Properties

Label 16.9.2.b1.a1
Order $ 2^{3} $
Index $ 2 $
Normal Yes

Downloads

Learn more

Subgroup ($H$) information

Description:$C_8$
Order: \(8\)\(\medspace = 2^{3} \)
Index: \(2\)
Exponent: \(8\)\(\medspace = 2^{3} \)
Generators: $b$ Copy content Toggle raw display
Nilpotency class: $1$
Derived length: $1$

The subgroup is characteristic (hence normal), maximal, cyclic (hence abelian, nilpotent, solvable, supersolvable, monomial, elementary, hyperelementary, metacyclic, metabelian, a Z-group, and an A-group), and a $p$-group.

Ambient group ($G$) information

Description: $Q_{16}$
Order: \(16\)\(\medspace = 2^{4} \)
Exponent: \(8\)\(\medspace = 2^{3} \)
Nilpotency class:$3$
Derived length:$2$

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

Quotient group ($Q$) structure

Description: $C_2$
Order: \(2\)
Exponent: \(2\)
Automorphism Group: $C_1$, of order $1$
Outer Automorphisms: $C_1$, of order $1$
Nilpotency class: $1$
Derived length: $1$

The quotient is cyclic (hence abelian, nilpotent, solvable, supersolvable, monomial, elementary, hyperelementary, metacyclic, metabelian, a Z-group, and an A-group), a $p$-group, simple, 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)$$D_8:C_2$, of order \(32\)\(\medspace = 2^{5} \)
$\operatorname{Aut}(H)$ $C_2^2$, of order \(4\)\(\medspace = 2^{2} \)
$\operatorname{res}(\operatorname{Aut}(G))$$C_2^2$, of order \(4\)\(\medspace = 2^{2} \)
$\card{\operatorname{ker}(\operatorname{res})}$\(8\)\(\medspace = 2^{3} \)
$W$$C_2$, of order \(2\)

Related subgroups

Centralizer:$C_8$
Normalizer:$Q_{16}$
Minimal over-subgroups:$Q_{16}$
Maximal under-subgroups:$C_4$

Other information

Möbius function$-1$
Projective image$D_4$