2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/61859We prove the existence of canonical scrolls; that is, scrolls playing the role of canonical curves. First of all, they provide the geometrical version of Riemann Roch Teorem: any special scroll is the projection of a canonical scroll and they allow to understand the classification of special scrolls in P3. Canonical scrolls correspond to the projective model of canonical geometrically ruled surfaces over a smooth curve. We also prove that the generic canonical scroll is projectively normal except in the hyperelliptic case and for very particular cases in the nonhyperelliptic situation.Latex2.09; 32 pagesAlgebraic GeometryPrimary, 14J26; Secondary, 14H25, 14H45text