Dissipative dark matter and the rotation curves of dwarf galaxies
  There is ample evidence from rotation curves that dark matter halos around
disk galaxies have nontrivial dynamics. Of particular significance are: a) the
cored dark matter profile of disk galaxies, b) correlations of the shape of
rotation curves with baryonic properties, and c) Tully-Fisher relations. Dark
matter halos around disk galaxies may have nontrivial dynamics if dark matter
is strongly self interacting and dissipative. Multicomponent hidden sector dark
matter featuring a massless `dark photon' (from an unbroken dark $U(1)$ gauge
interaction) which kinetically mixes with the ordinary photon provides a
concrete example of such dark matter. The kinetic mixing interaction
facilitates halo heating by enabling ordinary supernovae to be a source of
these `dark photons'. Dark matter halos can expand and contract in response to
the heating and cooling processes, but for a sufficiently isolated halo could
have evolved to a steady state or `equilibrium' configuration where heating and
cooling rates locally balance. This dynamics allows the dark matter density
profile to be related to the distribution of ordinary supernovae in the disk of
a given galaxy. In a previous paper a simple and predictive formula was derived
encoding this relation. Here we improve on previous work by modelling the
supernovae distribution via the measured UV and $H\alpha$ fluxes, and compare
the resulting dark matter halo profiles with the rotation curve data for each
dwarf galaxy in the LITTLE THINGS sample. The dissipative dark matter concept
is further developed and some conclusions drawn.
