English

Nef divisors of surfaces given by pencils at infinity

Algebraic Geometry 2026-02-18 v1

Abstract

We give generators for the nef cone and the cone of curves of rational surfaces obtained by blowing-up the complex projective plane at a set of points BD\mathcal{B} \cup \mathcal{D}, where B\mathcal{B} is the set of (proper and infinitely near) base points of a pencil associated with a curve having one place at infinity, and D\mathcal{D} is a set of finitely many infinitely near free points on the strict transforms of curves of the pencil. We also prove that, when the pencil is given by an AMS-type curve and D\mathcal{D} contains at most two free points on any curve considered, the Cox ring of the obtained surface is finitely generated.

Keywords

Cite

@article{arxiv.2602.15703,
  title  = {Nef divisors of surfaces given by pencils at infinity},
  author = {Carlos Galindo and Francisco Monserrat and Carlos-Jesús Moreno-Ávila and Elvira Pérez-Callejo},
  journal= {arXiv preprint arXiv:2602.15703},
  year   = {2026}
}