2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/54738This is a brief introduction on the graduate level to recent ideas in the Weinberg $(j,0)\oplus (0,j)$ formalism, appearing after presentation of the Bargamann-Wightman-Wigner-type quantum field theory by D. V. Ahluwalia {\it et al.}ReVTeX file, 15pp., 1 figure (EPS file), in SpanishHigh Energy Physics - Theorytext