The modular automorphisms of quotient modular curves

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Bars, Francesc, Dalal, Tarun
Format: Preprint
Veröffentlicht: 2025
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866916736833421312
author Bars, Francesc
Dalal, Tarun
author_facet Bars, Francesc
Dalal, Tarun
contents We obtain the modular automorphism group of any quotient modular curve of level $N$, with $4,9\nmid N$. In particular, we obtain some non-expected automorphisms of order 3 that appear for the quotient modular curves when the Atkin-Lehner involution $w_{25}$ belongs to the quotient modular group, such automorphisms are not necessarily defined over $\mathbb{Q}$. As a consequence of the results, we obtain the full automorphism group of the quotient modular curve $X_0^*(N^2)$, for sufficiently large $N$.
format Preprint
id arxiv_https___arxiv_org_abs_2505_08401
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle The modular automorphisms of quotient modular curves
Bars, Francesc
Dalal, Tarun
Number Theory
Algebraic Geometry
Group Theory
We obtain the modular automorphism group of any quotient modular curve of level $N$, with $4,9\nmid N$. In particular, we obtain some non-expected automorphisms of order 3 that appear for the quotient modular curves when the Atkin-Lehner involution $w_{25}$ belongs to the quotient modular group, such automorphisms are not necessarily defined over $\mathbb{Q}$. As a consequence of the results, we obtain the full automorphism group of the quotient modular curve $X_0^*(N^2)$, for sufficiently large $N$.
title The modular automorphisms of quotient modular curves
topic Number Theory
Algebraic Geometry
Group Theory
url https://arxiv.org/abs/2505.08401