Now showing items 1-2 of 2

  • Extension of maps defined on many fibres 

    Barja Yáñez, Miguel Ángel; Naranjo, J. C. (1997)
    Article
    Open Access
    Let S be a fibred surface. We prove that the existence of morphisms from non countably many fibres to curves implies, up to base change, the existence of a rational map from S to another surface fibred over the same base ...
  • On the topological index of irregular surfaces 

    Barja Yáñez, Miguel Ángel; Naranjo, J. C.; Pirola, Gian Pietro (2005)
    Article
    Open Access
    We study the topological index of some irregular surfaces that we call generalized Lagrangian. We show that under certain hypotheses on the base locus of the Lagrangian system the topological index is non-negative. For ...