Bourbaki

Proposition 60

Tag 0ACA, permanent. Cite it as [Bourbaki, Tag 0ACA].

Lie Groups and Lie Algebras, chapter III, § 3. Passage from a Lie group to its Lie algebra

Let GG be a Lie group, of finite dimension if KK is of characteristic > 0, MM a manifold of class CrC^r, ff a mapping of class CrC^r of MM into GG and α\alpha the left differential of ff. Then dα+[α]2=0d\alpha + [\alpha]^2 = 0.

Let ω\omega be the canonical left differential form of GG. Using Corollary 1 to Proposition 51, no. 14, we have

dα=d(f∗(ω))=f∗(dω)=f∗(−[ω]2)=−[f∗(ω)]2=−[α]2. d\alpha = d(f^*(\omega)) = f^*(d\omega) = f^*(-[\omega]^2) = -[f^*(\omega)]^2 = -[\alpha]^2.

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

Cited by

Nothing.

Cites

Transcribed from the printed volume. Not translated.