2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/15957The scaling properties of the free energy and some of universal amplitudes of a group of models belonging to the universality class of the quantum nonlinear sigma model and the O(n) quantum $ϕ^4$ model in the limit $n\to \infty$ as well as the quantum spherical model, with nearest-neighbor and long-range interactions (decreasing at long distances $r$ as $1/r^{d+σ}$) is presented.6 pages, 3 figures, Bogolubov conference: "Problems of theoretical and mathematical physics", Moscow 1999, RussiaStatistical Mechanicstext