Documentation

Mathlib.MeasureTheory.Function.LpSeminorm.CompareExp

Compare Lp seminorms for different values of p #

In this file we compare MeasureTheory.eLpNorm' and MeasureTheory.eLpNorm for different exponents.

theorem MeasureTheory.eLpNorm'_le_eLpNorm'_mul_rpow_measure_univ {α : Type u_1} {ε : Type u_2} {m : MeasurableSpace α} {μ : Measure α} {f : α → ε} [TopologicalSpace ε] [ContinuousENorm ε] {p q : ℝ} (hp0_lt : 0 < p) (hpq : p ≤ q) (hf : AEStronglyMeasurable f μ) :
eLpNorm' f p μ ≤ eLpNorm' f q μ * μ Set.univ ^ (1 / p - 1 / q)
theorem MeasureTheory.eLpNorm'_le_eLpNormEssSup_mul_rpow_measure_univ {α : Type u_1} {ε : Type u_2} {m : MeasurableSpace α} {μ : Measure α} {f : α → ε} [TopologicalSpace ε] [ContinuousENorm ε] {q : ℝ} (hq_pos : 0 < q) :
eLpNorm' f q μ ≤ eLpNormEssSup f μ * μ Set.univ ^ (1 / q)
theorem MeasureTheory.eLpNorm_le_eLpNorm_mul_rpow_measure_univ {α : Type u_1} {ε : Type u_2} {m : MeasurableSpace α} {μ : Measure α} {f : α → ε} [TopologicalSpace ε] [ContinuousENorm ε] {p q : ENNReal} (hpq : p ≤ q) (hf : AEStronglyMeasurable f μ) :
eLpNorm f p μ ≤ eLpNorm f q μ * μ Set.univ ^ (1 / p.toReal - 1 / q.toReal)
theorem MeasureTheory.eLpNorm'_le_eLpNorm'_of_exponent_le {α : Type u_1} {ε : Type u_2} {m : MeasurableSpace α} {f : α → ε} [TopologicalSpace ε] [ContinuousENorm ε] {p q : ℝ} (hp0_lt : 0 < p) (hpq : p ≤ q) (μ : Measure α) [IsProbabilityMeasure μ] (hf : AEStronglyMeasurable f μ) :
eLpNorm' f p μ ≤ eLpNorm' f q μ
theorem MeasureTheory.eLpNorm'_le_eLpNormEssSup {α : Type u_1} {ε : Type u_2} {m : MeasurableSpace α} {μ : Measure α} {f : α → ε} [TopologicalSpace ε] [ContinuousENorm ε] {q : ℝ} (hq_pos : 0 < q) [IsProbabilityMeasure μ] :
theorem MeasureTheory.eLpNorm_le_eLpNorm_of_exponent_le {α : Type u_1} {ε : Type u_2} {m : MeasurableSpace α} {μ : Measure α} {f : α → ε} [TopologicalSpace ε] [ContinuousENorm ε] {p q : ENNReal} (hpq : p ≤ q) [IsProbabilityMeasure μ] (hf : AEStronglyMeasurable f μ) :
eLpNorm f p μ ≤ eLpNorm f q μ
theorem MeasureTheory.eLpNorm'_lt_top_of_eLpNorm'_lt_top_of_exponent_le {α : Type u_1} {ε : Type u_2} {m : MeasurableSpace α} {μ : Measure α} {f : α → ε} [TopologicalSpace ε] [ContinuousENorm ε] {p q : ℝ} [IsFiniteMeasure μ] (hf : AEStronglyMeasurable f μ) (hfq_lt_top : eLpNorm' f q μ < ⊤) (hp_nonneg : 0 ≤ p) (hpq : p ≤ q) :
eLpNorm' f p μ < ⊤
theorem MeasureTheory.MemLp.mono_exponent {α : Type u_1} {ε : Type u_2} {m : MeasurableSpace α} {μ : Measure α} {f : α → ε} [TopologicalSpace ε] [ContinuousENorm ε] {p q : ENNReal} [IsFiniteMeasure μ] (hfq : MemLp f q μ) (hpq : p ≤ q) :
MemLp f p μ
theorem MeasureTheory.MemLp.mono_exponent_of_measure_support_ne_top {α : Type u_1} {ε' : Type u_3} {m : MeasurableSpace α} {μ : Measure α} [TopologicalSpace ε'] [ESeminormedAddMonoid ε'] {p q : ENNReal} {f : α → ε'} (hfq : MemLp f q μ) {s : Set α} (hf : ∀ x ∉ s, f x = 0) (hs : μ s ≠ ⊤) (hpq : p ≤ q) :
MemLp f p μ

