3. Let S3 act on the set A={(i,j) : 1≤i,j≤3} by σ((i, j)) = (σ(i), σ(j))....

3. Let S3 act on the set A={(i,j) : 1≤i,j≤3} by σ((i, j)) = (σ(i), σ(j)).

(a) Describe the orbits of this action.

(b) Show this is a faithful action, i.e. that the permutation represen- tation φ:S3 →SA =S9

Solutions

Expert Solution

The solution to (a) is obtained by observing that the orbits of any group action partition the set(on which the group acts).

For (b), it suffices to prove that the kernel of the permutation representation is trivial. The proof is not difficult.

For (c), the solution at first enumerates the set A by {1,2,...9}. Then, the action of every group element on A is analysed and finally, the corresponding cycle decompositions of the induced permutations are obtained.

Colby Messinger answered 1 year ago

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