openAI-math-dataset / lean /OAI /Analysis /Conductivity /Geometry /BoxMomentRightInverse.lean
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Add lean source and binary files (part 15)
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import Mathlib
import OAI.Analysis.Conductivity.Variational.CompactRegularCorrection
import OAI.Analysis.Conductivity.Flux.CompactInteriorDivergence
import OAI.Analysis.Conductivity.Variational.FiniteMomentTransfer
namespace OAI
noncomputable section
namespace ScalarConductivity
open Set MeasureTheory
lemma exists_unit_global_interval_bump {a b : ℝ} (hab : a<b) :
∃ η : ℝ → ℝ, ContDiff ℝ (↑(⊤ : ℕ∞)) η ∧ HasCompactSupport η ∧
tsupport η⊆Ioo a b ∧ (∫ t,η t)=1 := by
obtain ⟨η,hη,hs,hv,hi⟩ := exists_unit_interval_bump hab
refine ⟨η,hη,hs,hv,?_⟩
rw [intervalIntegral.integral_of_le hab.le] at hi
have he : (∫ t in Ioc a b,η t)=(∫ t,η t) := by
apply setIntegral_eq_integral_of_forall_compl_eq_zero
intro t ht
exact image_eq_zero_of_notMem_tsupport (fun hh => ht ⟨(hv hh).1,(hv hh).2.le⟩)
rwa [he] at hi
lemma exists_unit_box_bump {a b : Fin 3 → ℝ} (hab : ∀ i,a i<b i) :
∃ K : Box3 → ℝ,ContDiff ℝ (↑(⊤ : ℕ∞)) K ∧ HasCompactSupport K ∧
tsupport K⊆(Ioo (a 0) (b 0) ×ˢ Ioo (a 1) (b 1)) ×ˢ Ioo (a 2) (b 2) ∧
(∫ p,K p)=1 := by
obtain ⟨η₁,h₁,hs₁,hv₁,hi₁⟩ := exists_unit_global_interval_bump (hab 0)
obtain ⟨η₂,h₂,hs₂,hv₂,hi₂⟩ := exists_unit_global_interval_bump (hab 1)
obtain ⟨η₃,h₃,hs₃,hv₃,hi₃⟩ := exists_unit_global_interval_bump (hab 2)
let K : Box3 → ℝ := fun p => (η₁ p.1.1*η₂ p.1.2)*η₃ p.2
have hK : ContDiff ℝ (↑(⊤ : ℕ∞)) K :=
((h₁.comp (contDiff_fst.comp contDiff_fst)).mul
(h₂.comp (contDiff_snd.comp contDiff_fst))).mul (h₃.comp contDiff_snd)
have hsK : HasCompactSupport K := by
apply HasCompactSupport.of_support_subset_isCompact ((hs₁.prod hs₂).prod hs₃)
intro p hp
have hh := mul_ne_zero_iff.mp hp
have hh' := mul_ne_zero_iff.mp hh.1
exact ⟨⟨subset_tsupport η₁ hh'.1,subset_tsupport η₂ hh'.2⟩,subset_tsupport η₃ hh.2⟩
have htK : tsupport K⊆(tsupport η₁ ×ˢ tsupport η₂) ×ˢ tsupport η₃ := by
apply closure_minimal _ ((hs₁.isClosed.prod hs₂.isClosed).prod hs₃.isClosed)
intro p hp
have hh := mul_ne_zero_iff.mp hp
have hh' := mul_ne_zero_iff.mp hh.1
exact ⟨⟨subset_tsupport η₁ hh'.1,subset_tsupport η₂ hh'.2⟩,subset_tsupport η₃ hh.2⟩
refine ⟨K,hK,hsK,htK.trans (prod_mono (prod_mono hv₁ hv₂) hv₃),?_⟩
change (∫ p : (ℝ×ℝ)×ℝ,(η₁ p.1.1*η₂ p.1.2)*η₃ p.2)=1
rw [Measure.volume_eq_prod,integral_prod_mul (fun p : ℝ×ℝ => η₁ p.1*η₂ p.2) η₃,
Measure.volume_eq_prod,integral_prod_mul η₁ η₂,hi₁,hi₂,hi₃]
norm_num
lemma cubePartial_integral_zero {K : Box3 → ℝ}
(hK : ContDiff ℝ (↑(⊤ : ℕ∞)) K) (hs : HasCompactSupport K) (v : Box3) :
(∫ p,cubePartial K v p)=0 := by
have hh := cube_integration_by_parts (f := fun _ => (1:ℝ)) contDiff_const hK hs v
simpa [cubePartial] using hh
