Leptonic dark matter annihilation in the evolving universe: constraints and implications

Understand

The cosmic electron and positron excesses have been explained as possible dark matter (DM) annihilation products.

• In this work we investigate the possible effects of such a DM annihilation scenario during the evolution history of the Universe.
• We first calculate the extragalactic $\gamma$-ray background (EGRB), which is produced through the final state radiation of DM annihilation to charged leptons and the inverse Compton scattering between electrons/positrons and the cosmic microwave background.
• The DM halo profile and the minimal halo mass, which are not yet well determined from the current N-body simulations, are constrained by the EGRB data from EGRET and Fermi telescopes.