English

On del Pezzo fibrations in positive characteristic

Algebraic Geometry 2023-06-22 v3

Abstract

We establish two results on three-dimensional del Pezzo fibrations in positive characteristic. First, we give an explicit bound for torsion index of relatively torsion line bundles. Second, we show the existence of purely inseparable sections with explicit bounded degree. To prove these results, we study log del Pezzo surfaces defined over imperfect fields.

Keywords

Cite

@article{arxiv.1903.10116,
  title  = {On del Pezzo fibrations in positive characteristic},
  author = {Fabio Bernasconi and Hiromu Tanaka},
  journal= {arXiv preprint arXiv:1903.10116},
  year   = {2023}
}

Comments

50 pages, v2: minor revisions, v3: minor revisions