Reflection subgroups of odd-angled Coxeter groups

Abstract

We give a criterion for a finitely generated odd-angled Coxeter group to have a proper finite index subgroup generated by reflections. The answer is given in terms of the least prime divisors of the exponents of the Coxeter relations.

28 pages, lots of figures; accepted version, to appear in J. Combin. Theory A

References in corpus (5)

• Reflection subgroups of Coxeter groups
• Regular subalgebras of affine Kac-Moody algebras
• Reflection subgroups of Euclidean reflection groups
• Maximal rank root subsystems of hyperbolic root systems
• Hyperbolic subalgebras of hyperbolic Kac-Moody algebras