E Lp Norm cz Operator restrict two three of support subset
eLpNorm_czOperator_restrict_two_three_of_support_subset
Plain-language statement
The operator czOperator K r is bounded from L^2 ([1, 4]) to L^2 ([2, 3]), uniformly in r. This follows from the fact, proved in norm_czOperator_le_add, that it is bounded by the sum of two operators which are both bounded: one is the convolution with dirichletApprox, bounded as it is an average of Fourier projections, and the other one has a k...
Exact Lean statement
lemma eLpNorm_czOperator_restrict_two_three_of_support_subset {g : ℝ → ℂ} {r : ℝ}
(hr : r ∈ Ioo 0 1) (hg : MemLp g ∞ volume) (h'g : support g ⊆ Icc 1 4) :
eLpNorm (czOperator K r g) 2 (volume.restrict (Ioc 2 3)) ≤
2 ^ 8 * eLpNorm g 2 (volume.restrict (Ioc 1 4))Formal artifact
Lean source
lemma eLpNorm_czOperator_restrict_two_three_of_support_subset {g : ℝ → ℂ} {r : ℝ} (hr : r ∈ Ioo 0 1) (hg : MemLp g ∞ volume) (h'g : support g ⊆ Icc 1 4) : eLpNorm (czOperator K r g) 2 (volume.restrict (Ioc 2 3)) ≤ 2 ^ 8 * eLpNorm g 2 (volume.restrict (Ioc 1 4)) := by have I : 0 ≤ 2 * π := by linarith [Real.pi_nonneg] set n := ⌈r⁻¹⌉₊ with hn calc eLpNorm (czOperator K r g) 2 (volume.restrict (Ioc 2 3)) _ ≤ eLpNorm (fun x ↦ ‖∫ y in (0)..(2 * π), g y * dirichletApprox n (x - y)‖ + 12 * ∫ y in Ioc 0 (2 * π), ‖g y‖ * niceKernel r (x - y)) 2 (volume.restrict (Ioc 2 3)) := by apply eLpNorm_mono_ae_real filter_upwards [self_mem_ae_restrict measurableSet_Ioc] with x hx apply norm_czOperator_le_add hr hn hg hx.1.le hx.2 h'g _ ≤ eLpNorm (fun x ↦ ‖∫ y in (0)..(2 * π), g y * dirichletApprox n (x - y)‖ + 12 * ∫ y in Ioc 0 (2 * π), ‖g y‖ * niceKernel r (x - y)) 2 (volume.restrict (Ioc 0 (2 * π))) := by apply eLpNorm_mono_measure apply Measure.restrict_mono _ le_rfl apply Ioc_subset_Ioc (by norm_num) linarith [Real.pi_gt_three] _ ≤ eLpNorm (fun x ↦ ‖∫ y in (0)..(2 * π), g y * dirichletApprox n (x - y)‖) 2 (volume.restrict (Ioc 0 (2 * π))) + eLpNorm (fun x ↦ 12 * ∫ y in Ioc 0 (2 * π), ‖g y‖ * niceKernel r (x - y)) 2 (volume.restrict (Ioc 0 (2 * π))) := by apply eLpNorm_add_le _ _ one_le_two · apply AEStronglyMeasurable.norm simp_rw [intervalIntegral.integral_of_le I] let L := ContinuousLinearMap.mul ℂ ℂ let w : ℝ × ℝ → ℂ := fun p ↦ L (g p.2) (dirichletApprox n (p.1 - p.2)) change AEStronglyMeasurable (fun x ↦ ∫ (y : ℝ) in Ioc 0 (2 * π), w (x, y) ∂volume) (volume.restrict (Ioc 0 (2 * π))) apply AEStronglyMeasurable.integral_prod_right' apply (hg.restrict _).aestronglyMeasurable.convolution_integrand' fun_prop · apply AEStronglyMeasurable.const_mul let L := ContinuousLinearMap.mul ℝ ℝ let w : ℝ × ℝ → ℝ := fun p ↦ L (‖g p.2‖) (niceKernel r (p.1 - p.2)) change AEStronglyMeasurable (fun x ↦ ∫ (y : ℝ) in Ioc 0 (2 * π), w (x, y) ∂volume) (volume.restrict (Ioc 0 (2 * π))) apply AEStronglyMeasurable.integral_prod_right' apply (hg.norm.restrict _).aestronglyMeasurable.convolution_integrand' fun_prop _ ≤ 7 * eLpNorm g 2 (volume.restrict (Ioc 0 (2 * π))) + 12 * (17 * eLpNorm g 2 (volume.restrict (Ioc 0 (2 * π)))) := by gcongr · rw [eLpNorm_norm] exact eLpNorm_convolution_dirichletApprox hg change eLpNorm ((12 : ℝ) • fun x ↦ ∫ (y : ℝ) in Ioc 0 (2 * π), ‖g y‖ * niceKernel r (x - y)) 2 (volume.restrict (Ioc 0 (2 * π))) ≤ _ rw [eLpNorm_const_smul] gcongr · simp [enorm] have W := integrable_bump_convolution (f := fun x ↦ ‖g x‖) (g := fun x ↦ niceKernel r x) hg.norm ?_ ?_ ?_ (r := r) ?_ · simpa [intervalIntegral.integral_of_le I] using W · apply memLp_top_of_bound (by fun_prop) (r⁻¹) (Eventually.of_forall (fun y ↦ ?_)) simp [abs_of_nonneg (niceKernel_pos hr.1).le, niceKernel_le_inv] · apply niceKernel_periodic · exact ⟨hr.1, hr.2.trans (by linarith [Real.pi_gt_three])⟩ · simp [abs_of_nonneg (niceKernel_pos hr.1).le] _ = 211 * eLpNorm g 2 (volume.restrict (Ioc 0 (2 * π))) := by ring _ ≤ 2 ^ 8 * eLpNorm g 2 (volume.restrict (Ioc 0 (2 * π))) := by gcongr norm_num _ = 2 ^ 8 * eLpNorm g 2 (volume.restrict (Ioc 1 4)) := by congr 1 rw [restrict_Ioc_eq_restrict_Icc, restrict_Ioc_eq_restrict_Icc] have : volume.restrict (Icc 1 4) = (volume.restrict (Icc 0 (2 * π))).restrict (Icc 1 4) := by rw [Measure.restrict_restrict_of_subset] apply Icc_subset_Icc (by norm_num) (by linarith [Real.pi_gt_three]) rw [this] apply (eLpNorm_restrict_eq_of_support_subset h'g).symm- Project
- Carleson formalization
- License
- Apache-2.0
- Commit
- 74ef907d6bdb
- Source
- Carleson/Classical/HilbertStrongType.lean:769-840
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Related declarations
Adjoint Carleson adjoint
adjointCarleson_adjoint
Plain-language statement
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Source project: Carleson formalization
Person-level attribution pending.
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ae_tendsto_zero_of_distribution_le
Plain-language statement
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Source project: Carleson formalization
Person-level attribution pending.
Antichain operator
antichain_operator
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Source project: Carleson formalization
Person-level attribution pending.