Halo growth and the NFW profile
  We perform a simple test showing that accreting halos grow inside-out and
have density profiles that are statistically indistinguishable from those of
halos having undergone major mergers. The test also reveals that the ability
for the NFW analytical expression to fit the density profile of halos spoils
towards large masses at any redshift. On view of these results, we analyze the
M-c relations on extreme mass and redshift domains predicted by usual toy
models based on numerical data and one physical model based on the two
assumptions above confirmed by the test.
