Torsion-free genus zero congruence subgroups of PSL2(R)

Authors
Sebbar, A
Citation
A. Sebbar, Torsion-free genus zero congruence subgroups of PSL2(R), DUKE MATH J, 110(2), 2001, pp. 377-396
Citations number
14
Categorie Soggetti
Mathematics
Journal title
DUKE MATHEMATICAL JOURNAL
ISSN journal
00127094 → ACNP
Volume
110
Issue
2
Year of publication
2001
Pages
377 - 396
Database
ISI
SICI code
0012-7094(20011101)110:2<377:TGZCSO>2.0.ZU;2-X
Abstract
We study and classify all the conjugacy classes, of the genus zero congruen ce subgroups of PSL2(R) with no elliptic elements. We show that it suffices to classify those inside the modular group and determine them completely. We also discuss an application to modular curves.