English

Spaces of sections of quadric surface fibrations over curves

Algebraic Geometry 2011-11-07 v1

Abstract

We consider quadric surface fibrations over curves, defined over algebraically closed and finite fields. Our goal is to understand, in geometric terms, spaces of sections for such fibrations. We analyze varieties of maximal isotropic subspaces in the fibers as P^1-bundles over the discriminant double cover. When the P^1-bundle is suitably stable, we deduce effective estimates for the heights of sections over finite fields satisfying various approximation conditions. We also discuss the behavior of the spaces of sections as the base of the fibration acquires singularities.

Keywords

Cite

@article{arxiv.1111.1203,
  title  = {Spaces of sections of quadric surface fibrations over curves},
  author = {Brendan Hassett and Yuri Tschinkel},
  journal= {arXiv preprint arXiv:1111.1203},
  year   = {2011}
}

Comments

23 pages; to appear in the proceedings of the 2010 conference 'Compact Moduli and Vector Bundles', held at the University of Georgia