# Normal subgroups of the symmetric group $S_N$

Is there a list of all normal subgroups for $S_N$?

What is a criteria for a finite group to be a normal subgroup of $S_N$?

Which of them are kernels of irreducible representation? From a partition of $N$, we can construct an irreducible representation, so how does the related subgroup look in terms of the partition?

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It is a standard fact in group theory that when $N\geq 5$, the only normal subgroup is $A_N$, which in turn is simple. For $N\leq 4$, you can just do it by hand. There are is of course exactly two one irreducible representation whose kernel is $A_N$, the trivial and the sign representation.
I'd say there's one irreducible representation whose kernel is $A_N$, and one whose kernel contains $A_N$ (but is $S_N$). – Gerry Myerson Jun 9 '11 at 12:20