Bourbaki

Example

Tag 05BF, permanent. Cite it as [Bourbaki, Tag 05BF].

Algebra, chapter I, § 5. Groups operating on a set

If E is a G-set, each orbit of E, with the induced operation, is a homogeneous set under G.

Let G be a group and H a subgroup of G. Consider the set G/HG/H of left cosets modulo H. The group G operates on G/HG/H on the left by (g,xH)↦gxH(g, xH) \mapsto gxH. Let N be the normalizer of H. The group N operates on G/HG/H on the right by (xH,n)↦xHn=xnH(xH, n) \mapsto xHn = xnH. This operation induces on H the trivial operation and hence, on passing to the quotient, N/HN/H operates on G/HG/H on the right. Let ϕ:(N/H)0→SG/H\phi : (N/H)^0 \to S_{G/H} be the homomorphism corresponding to this operation.

Bourbaki puts the proof directly after the statement, so what is above is the statement and its proof together.

Cited by

Nothing.

Cites

Nothing.

Transcribed from the printed edition, 1998, Springer. Not translated.