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Sync missing files (lean, preprints, history.md); remove stale build artifacts (part 7)

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  1. lean/OAI/Probability/SLE/Mass/LevelRandomRadon.lean +107 -0
  2. lean/OAI/Probability/SLE/Mass/LevelRemainderMeasure.lean +113 -0
  3. lean/OAI/Probability/SLE/Mass/LevelRemainderSupport.lean +87 -0
  4. lean/OAI/Probability/SLE/Mass/LevelStoppingConvex.lean +128 -0
  5. lean/OAI/Probability/SLE/Mass/LevelStoppingGreenLimit.lean +131 -0
  6. lean/OAI/Probability/SLE/Mass/LevelStoppingKernel.lean +230 -0
  7. lean/OAI/Probability/SLE/Mass/LevelStoppingMeasures.lean +280 -0
  8. lean/OAI/Probability/SLE/Mass/LevelStoppingSpatialKernel.lean +114 -0
  9. lean/OAI/Probability/SLE/Mass/LevelStoppingTests.lean +146 -0
  10. lean/OAI/Probability/SLE/Mass/LocalGridMass.lean +118 -0
  11. lean/OAI/Probability/SLE/Mass/LocallyFiniteMeasureSubtract.lean +49 -0
  12. lean/OAI/Probability/SLE/Mass/MarkedTubeHarmonicMeasure.lean +103 -0
  13. lean/OAI/Probability/SLE/Mass/MassCompensatorEndpoint.lean +117 -0
  14. lean/OAI/Probability/SLE/Mass/MassCompensatorMesh.lean +146 -0
  15. lean/OAI/Probability/SLE/Mass/MassCompensatorRecovery.lean +144 -0
  16. lean/OAI/Probability/SLE/Mass/MassCompensatorSelection.lean +81 -0
  17. lean/OAI/Probability/SLE/Mass/MassCompensatorVariance.lean +192 -0
  18. lean/OAI/Probability/SLE/Mass/MassGridCutoffs.lean +105 -0
  19. lean/OAI/Probability/SLE/Mass/MassGridOverlap.lean +91 -0
  20. lean/OAI/Probability/SLE/Mass/MassKernelUniqueness.lean +51 -0
  21. lean/OAI/Probability/SLE/Mass/MassMartingaleTesting.lean +75 -0
  22. lean/OAI/Probability/SLE/Mass/MassMartingaleUniqueness.lean +123 -0
  23. lean/OAI/Probability/SLE/Mass/MassPotentialCompensator.lean +57 -0
  24. lean/OAI/Probability/SLE/Mass/MassUniquenessMesh.lean +81 -0
  25. lean/OAI/Probability/SLE/Mass/MassUniquenessPartitions.lean +87 -0
  26. lean/OAI/Probability/SLE/Mass/MassUniquenessSeparation.lean +124 -0
  27. lean/OAI/Probability/SLE/Mass/MomentLevels.lean +77 -0
  28. lean/OAI/Probability/SLE/Mass/MonotoneMassExhaustion.lean +33 -0
  29. lean/OAI/Probability/SLE/Mass/NonnegativeL2Passage.lean +56 -0
  30. lean/OAI/Probability/SLE/Mass/NormalizedDiskCompensator.lean +92 -0
  31. lean/OAI/Probability/SLE/Mass/OriginalShiftedMass.lean +58 -0
  32. lean/OAI/Probability/SLE/Mass/PastThresholdMass.lean +63 -0
  33. lean/OAI/Probability/SLE/Mass/PhysicalDiskMass.lean +94 -0
  34. lean/OAI/Probability/SLE/Mass/PositiveMassContinuity.lean +37 -0
  35. lean/OAI/Probability/SLE/Mass/PositiveMassGerm.lean +98 -0
  36. lean/OAI/Probability/SLE/Mass/PositiveRestartMass.lean +167 -0
  37. lean/OAI/Probability/SLE/Mass/PositiveTraceMass.lean +72 -0
  38. lean/OAI/Probability/SLE/Mass/RadonApproximationList.lean +56 -0
  39. lean/OAI/Probability/SLE/Mass/RadonFactorization.lean +97 -0
  40. lean/OAI/Probability/SLE/Mass/RadonKernelIntegral.lean +67 -0
  41. lean/OAI/Probability/SLE/Mass/RadonPathCertificates.lean +77 -0
  42. lean/OAI/Probability/SLE/Mass/RadonProcessAEUniqueness.lean +39 -0
