Bourbaki

Corollary 1

Tag 03E2, permanent. Cite it as [Bourbaki, Tag 03E2].

Théories spectrales, chapter V, § 4. Représentations des groupes compacts

For every π∈G^\pi \in \widehat{G}, the subrepresentation ϱG(π)\boldsymbol{\varrho }_G(\pi ) is the (π‾⊠π)(\overline{\pi}\boxtimes \pi )-isotypical component of ϱG\boldsymbol{\varrho }_G.

Let F be the (π‾⊠π(\overline{\pi}\boxtimes \pi)-isotypical component of ϱG\boldsymbol{\varrho }_G. The space F contains ϱG(π)\boldsymbol{\varrho }_G(\pi ) (prop. 5). Moreover, for every τ∈G^\tau \in \widehat{G} different from π\pi, the intersection of F and ϱG(τ)\boldsymbol{\varrho }_G(\tau ) is zero (prop. 3 of V, p. 461). It follows that F=ϱG(π)F =\boldsymbol{\varrho }_G(\pi ) by applying the theorem.

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.

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Machine translation of the English, by gpt-5.4, against glossary version 34. Not checked by a person.