theorem box_moment_right_inverse {a b : Fin 3 → ℝ} (hab : ∀ i,a i<b i)
(m : Fin 3 → ℝ) :
∃ r₁ r₂ : Box3 → ℝ,
ContDiff ℝ (↑(⊤ : ℕ∞)) r₁ ∧ ContDiff ℝ (↑(⊤ : ℕ∞)) r₂ ∧
HasCompactSupport r₁ ∧ HasCompactSupport r₂ ∧
tsupport r₁⊆(Ioo (a 0) (b 0) ×ˢ Ioo (a 1) (b 1)) ×ˢ Ioo (a 2) (b 2) ∧
tsupport r₂⊆(Ioo (a 0) (b 0) ×ˢ Ioo (a 1) (b 1)) ×ˢ Ioo (a 2) (b 2) ∧
(∫ p,r₁ p)=m 0 ∧ (∫ p,r₂ p)=m 1 ∧
(∫ p,p.1.2*r₁ p-p.1.1*r₂ p)=m 2 := by
obtain ⟨K,hK,hs,hv,hi⟩ := exists_unit_box_bump hab
let D := cubePartial K ((0,1),0)
let c := m 0*(∫ p : Box3,p.1.2*K p)-m 1*(∫ p : Box3,p.1.1*K p)-m 2
let r₁ := fun p => m 0*K p+c*D p
let r₂ := fun p => m 1*K p
have hD : ContDiff ℝ (↑(⊤ : ℕ∞)) D := cubePartial_smooth hK _
have hsD : HasCompactSupport D := cubePartial_compact hs _
have hvD : tsupport D⊆(Ioo (a 0) (b 0) ×ˢ Ioo (a 1) (b 1)) ×ˢ Ioo (a 2) (b 2) :=
(cubePartial_tsupport _).trans hv
have iK : Integrable K := hK.continuous.integrable_of_hasCompactSupport hs
have iD : Integrable D := hD.continuous.integrable_of_hasCompactSupport hsD
have hDz : (∫ p,D p)=0 := cubePartial_integral_zero hK hs _
have hf₁ : ContDiff ℝ (↑(⊤ : ℕ∞)) (fun p : Box3 => p.1.1) := contDiff_fst.comp contDiff_fst
have hf₂ : ContDiff ℝ (↑(⊤ : ℕ∞)) (fun p : Box3 => p.1.2) := contDiff_snd.comp contDiff_fst
have hDm : (∫ p : Box3,p.1.2*D p)= -1 := by
have hh := cube_integration_by_parts hf₂ hK hs ((0,1),0)
simpa only [cubePartial_snd_fst,one_mul,hi] using hh
have iK₁ : Integrable (fun p : Box3 => p.1.1*K p) :=
(hf₁.continuous.mul hK.continuous).integrable_of_hasCompactSupport hs.mul_left
have iK₂ : Integrable (fun p : Box3 => p.1.2*K p) :=
(hf₂.continuous.mul hK.continuous).integrable_of_hasCompactSupport hs.mul_left
have iD₂ : Integrable (fun p : Box3 => p.1.2*D p) :=
(hf₂.continuous.mul hD.continuous).integrable_of_hasCompactSupport hsD.mul_left
refine ⟨r₁,r₂,(contDiff_const.mul hK).add (contDiff_const.mul hD),
contDiff_const.mul hK,(hs.mul_left).add hsD.mul_left,hs.mul_left,?_,?_,?_,?_,?_⟩
· exact (tsupport_add _ _).trans (union_subset
(tsupport_mul_subset_right.trans hv) (tsupport_mul_subset_right.trans hvD))
· exact tsupport_mul_subset_right.trans hv
· dsimp only [r₁]
rw [integral_add (iK.const_mul _) (iD.const_mul _),integral_const_mul,integral_const_mul,hi,hDz]
ring
· dsimp only [r₂]
rw [integral_const_mul,hi,mul_one]
· have he : (fun p : Box3 => p.1.2*r₁ p-p.1.1*r₂ p)=
(fun p => m 0*(p.1.2*K p)+c*(p.1.2*D p)-m 1*(p.1.1*K p)) := by
funext p; dsimp only [r₁,r₂]; ring
have iKD : Integrable (fun p : Box3 => m 0*(p.1.2*K p)+c*(p.1.2*D p)) :=
(iK₂.const_mul _).add (iD₂.const_mul _)
rw [he,integral_sub iKD (iK₁.const_mul _),
integral_add (iK₂.const_mul _) (iD₂.const_mul _),integral_const_mul,integral_const_mul,
integral_const_mul,hDm]
dsimp only [c]
ring
end ScalarConductivity
namespace ScalarConductivity