  43. lean/OAI/Probability/SLE/Mass/RadonProcessUniqueness.lean +51 -0
  44. lean/OAI/Probability/SLE/Mass/RadonRandomTesting.lean +64 -0
  45. lean/OAI/Probability/SLE/Mass/RadonTerminalUniqueness.lean +49 -0
  46. lean/OAI/Probability/SLE/Mass/RadonTestDetermines.lean +49 -0
  47. lean/OAI/Probability/SLE/Mass/RadonTestFamily.lean +118 -0
  48. lean/OAI/Probability/SLE/Mass/RadonTestLimit.lean +138 -0
  49. lean/OAI/Probability/SLE/Mass/RadonTestLimitProperties.lean +101 -0
  50. lean/OAI/Probability/SLE/Mass/RadonTestMeasurability.lean +138 -0
lean/OAI/Probability/SLE/Mass/LevelRandomRadon.lean ADDED
@@ -0,0 +1,107 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Mass.LevelRadonExtraction
2
+ import OAI.Probability.SLE.Mass.RandomRadonLimit
3
+ import OAI.Probability.SLE.Mass.RadonTestLimitProperties
4
+
5
+ namespace OAI
6
+
7
+ /-! Measurable versions and simultaneous time ordering of the actual
8
+ common Radon limits. -/
9
+
10
+ noncomputable section
11
+ open Set Filter MeasureTheory ProbabilityTheory Classical
12
+ open scoped NNReal ENNReal Topology CompactlySupported
13
+
14
+ namespace SLEExactGauge.Multipoint
15
+
16
+ local instance : LocallyCompactSpace upperHalfPlane := isOpen_upperHalfPlane.locallyCompactSpace
17
+
18
+ lemma halfPlaneLevelMeasure_mono
19
+ {Ω : Type*} (κ : ℝ) (B : ℝ≥0 → Ω → ℝ)
20
+ (γ : Ω → ℝ≥0 → ℂ) (G : Ω → ℝ≥0 → ℂ → ℂ) (u : ℝ) (ω : Ω) :
21
+ Monotone (fun t => halfPlaneLevelMeasure κ B γ G u t ω) := by
22
+ intro s t hst
23
+ apply Measure.le_iff.mpr
24
+ intro A hA
25
+ simp only [halfPlaneLevelMeasure,comap_subtype_coe_apply isOpen_upperHalfPlane.measurableSet]
26
+ exact levelApproximation_mono κ B γ G u ω hst _
27
+
28
+ lemma convexLevelMeasure_mono
29
+ {Ω : Type*} (κ : ℝ) (B : ℝ≥0 → Ω → ℝ)
30
+ (γ : Ω → ℝ≥0 → ℂ) (G : Ω → ℝ≥0 → ℂ → ℂ) (u : ℕ → ℝ)
31
+ (s : ℕ → Finset ℕ) (w : ℕ → ℕ → ℝ) (n : ℕ) (ω : Ω) :
32
+ Monotone (fun t => convexLevelMeasure κ B γ G u s w n t ω) := by
33
+ intro t₁ t₂ ht
34
+ apply Measure.le_iff.mpr
35
+ intro A hA
36
+ simp only [convexLevelMeasure,Measure.finsetSum_apply,Measure.smul_apply,smul_eq_mul]
37
+ exact Finset.sum_le_sum (fun i _ => mul_le_mul' le_rfl
38
+ (halfPlaneLevelMeasure_mono κ B γ G (u (n+i)) ω ht A))
39
+
40
+ lemma convexLevelMeasure_test_measurable
41
+ {Ω : Type*} [MeasurableSpace Ω] {B : ℝ≥0 → Ω → ℝ}
42
+ (hm : ∀ t, Measurable (B t)) (hBc : ∀ ω, Continuous (fun t => B t ω))
43
+ {κ : ℝ} (hκ : 0 < κ) (hκ8 : κ < 8)
44
+ (γ : Ω → ℝ≥0 → ℂ) (G F : Ω → ℝ≥0 → ℂ → ℂ)
45
+ (hw : ∀ ω, IsCapacityTwoWitness (fun t => Real.sqrt κ * B t ω) (γ ω) (G ω) (F ω))
46
+ (u : ℕ → ℝ) (hu : ∀ n, 0 ≤ u n) (s : ℕ → Finset ℕ) (w : ℕ → ℕ → ℝ)
47
+ (hw₀ : ∀ n i, i ∈ s n → 0 ≤ w n i) (n : ℕ) (t : ℝ≥0∞)
48
+ (f : C_c(upperHalfPlane,ℝ)) :
49
+ Measurable (fun ω => ∫ z, f z ∂convexLevelMeasure κ B γ G u s w n t ω) := by
50
+ have he (ω : Ω) := integral_convexLevelMeasure hκ hκ8 γ G F ω (hBc ω) (hw ω)
51
+ u s w n t (hw₀ n) f
52
+ simp_rw [he]
53
+ apply Finset.measurable_sum
54
+ intro i hi
55
+ exact measurable_const.mul (levelApproximationRealTest_measurable hm hBc κ (u (n+i))
