Finite normal implies potentially characteristic

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Statement

Suppose G is a group and H is a finite normal subgroup of G: H is a normal subgroup of G that is finite as a group. Then, there exists a group K containing G such that H is characteristic in K.

Related facts

Stronger facts

  • Finite NPC theorem: This states that a normal subgroup of a finite group can be realized as a characteristic subgroup in some finite group containing it.
  • NPC theorem: This states that any normal subgroup is potentially characteristic.

Facts used

  1. Finite normal implies amalgam-characteristic
  2. Amalgam-characteristic implies potentially characteristic

Proof

The proof follows directly by piecing together facts (1) and (2).