English

Trigonal and embedded tropical curves of low genus

Algebraic Geometry 2026-02-03 v1 Combinatorics

Abstract

In algebraic geometry, trigonal curves can always be embedded into Hirzebruch surfaces. In tropical geometry, the notion of trigonality does not have a unique translation. We focus on the characterization in terms of the existence of a degree 3 morphism to a line, and discuss relations to possible embeddings into R2\mathbb R^2 reflecting an embedding into a Hirzebruch surface. Our results can be divided into three parts: for tropical curves of low genus 3 and 4, we discuss the relation between a trigonal morphism and an embedding dual to the polygon of a Hirzebruch surface, building on works on embeddings of hyperelliptic tropical curves and curves of low genus. We compare obstructions for embeddings with obstructions for the existence of a degree 3 morphism to a line. Finally, we showcase examples where a non-smooth embedding can be unfolded to reflect certain features of a degree 3 morphism to a line.

Keywords

Cite

@article{arxiv.2602.02257,
  title  = {Trigonal and embedded tropical curves of low genus},
  author = {Hannah Markwig and Angelina Zheng},
  journal= {arXiv preprint arXiv:2602.02257},
  year   = {2026}
}

Comments

32 pages, 44 figures. Comments are welcome!