56
+ (hu (n+i)) γ G F hw t (extendHalfPlaneTest f)
57
+ (extendHalfPlaneTest_measurable f f.continuous.measurable))
58
+
59
+ theorem exists_measurable_level_radon_limits
60
+ {Ω : Type*} [MeasurableSpace Ω]
61
+ {P : Measure Ω} {B : ℝ≥0 → Ω → ℝ} (hB : IsBrownianReal B P)
62
+ (hm : ∀ t, Measurable (B t)) (hBm : Measurable (Function.uncurry B))
63
+ (hBc : ∀ ω, Continuous (fun t => B t ω)) (hB0 : ∀ ω, B 0 ω = 0)
64
+ {κ : ℝ} (hκ : 0 < κ) (hκ8 : κ < 8)
65
+ (γ : Ω → ℝ≥0 → ℂ) (G F : Ω → ℝ≥0 → ℂ → ℂ)
66
+ (hw : ∀ ω, IsCapacityTwoWitness (fun t => Real.sqrt κ * B t ω) (γ ω) (G ω) (F ω))
67
+ (hgrowth : PublishedDiskUnivalentGrowth)
68
+ (u : ℕ → ℝ) (hu : ∀ n, 0 ≤ u n) (t : ℕ → ℝ≥0∞) :
69
+ ∃ s : ℕ → Finset ℕ, ∃ w : ℕ → ℕ → ℝ, ∃ ν : ℕ → Ω → Measure upperHalfPlane,
70
+ (∀ n i, i ∈ s n → 0 ≤ w n i) ∧ (∀ n, ∑ i ∈ s n, w n i = 1) ∧
71
+ (∀ j, Measurable (ν j)) ∧
72
+ (∀ j ω, (ν j ω).Regular ∧ IsFiniteMeasureOnCompacts (ν j ω)) ∧
73
+ (∀ᵐ ω ∂P,
74
+ (∀ j (f : C_c(upperHalfPlane,ℝ)),
75
+ Tendsto (fun n => ∫ z, f z ∂convexLevelMeasure κ B γ G u s w n (t j) ω)
76
+ atTop (𝓝 (∫ z, f z ∂ν j ω))) ∧
77
+ ∀ i j, t i ≤ t j → ν i ω ≤ ν j ω) := by
78
+ obtain ⟨s,w,hw₀,hw₁,hex⟩ := exists_common_level_radon_limits hB hm hBm hBc hB0 hκ hκ8
79
+ γ G F hw hgrowth u hu t
80
+ have hex' : ∀ᵐ ω ∂P, ∃ ν : ℕ → Measure upperHalfPlane, (∀ j, (ν j).Regular) ∧
81
+ ∀ j (f : C_c(upperHalfPlane,ℝ)),
82
+ Tendsto (fun n => ∫ z, f z ∂convexLevelMeasure κ B γ G u s w n (t j) ω)
83
+ atTop (𝓝 (∫ z, f z ∂ν j)) := by
84
+ filter_upwards [hex] with ω hω
85
+ obtain ⟨ν,hν,hlim⟩ := hω
86
+ exact ⟨ν,fun j => (hν j).1,hlim⟩
87
+ obtain ⟨ν,hνm,hνr,hlim⟩ := exists_measurable_countable_radon_limits P
88
+ (fun n j ω => convexLevelMeasure κ B γ G u s w n (t j) ω)
89
+ (fun n j f => convexLevelMeasure_test_measurable hm hBc hκ hκ8 γ G F hw u hu s w hw₀ n (t j) f) hex'
90
+ refine ⟨s,w,ν,hw₀,hw₁,hνm,hνr,?_⟩
91
+ filter_upwards [hlim] with ω hω
92
+ refine ⟨hω,?_⟩
93
+ intro i j hij
94
+ let (k : ℕ) : IsFiniteMeasureOnCompacts (convexLevelMeasure κ B γ G u s w k (t i) ω) :=
95
+ convexLevelMeasure_finite_on_compacts hκ hκ8 γ G F ω (hBc ω) (hw ω) u s w k (t i)
96
+ let (k : ℕ) : IsFiniteMeasureOnCompacts (convexLevelMeasure κ B γ G u s w k (t j) ω) :=
97
+ convexLevelMeasure_finite_on_compacts hκ hκ8 γ G F ω (hBc ω) (hw ω) u s w k (t j)
98
+ let : (ν i ω).Regular := (hνr i ω).1
99
+ let : (ν j ω).Regular := (hνr j ω).1
100
+ exact radon_limits_mono _ _ (ν i ω) (ν j ω) (hω i) (hω j)
101
+ (fun k => convexLevelMeasure_mono κ B γ G u s w k ω hij)
102
+
103
+ end SLEExactGauge.Multipoint
104
+
105
+ end
106
+
107
+ end OAI
lean/OAI/Probability/SLE/Mass/LevelRemainderMeasure.lean ADDED
@@ -0,0 +1,113 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Mass.LevelApproximationKernel
2
+ import OAI.Probability.SLE.Mass.LevelMeanMeasure
3
+
4
+ namespace OAI
5
+
6
+ /-! The unreached part of a finite-level approximation, as a positive
7
+ measure. The conditional Green identity holds as a measure identity. -/
8
+
9
+ noncomputable section
10
+ open Set Filter MeasureTheory ProbabilityTheory Classical
