Bourbaki

Proposition 5

Tag 09IR, permanent. Cite it as [Bourbaki, Tag 09IR].

Integration, VIII, p. 12, § 2. Linear representations of groups

Suppose that each function χ(s,⋅)\chi(s, \cdot) is bounded. Then γχ\gamma_\chi leaves K(X)‾\overline{K(X)} stable, and the linear representation γχ\gamma_\chi of G in K(X)‾\overline{K(X)} is continuous.

It is clear that γχ\gamma_\chi leaves K(X)‾\overline{K(X)} stable and that each of the γχ(s)\gamma_\chi(s) is continuous in K(X)‾\overline{K(X)}. On the other hand, for every f∈K(X)f \in K(X), s↦γχ(s)fs \mapsto \gamma_\chi(s)f is a continuous mapping of G into K(X)K(X) and a fortiori into K(X)‾\overline{K(X)}. Therefore the representation γχ\gamma_\chi in K(X)‾\overline{K(X)} is continuous (No. 1, Prop. 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.