If a function is supported on a finite-measure set and belongs to ℒ^p, then it belongs to ℒ^q for any q ≤ p.

theorem MeasureTheory.eLpNorm_le_eLpNorm_top_mul_eLpNorm {α : Type u_1} {E : Type u_2} {F : Type u_3} {G : Type u_4} {m : MeasurableSpace α} [NormedAddCommGroup E] [NormedAddCommGroup F] [NormedAddCommGroup G] {μ : Measure α} (p : ENNReal) (f : α → E) {g : α → F} (hg : AEStronglyMeasurable g μ) (b : E → F → G) (c : NNReal) (h : ∀ᵐ (x : α) ∂μ, ‖b (f x) (g x)‖₊ ≤ c * ‖f x‖₊ * ‖g x‖₊) :
eLpNorm (fun (x : α) => b (f x) (g x)) p μ ≤ ↑c * eLpNorm f ⊤ μ * eLpNorm g p μ
theorem MeasureTheory.eLpNorm_le_eLpNorm_mul_eLpNorm_top {α : Type u_1} {E : Type u_2} {F : Type u_3} {G : Type u_4} {m : MeasurableSpace α} [NormedAddCommGroup E] [NormedAddCommGroup F] [NormedAddCommGroup G] {μ : Measure α} (p : ENNReal) {f : α → E} (hf : AEStronglyMeasurable f μ) (g : α → F) (b : E → F → G) (c : NNReal) (h : ∀ᵐ (x : α) ∂μ, ‖b (f x) (g x)‖₊ ≤ c * ‖f x‖₊ * ‖g x‖₊) :
eLpNorm (fun (x : α) => b (f x) (g x)) p μ ≤ ↑c * eLpNorm f p μ * eLpNorm g ⊤ μ
theorem MeasureTheory.eLpNorm'_le_eLpNorm'_mul_eLpNorm' {α : Type u_1} {E : Type u_2} {F : Type u_3} {G : Type u_4} {m : MeasurableSpace α} [NormedAddCommGroup E] [NormedAddCommGroup F] [NormedAddCommGroup G] {μ : Measure α} {f : α → E} {g : α → F} {p q r : ℝ} (hf : AEStronglyMeasurable f μ) (hg : AEStronglyMeasurable g μ) (b : E → F → G) (c : NNReal) (h : ∀ᵐ (x : α) ∂μ, ‖b (f x) (g x)‖₊ ≤ c * ‖f x‖₊ * ‖g x‖₊) (hro_lt : 0 < r) (hrp : r < p) (hpqr : 1 / r = 1 / p + 1 / q) :
eLpNorm' (fun (x : α) => b (f x) (g x)) r μ ≤ ↑c * eLpNorm' f p μ * eLpNorm' g q μ
theorem MeasureTheory.eLpNorm_le_eLpNorm_mul_eLpNorm_of_nnnorm {α : Type u_1} {E : Type u_2} {F : Type u_3} {G : Type u_4} {m : MeasurableSpace α} [NormedAddCommGroup E] [NormedAddCommGroup F] [NormedAddCommGroup G] {μ : Measure α} {f : α → E} {g : α → F} {p q r : ENNReal} (hf : AEStronglyMeasurable f μ) (hg : AEStronglyMeasurable g μ) (b : E → F → G) (c : NNReal) (h : ∀ᵐ (x : α) ∂μ, ‖b (f x) (g x)‖₊ ≤ c * ‖f x‖₊ * ‖g x‖₊) [hpqr : p.HolderTriple q r] :
eLpNorm (fun (x : α) => b (f x) (g x)) r μ ≤ ↑c * eLpNorm f p μ * eLpNorm g q μ

