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Assuming Galactic positrons do not go far before annhilating, a differencebetween the observed 511 keV annihilation flux distribution and that ofpositron production, expected from beta-plus decay in Galactic ironnucleosynthesis, was evoked as evidence of a new source and a signal of darkmatter. We show, however, that the dark mater sources can not account for theobserved positronium fraction without extensive propagation. Yet with suchpropagation, standard nucleosynthetic sources can fully account for the spatialdifferences and the positronium fraction, leaving no signal for dark mater toexplain.

Is There a Dark Matter Signal in the Galactic Positron Annihilation Radiation?