Subgroup structure of symmetric group:S5: Difference between revisions

From Groupprops
No edit summary
 
(28 intermediate revisions by the same user not shown)
Line 1: Line 1:
The [[symmetric group:S5|symmetric group on five letters]] has many subgroups. We'll take the five letters as <math>\{ 1,2,3,4,5\}</math>.
{{quiz ad}}
{{group-specific information|
information type = subgroup structure|
group = symmetric group:S5|
connective = of}}
 
The [[symmetric group:S5|symmetric group of degree five]] has many subgroups. We'll take the five letters as <math>\{ 1,2,3,4,5\}</math>. The group has order 120.


Note that since <math>S_5</math> is a [[complete group]], every automorphism of it is inner, so the classification of subgroups upto conjugacy is the same as the classification of subgroups upto automorphism. In other words, every subgroup is an [[automorph-conjugate subgroup]].
Note that since <math>S_5</math> is a [[complete group]], every automorphism of it is inner, so the classification of subgroups upto conjugacy is the same as the classification of subgroups upto automorphism. In other words, every subgroup is an [[automorph-conjugate subgroup]].


# The trivial subgroup. Isomorphic to [[subgroup::trivial group]]. (1)
==Tables for quick information==
# The two-element subgroup generated by a transposition, such as <math>(1,2)</math>. Isomorphic to [[cyclic group:Z2|cyclic group of order two]]. (10).
 
# The two-element subgroup generated by a double transposition, such as <math>(1,2)(3,4)</math>. Isomorphic to [[cyclic group:Z2|cyclic group of order two]]. (15)
{{finite group subgroup structure facts to check against}}
# The four-element subgroup spanned by two disjoint transpositions, such as <math>\langle (1,2) , (3,4) \rangle</math>. Isomorphic to [[Klein four-group]]. (15)
<section begin="summary"/>
# The four-element subgroup containing the identity and three double transpositions on a subset of size four. Isomorphic to [[Klein four-group]]. (5)
 
# The four-element subgroup spanned by a 4-cycle. Isomorphic to [[cyclic group:Z4|cyclic group of order four]]. (15)
===Quick summary===
# The eight-element subgroup spanned by a 4-cycle and a transposition that conjugates this cycle to its inverse. Isomorphic to [[dihedral group:D8|dihedral group of order eight]]. (5)
 
# The three-element subgroup spanned by a three-cycle. Isomorphic to [[cyclic group:Z3|cyclic group of order three]]. (10)
{| class="sortable" border="1"
# The six-element spanned by a 3-cycle and a transposition disjoint from it. Isomorphic to [[cyclic group:Z6|cyclic group of order six]]. (10)
! Item !! Value
# The six-element subgroup spanned by all permutations on a subset of size three. Isomorphic to [[symmetric group:S3|symmetric group on three elements]]. (10)
|-
# The six-element subgroup obtained by taking permutations on a particular subset of size three, and multiplying this by a transposition on the remaining two elements if the permutation is odd. Isomorphic to [[symmetric group:S3|symmetric group on three letters]].
| [[Number of subgroups]] || 156<br>Compared with <math>S_n, n = 1,2,3,4,5,6,7,\dots</math>: 1,2,6,30,'''156''',1455,11300, 151221
# The twelve-element subgroup generated by the symmetric group on three letters and the symmetric group on the remaining two letters. (10)
|-
# The twelve-element subgroup obtained as the alternating group on four letters. Isomorphic to [[alternating group:A4|alternating group on four letters]]. (5)
| [[Number of conjugacy classes of subgroups]] || 19<br>Compared with <math>S_n</math>, <math>n = 1,2,3,4,5,6,7,\dots</math>: 1,2,4,11,'''19''',56,96,296,554,1593
# The 24-element subgroup obtained as the symmetric group on four letters. Isomorphic to [[symmetric group:S4|symmetric group on four letters]]. (5)
|-
# The five-element subgroup generated by a five-cycle. Isomorphic to [[cyclic group:Z5|cyclic group on five leters]]. (6)
| [[Number of automorphism classes of subgroups]] || 19<br>Compared with <math>S_n</math>, <math>n = 1,2,3,4,5,6,7,\dots</math>: 1,2,4,11,'''19''',37,96,296,554,1593
# The ten-element subgroup generated by a five-cycle and a double transposition that conjugate it to its inverse. Isomorphic to [[dihedral group:D10|dihedral group of order ten]]. (6)
|-
# The twenty-element subgroup generated by a five-cycle and a four-cycle that conjugates it to its square. (6)
| Isomorphism classes of [[Sylow subgroup]]s and the corresponding [[Sylow number]]s and [[fusion system]]s || 2-Sylow: [[dihedral group:D8]] (order 8), Sylow number is 15, fusion system is [[non-inner non-simple fusion system for dihedral group:D8]]<br>3-Sylow: [[cyclic group:Z3]], Sylow number is 10, fusion system is [[non-inner fusion system for cyclic group:Z3]]<br>5-Sylow: [[Z5 in S5]], Sylow number is 6, fusion system is [[universal fusion system for cyclic group:Z5]]
# The alternating group on all five letters. Isomorphic to [[subgroup::alternating group:A5|alternating group on five letters]]. (1)
|-
# The whole group. (1)
| [[Hall subgroup]]s || <math>\{ 2,3 \}</math>-Hall subgroup: [[S4 in S5]] (order 24)<br>No <math>\{ 2,5 \}</math>-Hall subgroup or <math>\{ 3,5 \}</math>-Hall subgroup
|-
| [[maximal subgroup]]s || maximal subgroups have orders 12 ([[direct product of S3 and S2 in S5]]), 20 ([[GA(1,5) in S5]]), 24 ([[S4 in S5]]), 60 ([[A5 in S5]])
|-
| [[normal subgroup]]s || There are three normal subgroups: the whole group, [[A5 in S5]], and the trivial subgroup.
|}
 