Hölder's inequality, as an inequality on the ℒp seminorm of an elementwise operation fun x => b (f x) (g x).

theorem MeasureTheory.eLpNorm_le_eLpNorm_mul_eLpNorm'_of_norm {α : Type u_1} {E : Type u_2} {F : Type u_3} {G : Type u_4} {m : MeasurableSpace α} [NormedAddCommGroup E] [NormedAddCommGroup F] [NormedAddCommGroup G] {μ : Measure α} {f : α → E} {g : α → F} {p q r : ENNReal} (hf : AEStronglyMeasurable f μ) (hg : AEStronglyMeasurable g μ) (b : E → F → G) (c : NNReal) (h : ∀ᵐ (x : α) ∂μ, ‖b (f x) (g x)‖ ≤ ↑c * ‖f x‖ * ‖g x‖) [hpqr : p.HolderTriple q r] :
eLpNorm (fun (x : α) => b (f x) (g x)) r μ ≤ ↑c * eLpNorm f p μ * eLpNorm g q μ

Hölder's inequality, as an inequality on the ℒp seminorm of an elementwise operation fun x => b (f x) (g x).

theorem MeasureTheory.MemLp.of_bilin {α : Type u_1} {E : Type u_2} {F : Type u_3} {G : Type u_4} {m : MeasurableSpace α} [NormedAddCommGroup E] [NormedAddCommGroup F] [NormedAddCommGroup G] {μ : Measure α} {p q r : ENNReal} {f : α → E} {g : α → F} (b : E → F → G) (c : NNReal) (hf : MemLp f p μ) (hg : MemLp g q μ) (h : AEStronglyMeasurable (fun (x : α) => b (f x) (g x)) μ) (hb : ∀ᵐ (x : α) ∂μ, ‖b (f x) (g x)‖₊ ≤ c * ‖f x‖₊ * ‖g x‖₊) [hpqr : p.HolderTriple q r] :
MemLp (fun (x : α) => b (f x) (g x)) r μ
theorem MeasureTheory.eLpNorm_smul_le_eLpNorm_top_mul_eLpNorm {𝕜 : Type u_1} {α : Type u_2} {E : Type u_3} {m : MeasurableSpace α} {μ : Measure α} [NormedRing 𝕜] [NormedAddCommGroup E] [MulActionWithZero 𝕜 E] [IsBoundedSMul 𝕜 E] {f : α → E} (p : ENNReal) (hf : AEStronglyMeasurable f μ) (φ : α → 𝕜) :
eLpNorm (φ • f) p μ ≤ eLpNorm φ ⊤ μ * eLpNorm f p μ
theorem MeasureTheory.eLpNorm_smul_le_eLpNorm_mul_eLpNorm_top {𝕜 : Type u_1} {α : Type u_2} {E : Type u_3} {m : MeasurableSpace α} {μ : Measure α} [NormedRing 𝕜] [NormedAddCommGroup E] [MulActionWithZero 𝕜 E] [IsBoundedSMul 𝕜 E] (p : ENNReal) (f : α → E) {φ : α → 𝕜} (hφ : AEStronglyMeasurable φ μ) :
eLpNorm (φ • f) p μ ≤ eLpNorm φ p μ * eLpNorm f ⊤ μ
theorem MeasureTheory.eLpNorm'_smul_le_mul_eLpNorm' {𝕜 : Type u_1} {α : Type u_2} {E : Type u_3} {m : MeasurableSpace α} {μ : Measure α} [NormedRing 𝕜] [NormedAddCommGroup E] [MulActionWithZero 𝕜 E] [IsBoundedSMul 𝕜 E] {p q r : ℝ} {f : α → E} (hf : AEStronglyMeasurable f μ) {φ : α → 𝕜} (hφ : AEStronglyMeasurable φ μ) (hp0_lt : 0 < p) (hpq : p < q) (hpqr : 1 / p = 1 / q + 1 / r) :
eLpNorm' (φ • f) p μ ≤ eLpNorm' φ q μ * eLpNorm' f r μ
theorem MeasureTheory.eLpNorm_smul_le_mul_eLpNorm {𝕜 : Type u_1} {α : Type u_2} {E : Type u_3} {m : MeasurableSpace α} {μ : Measure α} [NormedRing 𝕜] [NormedAddCommGroup E] [MulActionWithZero 𝕜 E] [IsBoundedSMul 𝕜 E] {p q r : ENNReal} {f : α → E} (hf : AEStronglyMeasurable f μ) {φ : α → 𝕜} (hφ : AEStronglyMeasurable φ μ) [hpqr : p.HolderTriple q r] :
eLpNorm (φ • f) r μ ≤ eLpNorm φ p μ * eLpNorm f q μ

