symmetric group as a subgroup of general linear group

517 Views Asked by At

Is the symmetric group $S_n$ a normal subgroup of the general linear group $GL(n,\mathbb{R})$? We regard $\sigma\in S_n$ acts on $\mathbb{R}^n$ by permuting the coordinates $\sigma(x_1,\cdots,x_n)=(x_{\sigma(1)},\cdots,x_{\sigma(n)})$.

1

There are 1 best solutions below

0
On BEST ANSWER

No, $$\pmatrix{1 &1 \\ 0 &1}\pmatrix{0 &1 \\ 1 &0}\pmatrix{1 &1 \\ 0 &1}^{-1} = \pmatrix{1 &0 \\ 1 &-1}$$ is not a permutation matrix.