Questions tagged [symmetric-groups]

A symmetric group is a group consisting of all permutations of given finite set, with composition of permutations as the binary operation. Should be used with the (group-theory) tag.

The symmetric group $S_n$ is a group consisting of all permutations of a set of $n$ elements with composition as the binary operation. You could equivalently think of it as the group of all bijective functions from a set $\{1,2,\dotsc,n\}$ to itself. The symmetric group can be generated by the functions that swap adjacent pairs of elements $\{1,2,\dotsc,n\}$. This leads the a common presentation of the symmetric groups with generators $\langle \sigma_1, \sigma_2, \dotsc, \sigma_{n-1}\rangle$ and relations

  • $\sigma_i^2 = 1$
  • $\sigma_i\sigma_j = \sigma_j\sigma_i$ for $|i-j|>1$
  • $(\sigma_i\sigma_{i+1})^3 = 1$
2772 questions
0
votes
1 answer

solution to $X^3=(1,2,3)$

$N>4$. Consider the symmetric group $S(N)$. Does the equation $X^3 = (1,2,3)$ have a solution in $S(N)$? Since $(1,2,3)$ is an even permutation, any solution (if any exist) must also be an even permutation. I also know that if $z$ is a cycle of…
tony
  • 769
0
votes
1 answer

Count all the function f satisfying followings :

For $A=\{1,2,3,4,5,6,7,8,9,10\}$ Define a function $f : A\to A.$ Then 30 times composite of f, that is ; $f\circ f\circ...\circ f(x) = x$ and 30 is the least number for f to become an identity. How many $f : A\to A$ are there ?
0
votes
1 answer

How can we prove that SO(2) is a subgroup of SO(3)

I have a fixed plane that takes the projection of a 3D image and we need to prove that all the rotations, fixing the plane, is a subgroup of SO(3). From basic understanding I know that the rotations, fixing the plane means it is just SO(2) and thus…
0
votes
2 answers

Problem on symmetric group of order $4$

Let $S_4$ denote the group of permutations of $\{1,2,3,4\}$ and let $H$ be a subgroup of $S_4$ of order $6$ Show that there exists an element $i$ in $\{1,2,3,4\}$ which is fixed by each element of $H$. Please give some required hints to approach…
Learnmore
  • 31,062
1 2
3