Hölder's inequality, as an inequality on the ℒp seminorm of a scalar product φ • f.

theorem MeasureTheory.MemLp.smul {𝕜 : Type u_1} {α : Type u_2} {E : Type u_3} {m : MeasurableSpace α} {μ : Measure α} [NormedRing 𝕜] [NormedAddCommGroup E] [MulActionWithZero 𝕜 E] [IsBoundedSMul 𝕜 E] {p q r : ENNReal} {f : α → E} {φ : α → 𝕜} (hf : MemLp f q μ) (hφ : MemLp φ p μ) [hpqr : p.HolderTriple q r] :
MemLp (φ • f) r μ
theorem MeasureTheory.MemLp.mul {α : Type u_1} {x✝ : MeasurableSpace α} {𝕜 : Type u_2} [NormedRing 𝕜] {μ : Measure α} {p q r : ENNReal} {f φ : α → 𝕜} (hf : MemLp f q μ) (hφ : MemLp φ p μ) [hpqr : p.HolderTriple q r] :
MemLp (φ * f) r μ
theorem MeasureTheory.MemLp.mul' {α : Type u_1} {x✝ : MeasurableSpace α} {𝕜 : Type u_2} [NormedRing 𝕜] {μ : Measure α} {p q r : ENNReal} {f φ : α → 𝕜} (hf : MemLp f q μ) (hφ : MemLp φ p μ) [hpqr : p.HolderTriple q r] :
MemLp (fun (x : α) => φ x * f x) r μ

Variant of MemLp.mul where the function is written as fun x ↦ φ x * f x instead of φ * f.

theorem MeasureTheory.MemLp.prod {ι : Type u_1} {α : Type u_2} {𝕜 : Type u_3} {x✝ : MeasurableSpace α} [NormedCommRing 𝕜] {μ : Measure α} {f : ι → α → 𝕜} {p : ι → ENNReal} {s : Finset ι} (hf : ∀ i ∈ s, MemLp (f i) (p i) μ) :
MemLp (∏ i ∈ s, f i) (∑ i ∈ s, (p i)⁻¹)⁻¹ μ

See MemLp.prod' for the applied version.

theorem MeasureTheory.MemLp.prod' {ι : Type u_1} {α : Type u_2} {𝕜 : Type u_3} {x✝ : MeasurableSpace α} [NormedCommRing 𝕜] {μ : Measure α} {f : ι → α → 𝕜} {p : ι → ENNReal} {s : Finset ι} (hf : ∀ i ∈ s, MemLp (f i) (p i) μ) :
MemLp (fun (ω : α) => ∏ i ∈ s, f i ω) (∑ i ∈ s, (p i)⁻¹)⁻¹ μ

See MemLp.prod for the unapplied version.