Revisiting constraints on asymmetric dark matter from collapse in white
  dwarf stars
  The runaway collapse phase of a small dark matter cluster inside a white
dwarf star encompasses a reversible stage, where heat can be transferred back
and forth between nuclear and dark matter. Induced nuclear burning phases are
stable and early carbon depletion undermines previous claims of type Ia
supernova ignition. Instead, mini black holes are formed at the center of the
star that either evaporate or accrete stellar material until a macroscopic
sub-Chandrasekhar-mass black hole is formed. In the latter case, a 0.1 to 1
second lasting electromagnetic transient signal can be detected upon ejection
of the white dwarf's potential magnetic field. Binary systems that transmute to
black holes and subsequently merge emit gravitational waves. Advanced
LIGO/Virgo should detect one such sub-Chandrasekhar binary black hole inspiral
per year, while future Einstein telescope-like facilities will detect thousands
per year. The effective spin parameter distribution is peaked at 0.2 and
permits future studies to disentangle from primordial sub-Chandrasekhar black
holes. Such signatures are compatible with current direct detection
constraints, as well as with neutron star constraints in the case of bosonic
dark matter, even though they remain in conflict with the fermionic case for
part of the parameter space.
