| Main Article | Discussion | Related Articles [?] | Bibliography [?] | External Links [?] | Citable Version [?] | | | | | | | | This editable Main Article is under development and subject to a disclaimer. [edit intro] In group theory, the Frattini subgroup is the intersection of all maximal subgroups of a group. Formally, Φ ( G ) = G ∩ ⋂ M M {\displaystyle \Phi (G)=G\cap \bigcap _{M}M\,} where M runs over all maximal subgroups of G. If G has no maximal subgroups then Φ ( G ) = G {\displaystyle \Phi (G)=G} . The Frattini is a subgroup, which is normal and indeed characteristic. ## References[edit] * Marshall Hall jr (1959). The theory of groups. New York: Macmillan, 156.