Generalized dihedral groups are ambivalent
From Groupprops
This article gives the statement, and possibly proof, of a particular group or type of group (namely, Generalized dihedral group (?)) satisfying a particular group property (namely, Ambivalent group (?)).
Contents
Statement
Let be any abelian group and
be the generalized dihedral group corresponding to
. Then,
is an ambivalent group: every element of
is conjugate to its inverse. In particular, if
is finite, all characters of
are real-valued.
Related facts
Related facts about generalized dihedral groups
- Generalized dihedral groups are strongly ambivalent
- Classification of rational generalized dihedral groups
Related facts about similar groups
- Dihedral groups are ambivalent
- Dicyclic groups of even degree are ambivalent
- Symmetric groups are rational
- Classification of ambivalent alternating groups
Proof
Proof outline
Any element in the abelian normal subgroup is conjugate to its inverse via the conjugating element. An element outside the abelian normal subgroup is an involution -- it has order two, so it is conjugate to its inverse for obvious reasons.