fpvandoorn/carleson
Source indexedlemma · leanprover/lean4:v4.32.0
lintegral_carlesonSum_forest'
Carleson.Discrete.ForestUnion · Carleson/Discrete/ForestUnion.lean:796 to 831
Source documentation
For each forest, the integral of the norm of the Carleson sum can be controlled thanks to
the forest theorem and to the density control coming from the fact we are away from G₁. Second
version, with the volume of F.
Exact Lean statement
lemma lintegral_carlesonSum_forest'
{f : X → ℂ} (hf : Measurable f) (h2f : ∀ x, ‖f x‖ ≤ F.indicator 1 x) :
∫⁻ x in G \ G', ‖carlesonSum (⋃ u ∈ 𝔘₄ k n j l, 𝔗₂ k n j u) f x‖ₑ ≤
C2_0_4 a q n * 2 ^ (a + 5/2 : ℝ) * (volume G) ^ (1 - q⁻¹) * (volume F) ^ (q⁻¹)Complete declaration
Lean source
Full Lean sourceLean 4
lemma lintegral_carlesonSum_forest' {f : X → ℂ} (hf : Measurable f) (h2f : ∀ x, ‖f x‖ ≤ F.indicator 1 x) : ∫⁻ x in G \ G', ‖carlesonSum (⋃ u ∈ 𝔘₄ k n j l, 𝔗₂ k n j u) f x‖ₑ ≤ C2_0_4 a q n * 2 ^ (a + 5/2 : ℝ) * (volume G) ^ (1 - q⁻¹) * (volume F) ^ (q⁻¹) := by apply (lintegral_carlesonSum_forest hf h2f).trans simp only [mul_assoc] apply mul_le_mul_right simp only [div_eq_mul_inv, one_mul, ENNReal.mul_rpow_of_nonneg _ _ (inv_q_sub_half_nonneg X), ← ENNReal.rpow_natCast, ← ENNReal.rpow_mul] calc 2 ^ ((2 * a + 5 : ℕ) * (q⁻¹ - 2⁻¹)) * volume F ^ (q⁻¹ - 2⁻¹) * (volume G)⁻¹ ^ (q⁻¹ - 2⁻¹) * (volume F ^ (2⁻¹ : ℝ) * volume G ^ (2⁻¹ : ℝ)) _ ≤ 2 ^ (a + 5/2 : ℝ) * volume F ^ (q⁻¹ - 2⁻¹) * (volume G)⁻¹ ^ (q⁻¹ - 2⁻¹) * ((volume F) ^ (2⁻¹ : ℝ) * volume G ^ (2⁻¹ : ℝ)) := by gcongr · exact one_le_two have : 1 ≤ q := (one_lt_q X).le have : (2 * a + 5 : ℕ) * (q⁻¹ - 2⁻¹) ≤ (2 * a + 5 : ℕ) * (1⁻¹ - 2⁻¹) := by gcongr apply this.trans_eq norm_num simp [add_mul, div_eq_mul_inv] ring _ = 2 ^ (a + 5/2 : ℝ) * (volume G ^ (1 - q⁻¹) * volume F ^ q⁻¹) := by rcases eq_or_ne (volume G) 0 with vG | vG · have : 0 < 1 - q⁻¹ := by rw [sub_pos, inv_lt_one_iff₀]; exact .inr (one_lt_q X) rw [vG, ENNReal.zero_rpow_of_pos (by positivity), ENNReal.zero_rpow_of_pos this] simp only [zero_mul, mul_zero] · have IF : (volume F) ^ (q⁻¹) = (volume F) ^ ((q ⁻¹ - 2⁻¹) + 2⁻¹) := by congr; abel have IG : (volume G) ^ (1 - q⁻¹) = (volume G) ^ (2⁻¹ - (q⁻¹ - 2⁻¹)) := by congr 1 simp only [sub_sub_eq_add_sub, sub_left_inj] norm_num rw [IF, IG, ENNReal.rpow_sub _ _ vG volume_G_ne_top, ENNReal.rpow_add_of_nonneg (x := volume F) _ _ (inv_q_sub_half_nonneg X) (by norm_num), ENNReal.div_eq_inv_mul, ENNReal.inv_rpow] ring