Abstract
The decay and annihilation cross sections of dark matter particles may depend on the value of a chameleonic scalar field that both evolves cosmologically and takes different values depending on the local matter density. This possibility introduces a separation between the physics relevant for freeze-out and that responsible for dynamics and detection in the late universe. We investigate how such dark sector interactions might be implemented in a particle physics Lagrangian and consider how current and upcoming observations and experiments bound such dark matter candidates. A specific simple model allows for an increase in the annihilation cross section by a factor of between freeze-out and today, while more complicated models should also allow for scattering cross sections near the astrophysical bounds.
2 More- Received 31 August 2012
DOI:https://doi.org/10.1103/PhysRevD.86.123529
© 2012 American Physical Society