===Table classifying subgroups up to automorphisms===
 
Note that the only normal subgroups are the trivial subgroup, the whole group, and [[A5 in S5]], so we do not waste a column on specifying whether the subgroup is normal and on the quotient group.
 
{{subgroup order sorting note}}
 
{| class="sortable" border="1"
! Automorphism class of subgroups !! Representative subgroup (full list if small, generating set if large) !! Isomorphism class !! [[Order of a group|Order]] of subgroups !! [[Index of a subgroup|Index]] of subgroups !! Number of conjugacy classes (= 1 iff [[automorph-conjugate subgroup]]) !! Size of each conjugacy class (= 1 iff [[normal subgroup]]) !! Total number of subgroups (= 1 iff [[characteristic subgroup]]) !! Note
|-
| trivial subgroup || <math>()</math> || [[trivial group]] || 1 || 120 || 1 || 1 || 1 || trivial
|-
| [[S2 in S5]] || <math>\{ (), (1,2) \}</math> || [[cyclic group:Z2]] || 2 || 60 || 1 || 10 || 10 ||
|-
| [[subgroup generated by double transposition in S5]] || <math>\{ (), (1,2)(3,4) \}</math> || [[cyclic group:Z2]] || 2 || 60 || 1 || 15 || 15 ||
|-
| [[subgroup generated by pair of disjoint transpositions in S5]] || <math>\{ (), (1,2), (3,4), (1,2)(3,4) \}</math> || [[Klein four-group]] || 4 || 30 || 1 || 15 || 15 ||
|-
| [[subgroup generated by double transpositions on four elements in S5]] || <math>\{ (), (1,2)(3,4), (1,3)(2,4), (1,4)(2,3) \}</math> || [[Klein four-group]] || 4 || 30 || 1 || 5 || 5 ||
|-
| [[Z4 in S5]] || <math>\{ (), (1,2,3,4), (1,3)(2,4), (1,4,3,2) \}</math> || [[cyclic group:Z4]] || 4 || 30 || 1 || 15 || 15 ||
|-
| [[D8 in S5]] || <math>\langle (1,2,3,4), (1,3) \rangle</math> || [[dihedral group:D8]] || 8 || 15 || 1 || 15 || 15 || 2-[[Sylow subgroup|Sylow]]
|-
| [[Z3 in S5]] || <math>\{ (), (1,2,3), (1,3,2) \}</math> || [[cyclic group:Z3]] || 3 || 40 || 1 || 10 || 10 || 3-[[Sylow subgroup|Sylow]]
|-
| [[Z6 in S5]] || <math>\langle (1,2,3), (4,5) \rangle</math> || [[cyclic group:Z6]] || 6 || 20 ||1 || 10 || 10 ||
|-
| [[S3 in S5]] || <math>\langle (1,2,3), (1,2) \rangle</math> || [[symmetric group:S3]] || 6 || 20 ||1 || 10 || 10 ||
|-
| [[twisted S3 in S5]] || <math>\langle (1,2,3), (1,2)(4,5) \rangle</math> || [[symmetric group:S3]] || 6 || 20 || 1 || 10 || 10 ||
|-
| [[direct product of S3 and S2 in S5]] || <math>\langle (1,2,3), (1,2), (4,5) \rangle</math> || [[direct product of S3 and Z2]] || 12 || 10 || 1 || 10 || 10 || 3-[[Sylow normalizer]]
|-
| [[A4 in S5]] || <math>\langle (1,2)(3,4), (1,2,3) \rangle</math> || [[alternating group:A4]] || 12 || 10 || 1 || 5 || 5 ||
|-
| [[S4 in S5]] || <math>\langle (1,2,3,4), (1,2) \rangle</math> || [[symmetric group:S4]] || 24 || 5 || 1 || 5 || 5 ||(2,3)-[[Hall subgroup|Hall]]
|-
| [[Z5 in S5]] || <math>\langle (1,2,3,4,5) \rangle</math> || [[cyclic group:Z5]] || 5 || 24 || 1 || 6 || 6 || 5-[[Sylow subgroup|Sylow]]
|-
| [[D10 in S5]] || <math>\langle (1,2,3,4,5), (2,5)(3,4) \rangle</math> || [[dihedral group:D10]] || 10 || 12 || 1 || 6 || 6 ||
|-
| [[GA(1,5) in S5]] || <math>\langle (1,2,3,4,5), (2,3,5,4) \rangle</math> || [[general affine group:GA(1,5)]] || 20 || 6 || 1 || 6 || 6 ||
|-
| [[A5 in S5]] || <math>\langle (1,2,3,4,5), (1,2,3)\rangle</math> || [[alternating group:A5]] || 60 || 2 || 1 || 1 || 1 || only proper nontrivial [[normal subgroup]], quotient is [[cyclic group:Z2]]
|-
| whole group || <math>\langle (1,2,3,4,5), (1,2) \rangle</math> || [[symmetric group:S5]] || 120 || 1 || 1 || 1 || 1 ||
|-
! Total (19 rows) !! -- !! -- !! -- !! -- !! 19 !! -- !! 156 !! --
|}
<section end="summary"/>
 