11
+ open scoped NNReal ENNReal
12
+
13
+ namespace SLEExactGauge.Multipoint
14
+
15
+ def halfPlaneRemainderMeasure {Ω : Type*} (κ : ℝ) (B : ℝ≥0 → Ω → ℝ)
16
+ (γ : Ω → ℝ≥0 → ℂ) (G : Ω → ℝ≥0 → ℂ → ℂ)
17
+ (u : ℝ) (t : ℝ≥0) (ω : Ω) : Measure upperHalfPlane :=
18
+ (volume.withDensity (fun z => ENNReal.ofReal (levelRemainderGreen κ B γ G u t z ω))).comap Subtype.val
19
+
20
+ def halfPlaneCurrentMeasure {Ω : Type*} (κ : ℝ) (B : ℝ≥0 → Ω → ℝ)
21
+ (γ : Ω → ℝ≥0 → ℂ) (G : Ω → ℝ≥0 → ℂ → ℂ)
22
+ (u : ℝ) (t : ℝ≥0) (ω : Ω) : Measure upperHalfPlane :=
23
+ (volume.withDensity (fun z => ENNReal.ofReal (levelCurrentGreen κ B γ G u t z ω))).comap Subtype.val
24
+
25
+ lemma levelDensity_split {Ω : Type*} (κ : ℝ) (B : ℝ≥0 → Ω → ℝ)
26
+ (γ : Ω → ℝ≥0 → ℂ) (G : Ω → ℝ≥0 → ℂ → ℂ)
27
+ (u : ℝ) (t : ℝ≥0) (ω : Ω) (z : ℂ) :
28
+ levelApproximationDensity κ B γ G u ∞ ω z =
29
+ levelApproximationDensity κ B γ G u t ω z +
30
+ ENNReal.ofReal (levelRemainderGreen κ B γ G u t z ω) := by
31
+ unfold levelApproximationDensity levelRemainderGreen
32
+ by_cases h : radiusLevelTime (γ ω) (G ω) z u ≤ t
33
+ · simp only [le_top,ite_true,ite_eq_left h,ite_eq_right (not_lt.mpr h),
34
+ ENNReal.ofReal_zero,add_zero]
35
+ · simp only [le_top,ite_true,ite_eq_right h,ite_eq_left (lt_of_not_ge h),zero_add]
36
+
37
+ lemma halfPlaneRemainderMeasure_measurable
38
+ {Ω : Type*} [MeasurableSpace Ω] {B : ℝ≥0 → Ω → ℝ}
39
+ (hm : ∀ t, Measurable (B t)) (hBc : ∀ ω, Continuous (fun t => B t ω))
40
+ (κ u : ℝ) (hu : 0 ≤ u)
41
+ (γ : Ω → ℝ≥0 → ℂ) (G F : Ω → ℝ≥0 → ℂ → ℂ)
42
+ (hw : ∀ ω, IsCapacityTwoWitness (fun t => Real.sqrt κ * B t ω) (γ ω) (G ω) (F ω))
43
+ (t : ℝ≥0) : Measurable (halfPlaneRemainderMeasure κ B γ G u t) := by
44
+ apply Measure.measurable_of_measurable_coe
45
+ intro A hA
46
+ have hAI := (MeasurableEmbedding.subtype_coe isOpen_upperHalfPlane.measurableSet).measurableSet_image.mpr hA
47
+ simp only [halfPlaneRemainderMeasure,comap_subtype_coe_apply isOpen_upperHalfPlane.measurableSet,
48
+ withDensity_apply _ hAI]
49
+ exact (levelRemainderGreen_joint_measurable hm hBc κ u hu γ G F hw t).ennreal_ofReal.lintegral_prod_right'
50
+
51
+ lemma halfPlaneCurrentMeasure_measurable
52
+ {Ω : Type*} [MeasurableSpace Ω] {B : ℝ≥0 → Ω → ℝ}
53
+ (hBm : Measurable (Function.uncurry B)) (hBc : ∀ ω, Continuous (fun t => B t ω))
54
+ (κ u : ℝ) (hu : 0 ≤ u)
55
+ (γ : Ω → ℝ≥0 → ℂ) (G F : Ω → ℝ≥0 → ℂ → ℂ)
56
+ (hw : ∀ ω, IsCapacityTwoWitness (fun t => Real.sqrt κ * B t ω) (γ ω) (G ω) (F ω))
57
+ (t : ℝ≥0) : Measurable (halfPlaneCurrentMeasure κ B γ G u t) := by
58
+ apply Measure.measurable_of_measurable_coe
59
+ intro A hA
60
+ have hAI := (MeasurableEmbedding.subtype_coe isOpen_upperHalfPlane.measurableSet).measurableSet_image.mpr hA
61
+ simp only [halfPlaneCurrentMeasure,comap_subtype_coe_apply isOpen_upperHalfPlane.measurableSet,
62
+ withDensity_apply _ hAI]
63
+ exact (levelCurrentGreen_joint_measurable hBm hBc κ u hu γ G F hw t).ennreal_ofReal.lintegral_prod_right'
64
+
65
+ lemma halfPlaneLevelMeasure_split
66
+ {Ω : Type*} [MeasurableSpace Ω] {B : ℝ≥0 → Ω → ℝ}
67
