Annihilating Cold Dark Matter
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.
Cite
@article{arxiv.astro-ph/0005210,
title = {Annihilating Cold Dark Matter},
author = {M. Kaplinghat and L. Knox and M. S. Turner},
journal= {arXiv preprint arXiv:astro-ph/0005210},
year = {2010}
}
Comments
Matches version accepted for publication in Physical Review Letters. Included the effect of adiabatic expansion. Some changes in the abstract. Conclusions unchanged