Diffuse gamma-ray background and cosmic-ray positrons from annihilating dark matter

Understand

We study the annihilating dark matter contribution to the extra-galactic diffuse gamma-ray background spectrum, motivated by the recent observations of cosmic-ray positron/electron anomalies.

• The observed diffuse gamma-ray flux provides stringent constraint on dark matter models and we present upper bounds on the annihilation cross section of the dark matter.
• It is found that for the case of cored dark matter halo profile, the diffuse gamma-rays give more stringent bound compared with gamma-rays from the Galactic center.
• The Fermi satellite will make the bound stronger.