+ (hm : ∀ t, Measurable (B t)) (hBc : ∀ ω, Continuous (fun t => B t ω))
68
+ (κ u : ℝ) (hu : 0 ≤ u)
69
+ (γ : Ω → ℝ≥0 → ℂ) (G F : Ω → ℝ≥0 → ℂ → ℂ)
70
+ (hw : ∀ ω, IsCapacityTwoWitness (fun t => Real.sqrt κ * B t ω) (γ ω) (G ω) (F ω))
71
+ (t : ℝ≥0) (ω : Ω) :
72
+ halfPlaneLevelMeasure κ B γ G u ∞ ω =
73
+ halfPlaneLevelMeasure κ B γ G u t ω + halfPlaneRemainderMeasure κ B γ G u t ω := by
74
+ apply Measure.ext
75
+ intro A hA
76
+ have hAI := (MeasurableEmbedding.subtype_coe isOpen_upperHalfPlane.measurableSet).measurableSet_image.mpr hA
77
+ simp only [Measure.add_apply,halfPlaneLevelMeasure,halfPlaneRemainderMeasure,levelApproximation,
78
+ comap_subtype_coe_apply isOpen_upperHalfPlane.measurableSet,withDensity_apply _ hAI]
79
+ simp_rw [levelDensity_split κ B γ G u t ω]
80
+ exact lintegral_add_left
81
+ (levelApproximationDensity_joint_measurable hm hBc κ u hu γ G F hw t).of_uncurry_left _
82
+
83
+ theorem halfPlaneRemainderMeasure_conditional_mean
84
+ {Ω : Type*} [MeasurableSpace Ω]
85
+ {P : Measure Ω} {B : ℝ≥0 → Ω → ℝ} (hB : IsBrownianReal B P)
86
+ (hBm : Measurable (Function.uncurry B))
87
+ (hBc : ∀ ω, Continuous (fun t => B t ω)) (hB0 : ∀ ω, B 0 ω = 0)
88
+ {κ : ℝ} (hκ : 0 < κ) (hκ8 : κ < 8)
89
+ (γ : Ω → ℝ≥0 → ��) (G F : Ω → ℝ≥0 → ℂ → ℂ)
90
+ (hw : ∀ ω, IsCapacityTwoWitness (fun t => Real.sqrt κ * B t ω) (γ ω) (G ω) (F ω))
91
+ (u : ℝ) (hu : 0 ≤ u) (t : ℝ≥0) (E : Set Ω)
92
+ (hE : MeasurableSet[Filtration.natural B (fun s =>
93
+ (hBm.comp (measurable_const.prodMk measurable_id) : Measurable (B s)).stronglyMeasurable) t] E) :
94
+ (P.restrict E).bind (halfPlaneRemainderMeasure κ B γ G u t) =
95
+ (P.restrict E).bind (halfPlaneCurrentMeasure κ B γ G u t) := by
96
+ let hm (s : ℝ≥0) : Measurable (B s) := hBm.comp (measurable_const.prodMk measurable_id)
97
+ apply Measure.ext
98
+ intro A hA
99
+ have hAI := (MeasurableEmbedding.subtype_coe isOpen_upperHalfPlane.measurableSet).measurableSet_image.mpr hA
100
+ have hAH : (Subtype.val : upperHalfPlane → ℂ) '' A ⊆ upperHalfPlane := by
101
+ rintro _ ⟨x,_,rfl⟩; exact x.property
102
+ rw [Measure.bind_apply hA (halfPlaneRemainderMeasure_measurable hm hBc κ u hu γ G F hw t).aemeasurable,
103
+ Measure.bind_apply hA (halfPlaneCurrentMeasure_measurable hBm hBc κ u hu γ G F hw t).aemeasurable]
104
+ simp only [halfPlaneRemainderMeasure,halfPlaneCurrentMeasure,
105
+ comap_subtype_coe_apply isOpen_upperHalfPlane.measurableSet,withDensity_apply _ hAI]
106
+ simpa only [one_mul] using levelRemainderGreen_spatial_kernel hB hBm hBc hB0 hκ hκ8 γ G F hw
107
+ u hu t _ hAI hAH (fun _ => 1) measurable_const E hE
108
+
109
+ end SLEExactGauge.Multipoint
110
+
111
+ end
112
+
113
+ end OAI
lean/OAI/Probability/SLE/Mass/LevelRemainderSupport.lean ADDED
@@ -0,0 +1,87 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Geometry.RandomKernelSupport
2
+ import OAI.Probability.SLE.Mass.GreenMeasureSupport
3
+ import OAI.Probability.SLE.Geometry.CountableRemainderKernels
4
+
5
+ namespace OAI
6
+
7
+ /-! The positive remaining mass in the actual countable Radon construction
8
+ is carried by the surviving Loewner domain. -/
9
+
10
