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 , 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 , and -wave annihilation leads to a core density nearly independent of halo mass, which seems consistent with observations.
- Received 11 May 2000
DOI:https://doi.org/10.1103/PhysRevLett.85.3335
©2000 American Physical Society