open Set MeasureTheory
theorem box_moment_bounded_right_inverse {a b : Fin 3 → ℝ} (hab : ∀ i,a i<b i) :
∃ g : Fin 3 → Fin 2 → Box3 → ℝ,
(∀ i j,ContDiff ℝ (↑(⊤ : ℕ∞)) (g i j)) ∧
(∀ i j,HasCompactSupport (g i j)) ∧
(∀ i j,tsupport (g i j)⊆(Ioo (a 0) (b 0) ×ˢ Ioo (a 1) (b 1)) ×ˢ Ioo (a 2) (b 2)) ∧
(∀ m : Fin 3 → ℝ,
(∫ p,∑ i,m i*g i 0 p)=m 0 ∧
(∫ p,∑ i,m i*g i 1 p)=m 1 ∧
(∫ p,p.1.2*(∑ i,m i*g i 0 p)-p.1.1*(∑ i,m i*g i 1 p))=m 2) ∧
(∀ j n,∃ B : ℝ,0<B ∧ ∀ (m : Fin 3 → ℝ) (p : Box3),
‖iteratedFDeriv ℝ n (fun p => ∑ i,m i*g i j p) p‖≤B*‖m‖) := by
choose g₀ g₁ hg₀ hg₁ hs₀ hs₁ hv₀ hv₁ hi₀ hi₁ hit using
fun i : Fin 3 => box_moment_right_inverse hab (Pi.single i 1)
let g : Fin 3 → Fin 2 → Box3 → ℝ := fun i => ![g₀ i,g₁ i]
have hg (i : Fin 3) (j : Fin 2) : ContDiff ℝ (↑(⊤ : ℕ∞)) (g i j) := by
fin_cases j
· exact hg₀ i
· exact hg₁ i
have hs (i : Fin 3) (j : Fin 2) : HasCompactSupport (g i j) := by
fin_cases j
· exact hs₀ i
· exact hs₁ i
have hv (i : Fin 3) (j : Fin 2) : tsupport (g i j)⊆
(Ioo (a 0) (b 0) ×ˢ Ioo (a 1) (b 1)) ×ˢ Ioo (a 2) (b 2) := by
fin_cases j
· exact hv₀ i
· exact hv₁ i
have hm (i : Fin 3) (j : Fin 2) : (∫ p,g i j p)=(Pi.single i (1 : ℝ) : Fin 3 → ℝ) (j.castLE (by decide : 2≤3)) := by
fin_cases j
· exact hi₀ i
· exact hi₁ i
have hmt (i : Fin 3) : (∫ p : Box3,p.1.2*g i 0 p-p.1.1*g i 1 p)= (Pi.single i (1 : ℝ) : Fin 3 → ℝ) 2 := hit i
have hI (i : Fin 3) (j : Fin 2) : Integrable (g i j) :=
(hg i j).continuous.integrable_of_hasCompactSupport (hs i j)
refine ⟨g,hg,hs,hv,?_,?_⟩
· intro m
have hh (j : Fin 2) : (∫ p,∑ i,m i*g i j p)=m (j.castLE (by decide : 2≤3)) := by
rw [integral_finsetSum _ (fun i _ => (hI i j).const_mul (m i))]
simp_rw [integral_const_mul,hm]
simp [Pi.single_apply]
refine ⟨hh 0,hh 1,?_⟩
have hU : ContDiff ℝ (↑(⊤ : ℕ∞)) (fun p : Box3 => p.1.1) := contDiff_fst.comp contDiff_fst
have hV : ContDiff ℝ (↑(⊤ : ℕ∞)) (fun p : Box3 => p.1.2) := contDiff_snd.comp contDiff_fst
have htI (i : Fin 3) : Integrable (fun p : Box3 => p.1.2*g i 0 p-p.1.1*g i 1 p) :=
((hV.continuous.mul (hg i 0).continuous).integrable_of_hasCompactSupport (hs i 0).mul_left).sub
((hU.continuous.mul (hg i 1).continuous).integrable_of_hasCompactSupport (hs i 1).mul_left)
have he : (fun p : Box3 => p.1.2*(∑ i,m i*g i 0 p)-p.1.1*(∑ i,m i*g i 1 p))=
(fun p => ∑ i,m i*(p.1.2*g i 0 p-p.1.1*g i 1 p)) := by
funext p
simp only [Finset.mul_sum,←Finset.sum_sub_distrib]
apply Finset.sum_congr rfl
intro i _
ring
rw [he,integral_finsetSum _ (fun i _ => (htI i).const_mul (m i))]
simp_rw [integral_const_mul,hmt]
simp [Pi.single_apply]
· intro j n
obtain ⟨B,hB,hbound⟩ := fixed_smooth_tests_bound (fun i => g i j)
(fun i => hg i j) (fun i => hs i j) n
refine ⟨B,hB,?_⟩
intro m p
simpa only [smul_eq_mul] using hbound m ‖m‖ (norm_nonneg _) (norm_le_pi_norm m) p
end ScalarConductivity
end
end OAI