Annihilating Asymmetric Dark Matter
  The relic abundance of particle and antiparticle dark matter (DM) need not be
vastly different in thermal asymmetric dark matter (ADM) models. By considering
the effect of a primordial asymmetry on the thermal Boltzmann evolution of
coupled DM and anti-DM, we derive the requisite annihilation cross section.
This is used in conjunction with CMB and Fermi-LAT gamma-ray data to impose a
limit on the number density of anti-DM particles surviving thermal freeze-out.
When the extended gamma-ray emission from the Galactic Center is reanalyzed in
a thermal ADM framework, we find that annihilation into $\tau$ leptons prefer
anti-DM number densities 1-4$\%$ that of DM while the $b$-quark channel prefers
50-100$\%$.
