The 511 keV gamma emission from the galactic core may originate from a high concentration (similar to 10(22)) of primordial black holes (PBHs) in the core, each of whose Hawking radiation includes similar to 10(21) positrons per second. The PBHs we consider are taken as near the lightest with longevity greater than the age of the universe (mass similar to 10(12) kg; Schwarzschild radius similar to 1 fm). These PBHs contribute only a small fraction of cold dark matter, Omega(PBH) similar to 10(-8). This speculative hypothesis, if confirmed implies the simultaneous discovery of Hawking radiation and an early universe phase transition.
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