Exotic Compact Objects: The Dark White Dwarf
  Several dark matter models allow for the intriguing possibility of exotic
compact object formation. These objects might have unique characteristics that
set them apart from their baryonic counterparts. Furthermore, gravitational
wave observations of their mergers may provide the only direct window on a
potentially entirely hidden sector. Here we discuss dark white dwarfs, starting
with an overview of the microphysical model and analytic scaling relations of
macroscopic properties derived from the non-relativistic limit. We use the full
relativistic formalism to confirm these scaling relations and demonstrate that
dark white dwarfs, if they exist, would have masses and tidal deformabilities
that are very different from those of baryonic compact objects. Further, and
most importantly, we demonstrate that dark white dwarf mergers would be
detectable by current or planned gravitational observatories across several
orders of magnitude in the particle-mass parameter space. Lastly, we find
universal relations analogous to the compactness-Love and binary Love relations
in neutron star literature. Using these results, we show that gravitational
wave observations would constrain the properties of the dark matter particles
constituting these objects.