===Table classifying isomorphism types of subgroups===
 
{| class="sortable" border="1"
! Group name !! Order !! Second part of GAP ID (first part is order) !! Occurrences as subgroup !! Conjugacy classes of occurrence as subgroup !! Automorphism classes of occurrence as subgroup !! Occurrences as normal subgroup !! Occurrences as characteristic subgroup
|-
| [[trivial group]] || 1 || 1 || 1 || 1 || 1 || 1 || 1
|-
| [[cyclic group:Z2]] || 2 || 1 || 25 || 2 || 2 || 0 || 0
|-
| [[cyclic group:Z3]] || 3 || 1 || 10 || 1 || 1 || 0 || 0
|-
| [[cyclic group:Z4]] || 4 || 1 || 15 || 1 || 1 || 0 || 0
|-
| [[Klein four-group]] || 4 || 2 || 20 || 2 || 2 || 0 || 0
|-
| [[cyclic group:Z5]] || 5 || 1 || 6 || 1 || 1 || 0 || 0
|-
| [[symmetric group:S3]] || 6 || 1 || 20 || 2 || 2 || 0 || 0
|-
| [[cyclic group:Z6]] || 6 || 2 || 10 || 1 || 1 || 0 || 0
|-
| [[dihedral group:D8]] || 8 || 3 || 15 || 1 || 1 || 0 || 0
|-
| [[dihedral group:D10]] || 10 || 1 || 6 || 1 || 1 || 0 || 0
|-
| [[alternating group:A4]] || 12 || 3 || 5 || 1 || 1 || 0 || 0
|-
| [[direct product of S3 and Z2]] || 12 || 4 || 10 || 1 || 1 || 0 || 0
|-
| [[general affine group:GA(1,5)]] || 20 || 3 || 6 || 1 || 1 || 0 || 0
|-
| [[symmetric group:S4]] || 24 || 12 || 5 || 1 || 1 || 0 || 0
|-
| [[alternating group:A5]] || 60 || 5 || 1 || 1 || 1 || 1 || 1
|-
| [[symmetric group:S5]] || 120 || 34 || 1 || 1 || 1 || 1 || 1
|-
| Total || -- || -- || 156 || 19 || 19 || 3 || 3
|}
 
===Table listing number of subgroups by order===
 
Note that these orders satisfy the [[congruence condition on number of subgroups of given prime power order]]: the number of subgroups of order <math>p^r</math> is congruent to <math>1</math> modulo <math>p</math>.
 
