A new series of moduli components of rank-2 semistable sheaves on with singularities of mixed dimension

Abstract

We construct a new infinite series of irreducible components of the Gieseker-Maruyama moduli scheme , , of semistable rank-2 sheaves on with Chern classes , and , whose general points are sheaves with singularities of mixed dimension. These sheaves are constructed by elementary transformations of stable and properly -semistable reflexive sheaves along disjoint unions of collections of points and smooth irreducible curves which are rational or complete intersection curves in . As a special member of this series, we obtain a new component of . Bibliography: 12 titles.