2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/141301We show in this paper by using the Wang-Landau flat-histogram Monte Carlo method that the phase transition in the XY stacked triangular antiferromagnet is clearly of first-order, confirming results from latest Monte Carlo simulation and from a nonperturbative renormalization group, putting an end to a long-standing controversial issue.7 pages, 3 figures, to appear in J. Appl. PhysStatistical Mechanicstext