2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/4674Density profiles of cosmological virialized systems, or dark halos, have recently attracted much attention. I first present a brief historical review of numerical simulations to quantify the halo density profiles. Then I describe the latest results on the universal density profile and their observational confrontation. Finally I discuss a clustering model of those halos with particular emphasis on the cosmological light-cone effect.invited review to appear in the proceedings of "Matter and Energy in Clusters of Galaxies", edited by S. Bowyer and C.-Y. HwangAstrophysicstext