Properties

Label 8.4.4.a1.a1
Order $ 2 $
Index $ 2^{2} $
Normal Yes

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Subgroup ($H$) information

Description:$C_2$
Order: \(2\)
Index: \(4\)\(\medspace = 2^{2} \)
Exponent: \(2\)
Generators: $b^{2}$ Copy content Toggle raw display
Nilpotency class: $1$
Derived length: $1$

The subgroup is the center (hence characteristic, normal, abelian, central, nilpotent, solvable, supersolvable, monomial, metabelian, and an A-group), the commutator subgroup, the Frattini subgroup, the socle, cyclic (hence elementary, hyperelementary, metacyclic, and a Z-group), stem, a $p$-group, simple, and rational.

Ambient group ($G$) information

Description: $Q_8$
Order: \(8\)\(\medspace = 2^{3} \)
Exponent: \(4\)\(\medspace = 2^{2} \)
Nilpotency class:$2$
Derived length:$2$

The ambient group is nonabelian, a $p$-group (hence nilpotent, solvable, supersolvable, monomial, elementary, and hyperelementary), metacyclic (hence metabelian), and rational.

Quotient group ($Q$) structure

Description: $C_2^2$
Order: \(4\)\(\medspace = 2^{2} \)
Exponent: \(2\)
Automorphism Group: $S_3$, of order \(6\)\(\medspace = 2 \cdot 3 \)
Outer Automorphisms: $S_3$, of order \(6\)\(\medspace = 2 \cdot 3 \)
Nilpotency class: $1$
Derived length: $1$

The quotient is abelian (hence nilpotent, solvable, supersolvable, monomial, metabelian, and an A-group), a $p$-group (hence elementary and hyperelementary), metacyclic, and rational.

Automorphism information

Since the subgroup $H$ is characteristic, the automorphism group $\operatorname{Aut}(G)$ of the ambient group acts on $H$, yielding a homomorphism $\operatorname{res} : \operatorname{Aut}(G) \to \operatorname{Aut}(H)$. The image of $\operatorname{res}$ on the inner automorphism group $\operatorname{Inn}(G)$ is the Weyl group $W = G / Z_G(H)$.

$\operatorname{Aut}(G)$$S_4$, of order \(24\)\(\medspace = 2^{3} \cdot 3 \)
$\operatorname{Aut}(H)$ $C_1$, of order $1$
$\operatorname{res}(\operatorname{Aut}(G))$$C_1$, of order $1$
$\card{\operatorname{ker}(\operatorname{res})}$\(24\)\(\medspace = 2^{3} \cdot 3 \)
$W$$C_1$, of order $1$

Related subgroups

Centralizer:$Q_8$
Normalizer:$Q_8$
Minimal over-subgroups:$C_4$$C_4$$C_4$
Maximal under-subgroups:$C_1$

Other information

Möbius function$2$
Projective image$C_2^2$