  An analytical solution for the discrepancy between observed core-like
profiles and predicted cusp profiles in dark matter halos is studied. We
calculate the distribution function for Navarro-Frenk-White halos and extract
energy from the distribution, taking into account the effects of baryonic
physics processes. We show with a simple argument that we can reproduce the
evolution of a cusp to a flat density profile by a decrease of the initial
potential energy.
