Internal Bremsstrahlung Signature of Real Scalar Dark Matter and
  Consistency with Thermal Relic Density
  A gamma-ray excess from the galactic center consistent with line emission
around 130 GeV was recently found in the Fermi-LAT data. Although the Fermi-LAT
Collaboration has not confirmed its significance, such a signal would be a
clear signature of Dark Matter annihilation. Until now, there have been many
attempts to explain the excess by Dark Matter. However these efforts tend to
give too-small cross sections into photons if consistency with the correct
thermal relic density of Dark Matter is required. In this letter, we consider a
simple Yukawa interaction that can be compatible with both aspects and show
which parameters are favored.
