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ZixuanZhang
ZixuanZhang
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Conjugacy in the Symmetric Group

Two permutations in are conjugate if and only if they have the same cycle type.

Theorem 8.20 (Conjugacy in )
Two permutations are conjugate iff they have the same cycle type.

Proof

Write as disjoint cycles . If has the same cycle type, write its corresponding cycles as and define . Then .

Conversely, if , replacing each by gives a disjoint-cycle expression for with the same cycle lengths as .

Examples

In , the conjugacy classes have representatives and sizes

Their sizes sum to .

Related

Stated in