Hard gamma-ray emission from primordial black hole haloes around massive objects

Discovery of primordial black holes (PBHs) or more stringent upper limit on their number would have a great impact on the existing cosmological theories and provide better understanding of conditions in the early Universe, including the spectrum of density and metric fluctuations and cold dark matter models. We consider possible strategies of searching for the high-energy Hawking radiation from evaporating PBHs. Specifically, we analyze the capture of cold dark matter species (especially PBHs) during the formation of gravitationally bound objects. Among all the objects considered, large (M⩾105 M⊙), nearby (within ∼5 kpc from the Sun) globular clusters are shown to provide the best prospects for detection of the black holes.