Positrons from Dark Matter annihilation in the galactic halo: uncertainties

Indirect detection signals from dark matter annihilation are studied in the positron channel. The positron propagation inside the galactic medium is calculated in a two-zone diffusion model and the astrophysical uncertainties on the positron DM signal are derived. We obtain dark matter scenarios and propagation models that nicely fit existing data on the positron fraction and show that running or planned space experiments have the potential to discriminate a possible signal from the background and, in some cases, to distinguish among different astrophysical propagation models.