{| class="sortable" border="1"
! Group order !! Occurrences as subgroup !! Conjugacy classes of occurrence as subgroup !! Automorphism classes of occurrence as subgroup !! Occurrences as normal subgroup !! Occurrences as characteristic subgroup
|-
| 1 || 1 || 1 || 1 || 1 || 1
|-
| 2 || 25 || 2 || 2 || 0 || 0
|-
| 3 || 10 || 1 || 1 || 0 || 0
|-
| 4 || 35 || 3 || 3 || 0 || 0
|-
| 5 || 6 || 1 || 1 || 0 || 0
|-
| 6 || 30 || 3 || 3 || 0 || 0
|-
| 8 || 15 || 1 || 1 || 0 || 0
|-
| 10 || 6 || 1 || 1 || 0 || 0
|-
| 12 || 15 || 2 || 2 || 0 || 0
|-
| 20 || 6 || 1 || 1 || 0 || 0
|-
| 24 || 5 || 1 || 1 || 0 || 0
|-
| 60 || 1 || 1 || 1 || 1 || 1
|-
| 120 || 1 || 1 || 1 || 1 || 1
|-
| Total || 156 || 19 || 19 || 3 || 3
|}

Latest revision as of 06:06, 28 January 2014

TAKE A QUIZ ON THIS TOPIC and test the quality of your understanding of it

This article gives specific information, namely, subgroup structure, about a particular group, namely: symmetric group:S5.
View subgroup structure of particular groups | View other specific information about symmetric group:S5

The symmetric group of degree five has many subgroups. We'll take the five letters as {1,2,3,4,5}. The group has order 120.

Note that since S5 is a complete group, every automorphism of it is inner, so the classification of subgroups upto conjugacy is the same as the classification of subgroups upto automorphism. In other words, every subgroup is an automorph-conjugate subgroup.

Tables for quick information

FACTS TO CHECK AGAINST FOR SUBGROUP STRUCTURE: (finite group)
Lagrange's theorem (order of subgroup times index of subgroup equals order of whole group, so both divide it), |order of quotient group divides order of group (and equals index of corresponding normal subgroup)
Sylow subgroups exist, Sylow implies order-dominating, congruence condition on Sylow numbers|congruence condition on number of subgroups of given prime power order
normal Hall implies permutably complemented, Hall retract implies order-conjugate

Quick summary

Item Value
Number of subgroups 156
Compared with Sn,n=1,2,3,4,5,6,7,…: 1,2,6,30,156,1455,11300, 151221
Number of conjugacy classes of subgroups 19
Compared with Sn, n=1,2,3,4,5,6,7,…: 1,2,4,11,19,56,96,296,554,1593
Number of automorphism classes of subgroups 19
Compared with Sn, n=1,2,3,4,5,6,7,…: 1,2,4,11,19,37,96,296,554,1593
Isomorphism classes of Sylow subgroups and the corresponding Sylow numbers and fusion systems 2-Sylow: dihedral group:D8 (order 8), Sylow number is 15, fusion system is non-inner non-simple fusion system for dihedral group:D8
3-Sylow: cyclic group:Z3, Sylow number is 10, fusion system is non-inner fusion system for cyclic group:Z3
5-Sylow: Z5 in S5, Sylow number is 6, fusion system is universal fusion system for cyclic group:Z5
Hall subgroups {2,3}-Hall subgroup: S4 in S5 (order 24)
No {2,5}-Hall subgroup or {3,5}-Hall subgroup
maximal subgroups maximal subgroups have orders 12 (direct product of S3 and S2 in S5), 20 (GA(1,5) in S5), 24 (S4 in S5), 60 (A5 in S5)
normal subgroups There are three normal subgroups: the whole group, A5 in S5, and the trivial subgroup.

Table classifying subgroups up to automorphisms

Note that the only normal subgroups are the trivial subgroup, the whole group, and A5 in S5, so we do not waste a column on specifying whether the subgroup is normal and on the quotient group.

TABLE SORTING AND INTERPRETATION: Note that the subgroups in the table below are sorted based on the powers of the prime divisors of the order, first covering the smallest prime in ascending order of powers, then powers of the next prime, then products of powers of the first two primes, then the third prime, then products of powers of the first and third, second and third, and all three primes. The rationale is to cluster together subgroups with similar prime powers in their order. The subgroups are not sorted by the magnitude of the order. To sort that way, click the sorting button for the order column. Similarly you can sort by index or by number of subgroups of the automorphism class.

