Documentation

BrownianMotion.Auxiliary.MeasureTheory

Measure theory lemmas to be upstreamed to Mathlib #

theorem integrable_inner {Ω : Type u_1} {E : Type u_2} {mΩ : MeasurableSpace Ω} {P : MeasureTheory.Measure Ω} {f g : Ω → E} [NormedAddCommGroup E] [InnerProductSpace ℝ E] (hf : MeasureTheory.MemLp f 2 P) (hg : MeasureTheory.MemLp g 2 P) :
MeasureTheory.Integrable (fun (ω : Ω) => inner ℝ (f ω) (g ω)) P
theorem condExp_inner_of_aestronglyMeasurable_left {Ω : Type u_1} {E : Type u_2} {m mΩ : MeasurableSpace Ω} {P : MeasureTheory.Measure Ω} {f g : Ω → E} [NormedAddCommGroup E] [InnerProductSpace ℝ E] [CompleteSpace E] (hf : MeasureTheory.AEStronglyMeasurable f P) (hfg : MeasureTheory.Integrable (fun (ω : Ω) => inner ℝ (f ω) (g ω)) P) (hg : MeasureTheory.Integrable g P) :
P[fun (ω : Ω) => inner ℝ (f ω) (g ω) | m] =ᵐ[P] fun (ω : Ω) => inner ℝ (f ω) (P[g | m] ω)
theorem condExp_inner_of_aestronglyMeasurable_right {Ω : Type u_1} {E : Type u_2} {m mΩ : MeasurableSpace Ω} {P : MeasureTheory.Measure Ω} {f g : Ω → E} [NormedAddCommGroup E] [InnerProductSpace ℝ E] [CompleteSpace E] (hg : MeasureTheory.AEStronglyMeasurable g P) (hfg : MeasureTheory.Integrable (fun (ω : Ω) => inner ℝ (f ω) (g ω)) P) (hf : MeasureTheory.Integrable f P) :
P[fun (ω : Ω) => inner ℝ (f ω) (g ω) | m] =ᵐ[P] fun (ω : Ω) => inner ℝ (P[f | m] ω) (g ω)
theorem Filter.EventuallyEq.div' {α : Type u_1} {β : Type u_2} [Div β] {f f' g g' : α → β} {l : Filter α} (h : f =ᶠ[l] g) (h' : f' =ᶠ[l] g') :
f / f' =ᶠ[l] g / g'
theorem Filter.EventuallyEq.sub' {α : Type u_1} {β : Type u_2} [Sub β] {f f' g g' : α → β} {l : Filter α} (h : f =ᶠ[l] g) (h' : f' =ᶠ[l] g') :
f - f' =ᶠ[l] g - g'
theorem ProbabilityTheory.centralMoment_of_integral_id_eq_zero {Ω : Type u_1} {mΩ : MeasurableSpace Ω} {μ : MeasureTheory.Measure Ω} {X : Ω → ℝ} (p : ℕ) (hX : ∫ (x : Ω), X x ∂μ = 0) :
centralMoment X p μ = ∫ (ω : Ω), X ω ^ p ∂μ
@[simp]
theorem zero_mem_parallelepiped {ι : Type u_1} {E : Type u_2} [Fintype ι] [AddCommGroup E] [Module ℝ E] {v : ι → E} :
@[simp]
theorem nonempty_parallelepiped {ι : Type u_1} {E : Type u_2} [Fintype ι] [AddCommGroup E] [Module ℝ E] {v : ι → E} :

The measure of a closed ball for a left-invariant measure does not depend on its center.

The measure of a closed ball of radius r for an additive Haar measure in dimension d is r ^ d times the measure of the unit ball.

For an additive Haar measure in dimension d, the ratio of the measures of two closed balls of radii r and s is (r / s) ^ d.

theorem ProbabilityTheory.covariance_fun_add_left {Ω : Type u_1} {mΩ : MeasurableSpace Ω} {μ : MeasureTheory.Measure Ω} {X Y Z : Ω → ℝ} [MeasureTheory.IsFiniteMeasure μ] (hX : MeasureTheory.MemLp X 2 μ) (hY : MeasureTheory.MemLp Y 2 μ) (hZ : MeasureTheory.MemLp Z 2 μ) :
covariance (fun (ω : Ω) => X ω + Y ω) Z μ = covariance (fun (ω : Ω) => X ω) Z μ + covariance (fun (ω : Ω) => Y ω) Z μ
theorem ProbabilityTheory.covariance_fun_add_right {Ω : Type u_1} {mΩ : MeasurableSpace Ω} {μ : MeasureTheory.Measure Ω} {X Y Z : Ω → ℝ} [MeasureTheory.IsFiniteMeasure μ] (hX : MeasureTheory.MemLp X 2 μ) (hY : MeasureTheory.MemLp Y 2 μ) (hZ : MeasureTheory.MemLp Z 2 μ) :
covariance X (fun (ω : Ω) => Y ω + Z ω) μ = covariance X (fun (ω : Ω) => Y ω) μ + covariance X (fun (ω : Ω) => Z ω) μ
theorem ProbabilityTheory.variance_fun_div {Ω : Type u_1} {mΩ : MeasurableSpace Ω} {μ : MeasureTheory.Measure Ω} {X : Ω → ℝ} (c : ℝ) (hX : AEMeasurable X μ) :
variance (fun (ω : Ω) => X ω / c) μ = variance X μ / c ^ 2
theorem MeasurableSpace.comap_process {Ω : Type u_1} {T : Type u_2} {𝓧 : T → Type u_3} [(t : T) → MeasurableSpace (𝓧 t)] (X : (t : T) → Ω → 𝓧 t) :
MeasurableSpace.comap (fun (ω : Ω) (t : T) => X t ω) pi = ⨆ (t : T), MeasurableSpace.comap (X t) inferInstance
theorem ProbabilityTheory.singleton_indepSets_comap_iff {Ω : Type u_1} {mΩ : MeasurableSpace Ω} {P : MeasureTheory.Measure Ω} [MeasureTheory.IsZeroOrProbabilityMeasure P] {𝓧 : Type u_2} {m𝓧 : MeasurableSpace 𝓧} {A : Set Ω} {X : Ω → 𝓧} (hX : Measurable X) (hA : MeasurableSet A) :
theorem IndepSets.setIntegral_eq_mul {Ω : Type u_1} {𝓧 : Type u_2} {mΩ : MeasurableSpace Ω} {μ : MeasureTheory.Measure Ω} {m𝓧 : MeasurableSpace 𝓧} {X : Ω → 𝓧} [MeasureTheory.IsZeroOrProbabilityMeasure μ] {f : 𝓧 → ℝ} {A : Set Ω} (hA1 : ProbabilityTheory.IndepSets {A} {s : Set Ω | MeasurableSet s} μ) (hX : Measurable X) (hA2 : MeasurableSet A) (hf : MeasureTheory.AEStronglyMeasurable f (MeasureTheory.Measure.map X μ)) :
∫ (ω : Ω) in A, f (X ω) ∂μ = μ.real A * ∫ (ω : Ω), f (X ω) ∂μ
theorem measurableSpace_le_iff {Ω : Type u_1} {m1 m2 : MeasurableSpace Ω} :
m1 ≤ m2 ↔ ∀ (s : Set Ω), MeasurableSet s → MeasurableSet s