Citation
Ml. Lang et Sp. Tan, Normalizers of the congruence subgroups of the Hecke group G(5) II, P AM MATH S, 128(8), 2000, pp. 2271-2280
Citations number
13
Categorie Soggetti
Mathematics
Journal title
PROCEEDINGS OF THE AMERICAN MATHEMATICAL SOCIETY
ISSN journal
00029939
→ ACNP
Volume
128
Issue
8
Year of publication
2000
Pages
2271 - 2280
Database
ISI
SICI code
0002-9939(2000)128:8<2271:NOTCSO>2.0.ZU;2-Q
Abstract
Let lambda = 2cos(pi/5). Let (tau) bean ideal of Z[lambda] and let (tau(o))
be the maximal ideal of Z [lambda] such that (tau(o)(2)) subset of or equa
l to (tau). Then N(G(o)(tau)) less than or equal to G(o)(tau(o)). In partic
ular, if tau is square free, then G(o)(tau) is self-normalized in PSL2(R).