+ noncomputable section
11
+ open Set Filter MeasureTheory ProbabilityTheory Classical
12
+ open scoped NNReal ENNReal Topology CompactlySupported
13
+
14
+ namespace SLEExactGauge.Multipoint
15
+
16
+ local instance : LocallyCompactSpace upperHalfPlane := isOpen_upperHalfPlane.locallyCompactSpace
17
+
18
+ lemma surviving_complement_past_measurable
19
+ {Ω : Type*} [mΩ : MeasurableSpace Ω] {B : ℝ≥0 → Ω → ℝ}
20
+ (hm : ∀ t, Measurable (B t)) (hBc : ∀ ω, Continuous (fun t => B t ω))
21
+ (κ : ℝ) (γ : Ω → ℝ≥0 → ℂ) (G F : Ω → ℝ≥0 → ℂ → ℂ)
22
+ (hw : ∀ ω, IsCapacityTwoWitness (fun t => Real.sqrt κ * B t ω) (γ ω) (G ω) (F ω))
23
+ (t : ℝ≥0) :
24
+ @MeasurableSet (Ω × upperHalfPlane)
25
+ ((Filtration.natural B (fun r => (hm r).stronglyMeasurable) t).prod inferInstance)
26
+ {p | (p.2 : ℂ) ∉ survivingDomain (γ p.1) t} := by
27
+ have hlive := (actual_spatial_past_kernels hm hBc κ γ G F hw t).2.2
28
+ let : MeasurableSpace Ω := Filtration.natural B (fun r => (hm r).stronglyMeasurable) t
29
+ let t0 : Iic t := ⟨t,by simp only [mem_Iic]; exact le_rfl⟩
30
+ have hmap : Measurable (fun p : Ω × upperHalfPlane =>
31
+ (t0,((p.2 : ℂ),p.1))) := by
32
+ apply Measurable.prodMk
33
+ · exact measurable_const
34
+ · exact ((measurable_subtype_coe : Measurable (fun z : upperHalfPlane => (z : ℂ))).comp
35
+ measurable_snd).prodMk measurable_fst
36
+ exact (hlive.preimage hmap).compl
37
+
38
+ theorem ae_remainder_carried_by_surviving
39
+ {Ω : Type*} [mΩ : MeasurableSpace Ω] {P : Measure Ω}
40
+ {B : ℝ≥0 → Ω → ℝ} (hB : IsBrownianReal B P)
41
+ (hBm : Measurable (Function.uncurry B)) (hBc : ∀ ω, Continuous (fun t => B t ω))
42
+ (hB0 : ∀ ω, B 0 ω = 0) {κ : ℝ} (hκ : 0 < κ) (hκ8 : κ < 8)
43
+ (γ : Ω → ℝ≥0 → ℂ) (G F : Ω → ℝ≥0 → ℂ → ℂ)
44
+ (hw : ∀ ω, IsCapacityTwoWitness (fun t => Real.sqrt κ * B t ω) (γ ω) (G ω) (F ω))
45
+ (t : ℝ≥0) (η : Ω → Measure upperHalfPlane) (hη : Measurable η)
46
+ (hηfin : ∀ ω, IsFiniteMeasureOnCompacts (η ω))
47
+ (hevent : ∀ E : Set Ω,
48
+ MeasurableSet[Filtration.natural B (fun r =>
49
+ (hBm.comp (measurable_const.prodMk measurable_id) : Measurable (B r)).stronglyMeasurable) t] E →
50
+ (P.restrict E).bind η = (P.restrict E).bind (halfPlaneGreenMeasure κ B γ G t)) :
51
+ ∀ᵐ ω ∂P, η ω {z : upperHalfPlane | (z : ℂ) ∉ survivingDomain (γ ω) t} = 0 := by
52
+ let D := localTestFamily upperHalfPlane
53
+ let ℱ := Filtration.natural B (fun r =>
54
+ (hBm.comp (measurable_const.prodMk measurable_id) : Measurable (B r)).stronglyMeasurable)
55
+ have hmean : P.bind η = P.bind (halfPlaneGreenMeasure κ B γ G t) := by
56
+ simpa only [Measure.restrict_univ] using hevent univ MeasurableSet.univ
57
+ let : IsFiniteMeasureOnCompacts (initialGreenMeasure κ) := initialGreenMeasure_finite_on_compacts κ
58
+ refine ae_avoids_random_set_of_conditional_kernel (ℱ t) (ℱ.le t) P η
59
+ (halfPlaneGreenMeasure κ B γ G t) hη
60
+ (halfPlaneGreenMeasure_measurable hBm hBc κ γ G F hw t)
61
+ D.compactSet (fun n => (D.isCompact n).measurableSet) ?_ ?_ ?_ ?_ hevent
62
+ {p | (p.2 : ℂ) ∉ survivingDomain (γ p.1) t} ?_ ?_
63
+ · intro z
64
+ obtain ⟨n,hn⟩ := D.exhaustive {z} isCompact_singleton
