Now showing items 1-6 of 6

  • Construction of families of curves from finite length graded modules 

    Ballico E; Bolondi G (1990)
    We construct particular families of projective space curves starting from finite length graded modules, exhibiting several phenomena of specializations. The main tool is the Rao construction via a free resolution of the module.
  • Curves of maximum genus in the range A and stick-figures 

    Ballico E; Bolondi G; Ellia Ph; Mirò Roig RM (1997)
    In this paper we show the existence of smooth connected space curves not contained in a surface of degree less than m, with genus maximal with respect to the degree, in half of the so-called range A. The main tool is a ...
  • Deficiency modules and specializations 

    Ballico E; Bolondi G (1990)
    Given a family of curves in the projective space we study how their deficiency modules can change. This has a geometrical translation in the problem of determining how the liaison class of a flat family of curves can change. ...
  • The Lazarsfeld-Rao problem for liaison classes of two-codimensional subschemes of Pn 

    Ballico E; Bolondi G; Migliore JC (1991)
    We show how to use all the machinery of liaison techniques for the study of two-codimensional subschemes of a smooth arithmetically Gorenstein subscheme of Pn.
  • Numerical invariants of rank-2 arithmetically buchsbaum sheaves 

    Ballico E; Bolondi G; Mirò Roig RM (1989)
    We study rank-2 reflexive sheaves on P3 whose sections are Buchsbaum curves, giving vanishing theorems for the cohomology and bounds and gaps for the existence range of their Chern classes. These results are applied to ...
  • The variety of module structures 

    Ballico E; Bolondi G (1990)
    Introduction. In this paper we study how is "structured" the set of curves of the projective space having assigned dimensions for the cohomology groups Hi (P3, Jx (t)). In particular, we show that almost always this locally ...