5. Quotient Groups Flashcards
1
Q
Normal Subgroup
A
A subgroup where it is normal under conjugation: xHx^-1=H or xH=Hx
2
Q
Normaliser
A
The set of elements that satisfy the condition of being normal under conjugation
3
Q
Subgroup of index 2
A
Example of a NORMAL subgroup!
4
Q
Quotient Group
A
Suppose H is a normal subgroup of a group G. Then the Quotient group is the set G/H of left cosets of H.
5
Q
Quotient Map from G to G/H
A
Let H be a normal subgroup of a group G. The group homomorphism sending g∈G to its coset gH
6
Q
Order of Quotient Group
A
|G|/|H|