  By means of high-resolution N-body simulations we revisited the
dissipationless collapse scenario for galaxy formation. We considered both
single-component collapses and collapses of a cold stellar distribution in a
live dark matter halo. Single-component collapses lead to stellar systems whose
projected profiles are fitted very well by the Sersic R^(1/m) law with 3.6 < m
< 8. The stellar end-products of collapses in a dark matter halo are still well
described by the R^(1/m) law, but with 1.9 < m < 12, where the lowest m values
are obtained when the halo is dominant. In all the explored cases the profiles
at small radii deviate from their global best-fit R^(1/m) model, being
significantly flatter. The break-radius values are comparable with those
measured in `core' elliptical galaxies, and are directly related to the
coldness of the initial conditions. The dissipationless collapse of initially
cold stellar distributions in pre-existing dark matter haloes may thus have a
role in determining the observed weak homology of elliptical galaxies.
