  I propose a modification of the spherical infall model for the evolution of
density fluctuations with initially Gaussian probability distribution and
scale-free power spectra in Einstein-de Sitter universe as developed by Hoffman
& Shaham. I introduce a generalized form of the initial density distribution
around an overdense region and cut it off at half the inter-peak separation
accounting in this way for the presence of the neighbouring fluctuations.
Contrary to the original predictions of Hoffman & Shaham the resulting density
profiles within virial radii no longer have power-law shape but their steepness
increases with distance. The profiles of halos of galactic mass are well fitted
by the universal profile formula of changing slope obtained as a result of
N-body simulations by Navarro, Frenk & White. The trend of steeper profiles for
smaller masses and higher spectral indices is also reproduced. The agreement
between the model and simulations is better for smaller masses and lower
spectral indices which suggests that galaxies form mainly by accretion while
formation of clusters involves merging.
