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Annihilating Cold Dark Matter

M. Kaplinghat·L. Knox·M. S. Turner
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Abstract

Structure formation with cold dark matter (CDM) predicts halos with a central density cusp, which are observationally disfavored. If CDM particles have an annihilation cross section sigma*v ~ 10**(-29) (m/GeV) cm**2, then annihilations will soften the cusps. We discuss plausible scenarios for avoiding the early Universe annihilation catastrophe that could result from such a large cross section. The predicted scaling of core density with halo mass depends upon the velocity dependence of sigma*v, and s-wave annihilation leads to a core density nearly independent of halo mass, which seems consistent with observations.

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M. Kaplinghat, L. Knox, M. S. Turner. 2000-08-29. Annihilating Cold Dark Matter. https://doi.org/10.1103/physrevlett.85.3335

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