English

Generic Syzygy Schemes

Algebraic Geometry 2007-05-23 v1 Commutative Algebra

Abstract

For a finite dimensional vector space G we define the k-th generic syzygy scheme Gensyz_k(G) by explicit equations. We show that the syzygy scheme Syz(f) of any syzygy in the linear strand of a projective variety X which is cut out by quadrics is a cone over a linear section of a corresponding generic syzygy scheme. We also give a geometric description of Gensyz_k(G) for k=0,1,2. In particular Gensyz_2(G) is the union of a Pl"ucker embedded Grassmannian and a linear space. From this we deduce that every smooth, non-degenerate projective curve C which is cut out by quadrics and has a p-th linear syzygy of rank p+3 admits a rank 2 vector bundle E with det E = O_C(1) and h^0(E) at least p+4.

Keywords

Cite

@article{arxiv.math/0403432,
  title  = {Generic Syzygy Schemes},
  author = {Hans-Christian Graf v. Bothmer},
  journal= {arXiv preprint arXiv:math/0403432},
  year   = {2007}
}

Comments

12 Pages. This paper is a completely rewritten version of the first part of math.AG/0108078. It also contains several new results