Secretly Asymmetric Dark Matter
  We study a mechanism where the dark matter number density today arises from asymmetries generated in the dark sector in the early universe, even though total dark matter number remains zero throughout the history of the universe. The dark matter population today can be completely symmetric, with annihilation rates above those expected from thermal WIMPs. We give a simple example of this mechanism using a benchmark model of flavored dark matter. We discuss the experimental signatures of this setup, which arise mainly from the sector that annihilates the symmetric component of dark matter. 
Prateek Agrawal, Can Kilic, Sivaramakrishnan Swaminathan, Cynthia   Trendafilova
hep-ph