2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/198764We discuss the equivalence of two dual scalar field theories in 2 dimensions. The models are derived though the elimination of different fields in the same Freedman--Townsend model. It is shown that tree $S$-matrices of these models do not coincide. The 2-loop counterterms are calculated. It turns out that while one of these models is single-charged, the other theory is multi-charged. Thus the dual models considered are non-equivalent on classical and quantum levels. It indicates the possibility of the anomaly leading to non-equivalence of dual models.14 pages, LaTeX; 2 figures, encapsulated PostScriptHigh Energy Physics - Theorytext