# Group actions of subgroup of S_3 onto S_3

1. Sep 29, 2009

### cmj1988

Given a subgroup of G=S3={(1)(2)(3), (1 2)(3)} acting on the set S3 defined as g in G such that gxg-1 for every x in S3. Describe the orbit.

The first one is (1)(2)(3)x(3)(2)(1). This orbit is just the identity.

For the second one, I'm not sure how to describe (1 2)(3) except by multiplying it out.

(1 2)(3)(1)(2)(3)(2 1)(3) = (1)(2)(3)
(1 2)(3)(1 2)(2 1)(3) = (1 2)(3)
(1 2)(3)(1 3)(2 1)(3) = (1)(3 2)
(1 2)(3)(2 3)(2 1)(3) = (1 3)(2)
(1 2)(3)(1 2 3)(2 1)(3) = ?
(1 2)(3)(1 3 2)(2 1)(3) = ?

2. Sep 29, 2009

### aPhilosopher

First four look good.

(1 2)(3)(1 2 3)(2 1)(3) = ?
(1 2)(3)(1 3 2)(2 1)(3) = ?

What's the problem? You know how to compose conjugations. These two are exactly like the ones you were able to get.

3. Sep 29, 2009

### Dick

Aside from permutation issues, I don't think you are using the word 'orbit' correctly. If you write your subgroup as G={e,g} (e=identity, g=(12)) then the orbit of an element a of S3 is {eae^(-1),gag^(-1)}. That's a subset of S3 with either one or two elements. That subset is the orbit of a. Once you finish your table you should be able to split S3 into orbits.

Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook