The structure of dark matter halos: self-similar models versus N-body simulations

We derive the density profile of cold dark matter halos using a self-similar accretion model. We show that if the clumpiness of the infalling matter is taken into account, then the inner density slope, d(log{rho})/d(log{r}), is close to -1. Compared with the density profiles predicted by different numerical simulations, we find that outside ~0.1% of the virial radius, our solutions agree best with the fitting formula proposed by Navarro et al. (2004), d(ln{rho})/d(ln{r})=-2(r/R)^0.17, where R is a characteristic radius, inside which the density profile becomes shallower than isothermal.