Element structure of symmetric group:S7

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This article gives specific information, namely, element structure, about a particular group, namely: symmetric group:S7.
View element structure of particular groups | View other specific information about symmetric group:S7

This article describes the element structure of symmetric group:S7.

See also element structure of symmetric groups.

For convenience, we take the underlying set to be \{ 1,2,3,4,5,6,7\}.

Conjugacy class structure

FACTS TO CHECK AGAINST FOR CONJUGACY CLASS SIZES AND STRUCTURE:
Divisibility facts: size of conjugacy class divides order of group | size of conjugacy class divides index of center | size of conjugacy class equals index of centralizer
Bounding facts: size of conjugacy class is bounded by order of derived subgroup
Counting facts: number of conjugacy classes equals number of irreducible representations | class equation of a group

Interpretation as symmetric group

FACTS TO CHECK AGAINST SPECIFICALLY FOR SYMMETRIC GROUPS AND ALTERNATING GROUPS:
Please read element structure of symmetric groups for a summary description.
Conjugacy class parametrization: cycle type determines conjugacy class (in symmetric group)
Conjugacy class sizes: conjugacy class size formula in symmetric group
Other facts: even permutation (definition) -- the alternating group is the set of even permutations | splitting criterion for conjugacy classes in the alternating group (from symmetric group)| criterion for element of alternating group to be real

For a symmetric group, cycle type determines conjugacy class, so the conjugacy classes are parametrized by the set of unordered integer partitions of the number 7.


Partition Verbal description of cycle type Representative element Size of conjugacy class [[Formula for size Even or odd? If even, splits? If splits, real in alternating group? Element orders
1 + 1 + 1 + 1 + 1 + 1 + 1 seven fixed points () -- the identity element 1 \frac{7!}{(1)^7(7!)} even; no 1
2 + 1 + 1 + 1 + 1 + 1 transposition, five fixed points (1,2) 21 \frac{7!}{(2)(1)^5(5!)}, also \binom{7}{2} in this case odd 2
3 + 1 + 1 + 1 + 1 one 3-cycle, four fixed points (1,2,3) 70 \frac{7!}{(3)(1)^4(4!)} even; no 3
4 + 1 + 1 + 1 one 4-cycle, three fixed points (1,2,3,4) 210 \frac{7!}{(4)(1)^3(3!)} odd 4
2 + 2 + 1 + 1 + 1 two 2-cycles, three fixed points (1,2)(3,4) 105 \frac{7!}{(2)^2(2!)(1)^3(3!)} even;no 2
5 + 1 + 1 one 5-cycle, two fixed points (1,2,3,4,5) 504 \frac{7!}{(5)(1)^2(2!)} even; no 5
3 + 2 + 1 + 1 one 3-cycle, one 2-cycle, two fixed points (1,2,3)(4,5) 420 \frac{7!}{(3)(2)(1)^2(2!)} odd 6
6 + 1 one 6-cycle, one fixed point (1,2,3,4,5,6) 840 \frac{7!}{(6)(1)} odd 6
4 + 2 + 1 one 4-cycle, one 2-cycle, one fixed point (1,2,3,4)(5,6) 630 \frac{7!}{(4)(2)(1)} even;no 4
2 + 2 + 2 + 1 three 2-cycles, one fixed point (1,2)(3,4)(5,6) 105 \frac{7!}{(2)^3(3!)(1)} odd 2
3 + 3 + 1 two 3-cycles, one fixed point (1,2,3)(4,5,6) 280 \frac{7!}{(3)^2(2!)(1)} even;no 3
3 + 2 + 2 one 3-cycle, two transpositions (1,2,3)(4,5)(6,7) 210 \frac{7!}{(3)(2)^2(2!)} even;no 6
5 + 2 one 5-cycle, one transposition (1,2,3,4,5)(6,7) 504 \frac{7!}{(5)(2)} odd 10
4 + 3 one 4-cycle, one 3-cycle (1,2,3,4)(5,6,7) 420 \frac{7!}{(4)(3)} odd 12
7 one 7-cycle (1,2,3,4,5,6,7) 720 \frac{7!}{7} even;yes;no 7