Bourbaki

Corollary 1

Tag 01FF, permanent. Cite it as [Bourbaki, Tag 01FF].

Lie Groups and Lie Algebras, chapter IX, § 6. Integration on compact Lie groups

Let F be a Banach space, ρ:H→GL(F)\rho : H\rightarrow \mathbf{G}\mathbf{L}(F) an analytic linear representation, f∈Cr(X;F)f\in \mathscr{C}^r(X; F). For x∈Xx\in X, put

f♯(x)=∫Hρ(h).f(h−1x)dh f^{\sharp}(x) =\int_H\rho (h).f(h^{-1}x)dh

Then f♯f^{\sharp} is a morphism of class CrC^r from X to F, compatible with the operations of H; for x∈Xx\in X, we have (with τh\tau_h denoting the automorphism x→hxx \rightarrow hx of X)

dxf♯=∫H(ρ(h)∘dh−1xf∘Tx(τh−1))dh∈L(Tx(X);F)(14) d_xf^{\sharp}=\int_H(\rho (h)\circ d_{h^{-1}x}f\circ T_x(\tau_{h^{-1}}))dh\in \mathscr{L}(T_x(X); F) \tag{14}

The first assertion follows from the proposition applied to the bundle X×X\times F, equipped with the law of operation (h;(x,f))→(hx,ρ(h).f)(h; (x, f)) \rightarrow (hx, \rho (h).f). The second follows from Integration, Chap. III, §3, no. 2, Prop. 2, by applying to the vector integral f♯f^{\sharp} the homomorphism dx:Cr(X;F)→L(Tx(X);F)d_x:\mathscr{C}^r(X; F)\rightarrow \mathscr{L}(T_x(X); F) which is continuous by the definition of the topology of compact CrC^r-convergence.

Bourbaki sets the proof directly after the statement, and the corpus does not separate them, so what is above is the statement and its proof together.

Cited by

Cites

  • Integration, Chap. III, §3, no. 2, Prop. 2 not in this corpus: INT III
Transcribed from the printed volume. Not translated.