English

On cyclic groups covers of the projective line

Algebraic Geometry 2025-12-16 v2

Abstract

This article extends the study of cyclic ramified covers of the projective line defined by Kummer equations. We consider the most general case of such covers, allowing arbitrary orders in the roots of the generating radicant. The primary goal is the computation of the fundamental group of both the open and complete curve. We employ tools of combinatorial group theory utilizing the Smith Normal Form. This result is further visualized through the theory of foldings and SS-graphs. Finally, we apply the theory of Alexander modules and the Crowell exact sequence to compute the abelianization of the fundamental group, H1(X,Z)H_{1}(X, \mathbb{Z}), and determine its Galois~module~structure over a field kk confirming the result using the Chevalley-Weil formula.

Keywords

Cite

@article{arxiv.2502.00732,
  title  = {On cyclic groups covers of the projective line},
  author = {George Katsimprakis and Aristides Kontogeorgis},
  journal= {arXiv preprint arXiv:2502.00732},
  year   = {2025}
}

Comments

27 pages, 5 figures

R2 v1 2026-06-28T21:29:26.695Z