2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/53680These lecture notes provide an elementary introduction to the study of massless integrable quantum field theory in 1+1 dimensions using ``massless scattering''. Some previously unpublished results are also presented, including a non-perturbative study of Virasoro conserved quantities.30 pages + 2 figs includedHigh Energy Physics - Theorytext