65
+ exact ⟨n,hn (mem_singleton z)⟩
66
+ · intro n ω
67
+ let := hηfin ω
68
+ exact (D.isCompact n).measure_lt_top
69
+ · intro n
70
+ exact ae_halfPlaneGreenMeasure_compact_finite hB hBm hBc hB0 hκ hκ8 γ G F hw t
71
+ _ (D.isCompact n)
72
+ · intro n
73
+ rw [hmean]
74
+ have hb := halfPlaneGreenMeasure_mean_le hB hBm hBc hB0 hκ hκ8 γ G F hw t univ
75
+ (D.compactSet n)
76
+ rw [Measure.restrict_univ] at hb
77
+ exact lt_of_le_of_lt hb (D.isCompact n).measure_lt_top
78
+ · exact surviving_complement_past_measurable
79
+ (fun r => hBm.comp (measurable_const.prodMk measurable_id)) hBc κ γ G F hw t
80
+ · intro ω
81
+ exact halfPlaneGreenMeasure_off_surviving ω (hw ω) t
82
+
83
+ end SLEExactGauge.Multipoint
84
+
85
+ end
86
+
87
+ end OAI
lean/OAI/Probability/SLE/Mass/LevelStoppingConvex.lean ADDED
@@ -0,0 +1,128 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Mass.LevelStoppingTests
2
+
3
+ namespace OAI
4
+
5
+ /-! The actual common convex tails preserve the conditional decomposition
6
+ at every Brownian stopping time, including infinite stops. -/
7
+
8
+ noncomputable section
9
+ open Set Filter MeasureTheory ProbabilityTheory Classical
10
+ open scoped NNReal ENNReal Topology CompactlySupported
11
+
12
+ namespace SLEExactGauge.Multipoint
13
+
14
+ local instance : LocallyCompactSpace upperHalfPlane := isOpen_upperHalfPlane.locallyCompactSpace
15
+
16
+ def convexStoppingCurrentMean {Ω : Type*} [MeasurableSpace Ω] (P : Measure Ω)
17
+ (κ : ℝ) (B : ℝ≥0 → Ω → ℝ) (γ : Ω → ℝ≥0 → ℂ) (G : Ω → ℝ≥0 → ℂ → ℂ)
18
+ (u : ℕ → ℝ) (s : ℕ → Finset ℕ) (w : ℕ → ℕ → ℝ) (n : ℕ) (S : Ω → ℝ≥0∞) :
19
+ Measure upperHalfPlane :=
20
+ ∑ i ∈ s n, ENNReal.ofReal (w n i) • P.bind (halfPlaneStoppingCurrentMeasure κ B γ G (u (n+i)) S)
21
+
22
+ lemma convexLevelMeasure_random_time_measurable
23
+ {Ω : Type*} [MeasurableSpace Ω] {B : ℝ≥0 → Ω → ℝ}
24
+ (hm : ∀ t, Measurable (B t)) (hc : ∀ ω, Continuous (fun t => B t ω))
25
+ (κ : ℝ) (γ : Ω → ℝ≥0 → ℂ) (G F : Ω → ℝ≥0 → ℂ → ℂ)
26
+ (hw : ∀ ω, IsCapacityTwoWitness (fun t => Real.sqrt κ * B t ω) (γ ω) (G ω) (F ω))
27
+ (u : ℕ → ℝ) (hu : ∀ n, 0 ≤ u n) (s : ℕ → Finset ℕ) (w : ℕ → ℕ → ℝ)
28
+ (n : ℕ) (S : Ω → ℝ≥0∞) (hS : Measurable S) :
29
+ Measurable (fun ω => convexLevelMeasure κ B γ G u s w n (S ω) ω) := by
30
+ apply Measure.measurable_of_measurable_coe
31
+ intro A hA
32
+ simp only [convexLevelMeasure,Measure.finsetSum_apply,Measure.smul_apply,smul_eq_mul]
33
+ apply Finset.measurable_sum
34
+ intro i _
35
+ exact measurable_const.mul ((Measure.measurable_coe hA).comp
36
+ (halfPlaneLevelMeasure_random_time_measurable hm hc κ (u (n+i)) (hu _) γ G F hw S hS))
37
+
38
+ lemma convexLevelMeasure_stopping_conditional_split
39
+ {Ω : Type*} [MeasurableSpace Ω] {P : Measure Ω}
40
+ {B : ℝ≥0 → Ω → ℝ} (hB : IsBrownianReal B P)
41
+ (hBm : Measurable (Function.uncurry B)) (hc : ∀ ω, Continuous (fun t => B t ω))
42
+ (hB0 : ∀ ω, B 0 ω = 0) {κ : ℝ} (hκ : 0 < κ) (hκ8 : κ < 8)
43
+ (γ : Ω → ℝ≥0 → ℂ) (G F : Ω → ℝ≥0 → ℂ → ℂ)
44
+ (hw : ∀ ω, IsCapacityTwoWitness (fun t => Real.sqrt κ * B t ω) (γ ω) (G ω) (F ω))
