2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/178599The mass function of primordial black holes created through the near-critical gravitational collapse is calculated in a manner fairly independent of the statistical distribution of underlying density fluctuation, assuming that it has a sharp peak on a specific scale. Comparing it with various cosmological constraints on their mass spectrum, some newly excluded range is found in the volume fraction of the region collapsing into black holes as a function of the horizon mass.9 pages. Typos corrected. To appear in Physical Review DGeneral Relativity and Quantum CosmologyAstrophysicstext