Bourbaki

Corollary

Tag 09B8, permanent. Cite it as [Bourbaki, Tag 09B8].

Integration, chapter VI, § 2. Vectorial measures . "

— Let m be a bounded complex measure. Every function f∈LF∞(m)f \in \mathscr{L}_\mathbf{F}^\infty(m) is then m-integrable, and ∣∫f dm∣≤N∞(f)∥m∥\left| \int f \, dm \right| \leq N_\infty(f)\|m\|.

For, ff is mm-measurable and, setting μ=∣m∣\mu = |m|, we have

∫∗∣f∣ dμ≤N∞(f)∥μ∥=N∞(f)∥m∥, \int^* |f| \, d\mu \leq N_\infty(f)\|\mu\| = N_\infty(f)\|m\|,
therefore ff is ∣m∣|m|-integrable (Ch. IV, §5, No. 6, Th. 5) and
∣∫f dm∣≤∫∣f∣ dμ≤N∞(f)∥m∥. \left| \int f \, dm \right| \leq \int |f| \, d\mu \leq N_\infty(f)\|m\|.

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.