English

The integral Picard groups of low-degree Hurwitz spaces

Algebraic Geometry 2021-10-29 v1

Abstract

We compute the Picard groups with integral coefficients of the Hurwitz stacks parametrizing degree 44 and 55 covers of P1\mathbb{P}^1. As a consequence, we also determine the integral Picard groups of the Hurwitz stacks parametrizing simply branched covers. For simple branching, the Picard groups are finite, with order depending on the genus.

Keywords

Cite

@article{arxiv.2110.14727,
  title  = {The integral Picard groups of low-degree Hurwitz spaces},
  author = {Samir Canning and Hannah Larson},
  journal= {arXiv preprint arXiv:2110.14727},
  year   = {2021}
}

Comments

21 pages, split off from arXiv:2103.09902v1 because of length, added Corollary 1.3