Frattini and Related Subgroups of Mapping Class Groups
Frattini and Related Subgroups of Mapping Class Groups
Let Γg,b denote the orientation-preserving mapping class group of a closed orientable surface of genus g with b punctures. For a group G let Φf(G) denote the intersection of all maximal subgroups of finite index in G. Motivated by a question of Ivanov as to whether Φf(G) is nilpotent when …