Bourbaki

Corollary 2

Tag 08TA, permanent. Cite it as [Bourbaki, Tag 08TA].

Integration, chapter IV, § 4. Integrable functions and sets

— Every measure with compact support (resp. every positive measure with compact support) μ\mu is in the closure in C′(X;C)\mathscr{C}'(X; \mathbf{C}), for the topology T\mathscr{T} of compact convergence, of the set of measures (resp.

(*) In fact, the mapping x↦εxx \mapsto \varepsilon_x is a homeomorphism of X into C′(X;C)\mathscr{C}'(X; \mathbf{C}) (Ch. VI, §1, No. 6, Remark 1).

positive measures) whose support is finite and contained in Supp(\mu) and whose norm is equal to ∥μ∥\| \mu \|.

For, on the set B of measures ν\nu such that Supp(ν)⊂Supp(μ)\mathrm{Supp}(\nu) \subset \mathrm{Supp}(\mu) and ∥ν∥≤∥μ∥\| \nu \| \leq \| \mu \|, the topology induced by the vague topology is identical to the topology induced by T\mathscr{T}, and the corollary therefore follows from Ch. III, §2, No. 4, Cors. 2 and 3 of Th. 1.

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

Cited by

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Cites

Transcribed from the printed volume. Not translated.