Frattini subgroup: Difference between revisions

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:<math>\Phi(G) = G \cap \bigcap_M M  \,</math>
:<math>\Phi(G) = G \cap \bigcap_M M  \,</math>


where ''M'' runs over all maximal subgroups of G.  If ''G'' has no maximal subgroups then <math>\Phi(G) = G</math>.
where ''M'' runs over all [[maximal subgroup]]s of G.  If ''G'' has no maximal subgroups then <math>\Phi(G) = G</math>.


The Frattini is a [[subgroup]], which is [[normal subgroup|normal]] and indeed [[characteristic subgroup|characteristic]].   
The Frattini is a [[subgroup]], which is [[normal subgroup|normal]] and indeed [[characteristic subgroup|characteristic]].   

Revision as of 17:53, 14 November 2008

In group theory, the Frattini subgroup is the intersection of all maximal subgroups of a group.

Formally,

where M runs over all maximal subgroups of G. If G has no maximal subgroups then .

The Frattini is a subgroup, which is normal and indeed characteristic.

References

  • Marshall Hall jr (1959). The theory of groups. New York: Macmillan, 156.