CONSTRUCTION OF CYCLOIDAL FREE SUBGROUPS OF HECKE GROUPS OF FINITE INDEX

Yurttas A., DEMİRCİ M., Ozbay H., Capkin M., CANGÜL İ. N.

JP JOURNAL OF ALGEBRA NUMBER THEORY AND APPLICATIONS, vol.14, no.2, pp.191-201, 2009 (ESCI) identifier

  • Publication Type: Article / Article
  • Volume: 14 Issue: 2
  • Publication Date: 2009
  • Journal Name: JP JOURNAL OF ALGEBRA NUMBER THEORY AND APPLICATIONS
  • Journal Indexes: Emerging Sources Citation Index (ESCI), zbMATH
  • Page Numbers: pp.191-201
  • Bursa Uludag University Affiliated: Yes

Abstract

Cycloidal subgroups of the modular group are studied in [7]. Cycloidal normal subgroups of the Hecke groups, which are generalisations of the modular group, are studied in [2]. Here we study cycloidal free subgroups of Hecke groups. These are subgroups with signature (g; infinity). Here these subgroups are given by their signatures for q = 4, 5, 6 first, and then for all q. It is found that when q equivalent to 2 mod 4, H(lambda(q)) has no cycloidal free subgroups.