Finite subgroups of the extended modular group
Group Theory
2022-02-25 v3
Abstract
We show that in the extended modular group PGL(2,Z) there are exactly seven finite subgroups up to conjugacy; three subgroups of size 2, one subgroup each of size 3, 4, and 6, and the trivial subgroup of size 1.
Cite
@article{arxiv.1802.02000,
title = {Finite subgroups of the extended modular group},
author = {Gregory Dresden and Prakriti Panthi and Anukriti Shrestha and Jiahao Zhang},
journal= {arXiv preprint arXiv:1802.02000},
year = {2022}
}
Comments
4 pages; version 2 has a new introduction, a minor change to the statement of Proposition 1, and improved proofs of Proposition 1 and Theorems 2 and 3. Version 3 has updated bibliography and modified introduction