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Mathlib.MeasureTheory.Function.ConditionalExpectation.LebesgueBochner

Results about both conditional expectations #

For non-negative real functions, we have two versions of the conditional expectation: condExp and condLExp, built from the Bochner and Lebesgue integrals respectively. In this file, we gather results that involve both versions.

Main statements #

theorem MeasureTheory.toReal_condLExp {𝓧 : Type u_1} (m : MeasurableSpace 𝓧) {m𝓧 : MeasurableSpace 𝓧} {μ : Measure 𝓧} {f : 𝓧ENNReal} (hf_meas : AEMeasurable f μ) (hf : ∫⁻ (x : 𝓧), f x μ ) :
(fun (x : 𝓧) => (μ⁻[f|m] x).toReal) =ᶠ[ae μ] μ[fun (x : 𝓧) => (f x).toReal | m]

The two definitions of the conditional expectation condExp and condLExp (for Bochner and Lebesgue integrals respectively) agree almost everywhere.