Breda d'Azevedo, Antonio

Quadrangle groups inclusions / António Breda d’Azevedo... [et al.]. -- © 2016, The Managing Editors. In this paper we generalise Singerman’s results on triangle group inclusions to the broader class of generalised quadrangle groups, that is, Fuchsian groups with signature of genus 0 and generated by three or four elliptic generators. For any possible inclusion P < Q we also give the number of non-conjugate subgroups of Q isomorphic to P.

In Beiträge zur Algebra und Geometrie. -- Heidelberg : Springer-Verlag, 2017. -- ISSN 0138-4821. -- ISSN 2191-0383. -- Vol. 58, no. 2 (2017), pp. 369-394