2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/150354We show for the moduli space of rank-2 coherent sheaves on an algebraic surface that there exists a 'dual' moduli space. This dual space allows a construction of the first one without using the GIT construction. Furthermore, we obtain a Barth-morphism, generalizing the concept of jumping lines. This morphism is by construction a finite morphism.12 pages LaTeX using pb-diagram.styAlgebraic Geometrytext