Automorphism class of subgroups Representative subgroup (full list if small, generating set if large) Isomorphism class Order of subgroups Index of subgroups Number of conjugacy classes (= 1 iff automorph-conjugate subgroup) Size of each conjugacy class (= 1 iff normal subgroup) Total number of subgroups (= 1 iff characteristic subgroup) Note
trivial subgroup () trivial group 1 120 1 1 1 trivial
S2 in S5 {(),(1,2)} cyclic group:Z2 2 60 1 10 10
subgroup generated by double transposition in S5 {(),(1,2)(3,4)} cyclic group:Z2 2 60 1 15 15
subgroup generated by pair of disjoint transpositions in S5 {(),(1,2),(3,4),(1,2)(3,4)} Klein four-group 4 30 1 15 15
subgroup generated by double transpositions on four elements in S5 {(),(1,2)(3,4),(1,3)(2,4),(1,4)(2,3)} Klein four-group 4 30 1 5 5
Z4 in S5 {(),(1,2,3,4),(1,3)(2,4),(1,4,3,2)} cyclic group:Z4 4 30 1 15 15
D8 in S5 ⟨(1,2,3,4),(1,3)⟩ dihedral group:D8 8 15 1 15 15 2-Sylow
Z3 in S5 {(),(1,2,3),(1,3,2)} cyclic group:Z3 3 40 1 10 10 3-Sylow
Z6 in S5 ⟨(1,2,3),(4,5)⟩ cyclic group:Z6 6 20 1 10 10
S3 in S5 ⟨(1,2,3),(1,2)⟩ symmetric group:S3 6 20 1 10 10
twisted S3 in S5 ⟨(1,2,3),(1,2)(4,5)⟩ symmetric group:S3 6 20 1 10 10
direct product of S3 and S2 in S5 ⟨(1,2,3),(1,2),(4,5)⟩ direct product of S3 and Z2 12 10 1 10 10 3-Sylow normalizer
A4 in S5 ⟨(1,2)(3,4),(1,2,3)⟩ alternating group:A4 12 10 1 5 5
S4 in S5 ⟨(1,2,3,4),(1,2)⟩ symmetric group:S4 24 5 1 5 5 (2,3)-Hall
Z5 in S5 ⟨(1,2,3,4,5)⟩ cyclic group:Z5 5 24 1 6 6 5-Sylow
D10 in S5 ⟨(1,2,3,4,5),(2,5)(3,4)⟩ dihedral group:D10 10 12 1 6 6
GA(1,5) in S5 ⟨(1,2,3,4,5),(2,3,5,4)⟩ general affine group:GA(1,5) 20 6 1 6 6
A5 in S5 ⟨(1,2,3,4,5),(1,2,3)⟩ alternating group:A5 60 2 1 1 1 only proper nontrivial normal subgroup, quotient is cyclic group:Z2
whole group ⟨(1,2,3,4,5),(1,2)⟩ symmetric group:S5 120 1 1 1 1
Total (19 rows) -- -- -- -- 19 -- 156 --

Table classifying isomorphism types of subgroups

Group name Order Second part of GAP ID (first part is order) Occurrences as subgroup Conjugacy classes of occurrence as subgroup Automorphism classes of occurrence as subgroup Occurrences as normal subgroup Occurrences as characteristic subgroup
trivial group 1 1 1 1 1 1 1
cyclic group:Z2 2 1 25 2 2 0 0
cyclic group:Z3 3 1 10 1 1 0 0
cyclic group:Z4 4 1 15 1 1 0 0
Klein four-group 4 2 20 2 2 0 0
cyclic group:Z5 5 1 6 1 1 0 0
symmetric group:S3 6 1 20 2 2 0 0
cyclic group:Z6 6 2 10 1 1 0 0
dihedral group:D8 8 3 15 1 1 0 0
dihedral group:D10 10 1 6 1 1 0 0
alternating group:A4 12 3 5 1 1 0 0
direct product of S3 and Z2 12 4 10 1 1 0 0
general affine group:GA(1,5) 20 3 6 1 1 0 0
symmetric group:S4 24 12 5 1 1 0 0
alternating group:A5 60 5 1 1 1 1 1
symmetric group:S5 120 34 1 1 1 1 1
Total -- -- 156 19 19 3 3

Table listing number of subgroups by order

Note that these orders satisfy the congruence condition on number of subgroups of given prime power order: the number of subgroups of order pr is congruent to 1 modulo p.

Group order Occurrences as subgroup Conjugacy classes of occurrence as subgroup Automorphism classes of occurrence as subgroup Occurrences as normal subgroup Occurrences as characteristic subgroup
1 1 1 1 1 1
2 25 2 2 0 0
3 10 1 1 0 0
4 35 3 3 0 0
5 6 1 1 0 0
6 30 3 3 0 0
8 15 1 1 0 0
10 6 1 1 0 0
12 15 2 2 0 0
20 6 1 1 0 0
24 5 1 1 0 0
60 1 1 1 1 1
120 1 1 1 1 1
Total 156 19 19 3 3