cdot10^{10}\,M_\odot$ are from the stellar disk, and
$0.98\cdot10^{10}\,M_\odot$ are from the gas disk. Our analysis further allows
us to estimate the radius of the Milky Way's superfluid core (concretely, the
so-called NFW and thermal radii) and the total mass of dark matter in both the
superfluid and the normal phase. By varying the boundary conditions of the
superfluid to give virial masses $M_{200}^{\rm{DM}}$ in the range
$0.5-3.0\cdot10^{12}\,M_\odot$, we find that the NFW radius $R_{\rm{NFW}}$
varies between $65\,\rm{kpc}$ and $73\,\rm{kpc}$, while the thermal radius
$R_T$ varies between about $67\,\rm{kpc}$ and $105\,\rm{kpc}$. This is the
first such treatment of a non-spherically-symmetric system in superfluid dark
matter.
