Center of ambivalent group is elementary abelian 2-group

From Groupprops

Statement

Suppose is an ambivalent group. Then, the center of is an Elementary abelian 2-group (?).

Related facts

Facts used

  1. Conjugacy-closed subgroup of ambivalent group is ambivalent: A conjugacy-closed subgroup is a subgroup with the property that any two elements of the subgroup that are conjugate in the whole group are conjugate in the subgroup.
  2. Abelian and ambivalent iff elementary abelian 2-group

Proof

Direct proof

Given: An ambivalent group with center .

To prove: For any element , (this suffices because the group is already abelian on account of being the center).

Proof: By the definition of ambivalence, we know that and are conjugate in . However, , so this forces that equals all its conjugates, forcing .

Fancy proof

The proof follows directly from facts (1) and (2), and the fact that the center of a group is a conjugacy-closed subgroup.