2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/100030Problems associated with the Boltzmann collisional operator are unveiled and discussed. By careful investigation it is shown that collective effects of molecular collisions in the six-dimensional position and velocity space are more sophisticated than they appear to be.5 pages, 1 figuresFluid DynamicsData Analysis, Statistics and Probabilitytext