Symmetric Group S3
Let $A = \{1, 2, 3\}$The elements of $S_{3}$ are:-
$\{ p_{0} = 𝐼, p_{1} = (12), p_{2} = (13), p_{3} = (23), p_{4} = (123), p_{5} = (132)\}$
ORDERS:
1. The order of each of p₁, p₂, p₃, is 2.
2. The order of each of p₄, p₅, is 3.
INVERSES:
1. The inverse of the elements $p_{0}, p_{1}, p_{2}, p_{3}$ is the element itself.
2. $p_{4}^{-1} = p_{5}, p_{5}^{-1} = p_{4}$.
NON-ABELIAN:
As $p_{1}p_{2}= (132)$ and $p_{2}p_{1} =(123)$
Implies $p_{1}p_{2}\neq p_{2}p_{1}$
Thus, $S_{3}$ is non-abelian group.
NON-CYCLIC:
$S_{3}$ is a non-cyclic group.
CALAY TREE:
The subgroups of $S_{3}$ are of order 1, 2, 3, 6.
SUBGROUPS
Subgroup of order 6:
The
subgroup of order 6 is $S_{3}$ itself.
Subgroup of order 3:
There is
only one subgroup of order 3 in $S_{3}$.
$< (123)>
= < (132)> = \{(1), (123), (132)\}$
Subgroups of order 2:
There are three subgroups of order 2 in $S_{3}$.
1. $<(12)> = \{(1), (12)\}$
2. $<(13)> = \{(1), (13)\}$
3. $<(23)> = \{(1), (23)\}$
Subgroup of order 1:
The subgroup of order one is $\{𝐼\}$.
Commutator Subgroup Of $S_{3}$
$S_{3}=\{(1),(12),(13),(23),(123),(132)\}$
$[(1), (1)] = [(1), (12)] = [(1), (13)] = [(1), (23)] = [(1), (123)] = [(1), (132)] = (1) $
$[(12), (1)] = [(12), (12)] = (1)$
$[(12), (13)] = [(12), (132)] = (123)$
$[(12), (23)] = [(12), (123)] = (132)$
$[(13), (1)] = [(13), (13)] = (1)$
$[(13), (12)] = [(13), (123)] = (132)$
$[(13), (23)] = [(13), (132)] = (123)$
$[(23), (1)] = [(23), (23)] = (1)$
$[(23), (12)] = [(23), (132)] = (123)$
$[(23), (13)] = [(23), (123)] = (132)$
$[(123), (1)] = [(123), (123)] = [(123), (132)] = (1)$
$[(123), (12)] = [(123), (13)] = [(123), (23)] = (123)$
$[(132), (1)] = [(132), (123)] = [(132), (132)] = (1)$
$[(132), (12)] = [(132), (13)] = [(132), (23)] = (132)$
The set of commutators is:-
$X = \{(1), (123), (132)\}$
Since,
$<X>=\{(1),(123),(132)\}=X$
$<X>=\{(1),(123),(132)\}=X$
Thus, X is commutator subgroup of $S_{3}$.
Conjugacy Classes Of $S_{3}$
Here n=3
|
Partitions of 3
|
cycle type
|
Representative of conjugacy class
|
No. of elements in
conjugacy class
|
conjugacy class
|
Even/Odd
|
|
1,1,1
|
$(1)$
|
$(1)(2)(3)$
|
1
|
$\{(1)\}$
|
Even
|
|
1,2
|
$(1,2)$
|
$(1)(23)$
|
3
|
$\{(12),(13)(23)\}$
|
Odd
|
|
3
|
$(3)$
|
$(123)$
|
2
|
$\{(123),(132)\}$
|
Even
|
Normal Subgroups of $S_{3}$
There are three normal subgroups of $S_{3}$:
1. $\{(1)\}$
2. $\{(1),(123),(132)\}$
3. $S_{3}$
Alternating group $A_{3}$
The elements of $A_{3}$ are:-
$\{(1),(123),(132)\}$
Conjugacy classes of $A_{3}$
There are three conjugacy classes of $A_{3}$:-
1. $\{(1)\}$
2. $\{(123)\}$
3. $\{(132)\}$
Normal Subgroups of $A_{3}$
There are two normal subgroups of A3:-
1. $\{(1)\}$
2. $A_{3}$