A cluster criterion for potential degeneracy of superelliptic curves
Algebraic Geometry
2025-08-25 v1 Number Theory
Abstract
Let be a field with a discrete valuation; let be a prime; and let be the curve defined by an equation of the form . We show that the curve has a model over an algebraic extension of whose special fiber consists of genus- components and has at worst nodal singularities if and only if the cluster data of the roots of satisfies a certain criterion, and when these hold, we show explicitly how to build the minimal regular model of . We develop an interpretation of cluster data in terms of a convex hull in the Berkovich projective line and express the above results directly in terms of this convex hull.
Keywords
Cite
@article{arxiv.2508.15974,
title = {A cluster criterion for potential degeneracy of superelliptic curves},
author = {Jeffrey Yelton},
journal= {arXiv preprint arXiv:2508.15974},
year = {2025}
}
Comments
48 pages; 7 sections with an appendix; 5 figures; feedback welcome!