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arXiv · 0809.1523

Cosmic constraints rule out s-wave annihilation of light dark matter

Dominik R. G. Schleicher·Simon C. O. Glover·Robi Banerjee·Ralf S. Klessen
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Abstract

Light dark matter annihilating into electron-positron pairs emits a significant amount of internal bremsstrahlung that may contribute to the cosmic gamma-ray background. The amount of emitted gamma-rays depends on the dark matter clumping factor. Recent calculations indicate that this value should be of order $10^6-10^7$. That allows us to calculate the expected gamma-ray background contribution from dark matter annihilation. We find that the light dark matter model can be ruled out if a constant thermally-averaged cross section is assumed (s-wave annihilation). For more massive dark matter candidates like neutralinos, however, cosmic constraints are weaker.

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Dominik R. G. Schleicher, Simon C. O. Glover, Robi Banerjee, Ralf S. Klessen. 2009-01-12. Cosmic constraints rule out s-wave annihilation of light dark matter. https://doi.org/10.1103/physrevd.79.023515

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