Annihilation radiation of dark matter in heterotic orbifold models

We investigate the prospects for indirect detection of neutralino dark matter in the context of effective supergravity theories derived from the heterotic superstring. These models provide a consistent framework linking fundamental high-energy theory with low energy physics, and a phenomenology in the gaugino and scalar sector, which is considerably different from the commonly discussed case of minimal Supergravity. We show that astrophysical observations, in particular with gamma-ray experiments like GLAST and HESS, will provide significant constraints on combinations of astrophysical and particle physics parameters, and interesting clues on the SUSY breaking mechanism.