Semistable types of hyperelliptic curves
Abstract
In this paper, we explore three combinatorial descriptions of semistable types of hyperelliptic curves over local fields: dual graphs, their quotient trees by the hyperelliptic involution, and configurations of the roots of the defining equation (`cluster pictures'). We construct explicit combinatorial one-to-one correspondences between the three, which furthermore respect automorphisms and allow to keep track of the monodromy pairing and the Tamagawa group of the Jacobian. We introduce a classification scheme and a naming convention for semistable types of hyperelliptic curves and types with a Frobenius action. This is the higher genus analogue of the distinction between good, split and non-split multiplicative reduction for elliptic curves. Our motivation is to understand -factors, Galois representations, conductors, Tamagawa numbers and other local invariants of hyperelliptic curves and their Jacobians.
Cite
@article{arxiv.1704.08338,
title = {Semistable types of hyperelliptic curves},
author = {Tim Dokchitser and Vladimir Dokchitser and Celine Maistret and Adam Morgan},
journal= {arXiv preprint arXiv:1704.08338},
year = {2026}
}