English

Geometry and arithmetic of geometrically integral regular del Pezzo surfaces

Algebraic Geometry 2025-11-12 v3

Abstract

We classify geometrically integral regular del Pezzo surfaces which are not geometrically normal over imperfect fields of positive characteristic. Based on this classification, we show that a three-dimensional terminal del Pezzo fibration onto a curve over an algebraically closed field always admits a section. Moreover, we prove that the total space is rational if the base curve is rational and the anticanonical degree of a fibre is at least five.

Keywords

Cite

@article{arxiv.2408.11378,
  title  = {Geometry and arithmetic of geometrically integral regular del Pezzo surfaces},
  author = {Fabio Bernasconi and Hiromu Tanaka},
  journal= {arXiv preprint arXiv:2408.11378},
  year   = {2025}
}

Comments

v3: 40 pages, to appear in Algebra & Number Theory