Density profiles of dark matter haloes on Galactic and Cluster scales
  In the present paper, we improve the "Extended Secondary Infall Model" (ESIM)
of Williams et al. (2004) to obtain further insights on the cusp/core problem.
The model takes into account the effect of ordered and random angular momentum,
dynamical friction and baryon adiabatic contraction in order to obtain a
secondary infall model more close to the collapse reality. The model is applied
to structures on galactic scales (normal and dwarf spiral galaxies) and on
cluster of galaxies scales. The results obtained suggest that angular momentum
and dynamical friction are able, on galactic scales, to overcome the competing
effect of adiabatic contraction eliminating the cusp. The NFW profile can be
reobtained, in our model only if the system is constituted just by dark matter
and the magnitude of angular momentum and dynamical friction are reduced with
respect to the values predicted by the model itself. The rotation curves of
four LSB galaxies from de Blok & Bosma (2002) are compared to the rotation
curves obtained by the model in the present paper obtaining a good fit to the
observational data. On scales smaller than $\simeq 10^{11} h^{-1} M_{\odot}$
the slope $\alpha \simeq 0$ and on cluster scales we observe a similar
evolution of the dark matter density profile but in this case the density
profile slope flattens to $\alpha \simeq 0.6$ for a cluster of $\simeq 10^{14}
h^{-1} M_{\odot}$. The total mass profile, differently from that of dark
matter, shows a central cusp well fitted by a NFW model.