45
+ (u : ℕ → ℝ) (hu : ∀ n, 0 ≤ u n) (s : ℕ → Finset ℕ) (w : ℕ → ℕ → ℝ)
46
+ (n : ℕ) (S : Ω → WithTop ℝ≥0)
47
+ (hS : IsStoppingTime (Filtration.natural B (fun r =>
48
+ (hBm.comp (measurable_const.prodMk measurable_id) : Measurable (B r)).stronglyMeasurable)) S)
49
+ (E : Set Ω) (hE : MeasurableSet[hS.measurableSpace] E) :
50
+ (P.restrict E).bind (convexLevelMeasure κ B γ G u s w n ∞) =
51
+ (P.restrict E).bind (fun ω => convexLevelMeasure κ B γ G u s w n (S ω) ω) +
52
+ convexStoppingCurrentMean (P.restrict E) κ B γ G u s w n S := by
53
+ let hm (r : ℝ≥0) : Measurable (B r) := hBm.comp (measurable_const.prodMk measurable_id)
54
+ unfold convexLevelMeasure convexStoppingCurrentMean
55
+ rw [bind_finset_smul _ _ _ (fun _ => ENNReal.ofReal_ne_top) _
56
+ (fun i => halfPlaneLevelMeasure_measurable hm hc κ (u (n+i)) (hu _) γ G F hw ∞),
57
+ bind_finset_smul _ _ _ (fun _ => ENNReal.ofReal_ne_top) _
58
+ (fun i => halfPlaneLevelMeasure_random_time_measurable hm hc κ (u (n+i)) (hu _)
59
+ γ G F hw S hS.measurable')]
60
+ simp_rw [halfPlaneLevelMeasure_stopping_conditional_split hB hBm hc hB0 hκ hκ8 γ G F hw
61
+ _ (hu _) S hS E hE,smul_add,Finset.sum_add_distrib]
62
+
63
+ lemma convexStoppingCurrentMean_le
64
+ {Ω : Type*} [MeasurableSpace Ω] {P : Measure Ω}
65
+ {B : ℝ≥0 → Ω → ℝ} (hB : IsBrownianReal B P)
66
+ (hBm : Measurable (Function.uncurry B)) (hc : ∀ ω, Continuous (fun t => B t ω))
67
+ (hB0 : ∀ ω, B 0 ω = 0) {κ : ℝ} (hκ : 0 < κ) (hκ8 : κ < 8)
68
+ (γ : Ω → ℝ≥0 → ℂ) (G F : Ω → ℝ≥0 → ℂ → ℂ)
69
+ (hw : ∀ ω, IsCapacityTwoWitness (fun t => Real.sqrt κ * B t ω) (γ ω) (G ω) (F ω))
70
+ (u : ℕ → ℝ) (hu : ∀ n, 0 ≤ u n) (s : ℕ → Finset ℕ) (w : ℕ → ℕ → ℝ)
71
+ (hw₀ : ∀ n i, i ∈ s n → 0 ≤ w n i) (hw₁ : ∀ n, ∑ i ∈ s n, w n i = 1)
72
+ (n : ℕ) (S : Ω → WithTop ℝ≥0)
73
+ (hS : IsStoppingTime (Filtration.natural B (fun r =>
74
+ (hBm.comp (measurable_const.prodMk measurable_id) : Measurable (B r)).stronglyMeasurable)) S)
75
+ (E : Set Ω) :
76
+ convexStoppingCurrentMean (P.restrict E) κ B γ G u s w n S ≤ initialGreenMeasure κ := by
77
+ apply Measure.le_iff.mpr
78
+ intro A _
79
+ simp only [convexStoppingCurrentMean,Measure.finsetSum_apply,Measure.smul_apply,smul_eq_mul]
80
+ calc
81
+ _ ≤ ∑ i ∈ s n, ENNReal.ofReal (w n i) * initialGreenMeasure κ A :=
82
+ Finset.sum_le_sum (fun i _ => mul_le_mul' le_rfl
83
+ (halfPlaneStoppingCurrentMeasure_mean_le hB hBm hc hB0 hκ hκ8 γ G F hw
84
+ (u (n+i)) (hu _) S hS E A))
85
+ _ = _ := by
86
+ rw [← Finset.sum_mul,← ENNReal.ofReal_sum_of_nonneg (hw₀ n),hw₁ n,ENNReal.ofReal_one,one_mul]
87
+
88
+ theorem convexStoppingCurrentMean_test_tendsto
89
+ {Ω : Type*} [MeasurableSpace Ω] {P : Measure Ω}
90
+ {B : ℝ≥0 → Ω → ℝ} (hB : IsBrownianReal B P)
91
+ (hBm : Measurable (Function.uncurry B)) (hc : ∀ ω, Continuous (fun t => B t ω))
92
+ (hB0 : ∀ ω, B 0 ω = 0) {κ : ℝ} (hκ : 0 < κ) (hκ8 : κ < 8)
93
+ (γ : Ω → ℝ≥0 → ℂ) (G F : Ω → ℝ≥0 → ℂ → ℂ)
94
+ (hw : ∀ ω, IsCapacityTwoWitness (fun t => Real.sqrt κ * B t ω) (γ ω) (G ω) (F ω))
95
+ (u : ℕ → ℝ) (hu : ∀ n, 0 ≤ u n) (hmono : Monotone u) (hlim : Tendsto u atTop atTop)
96
+ (s : ℕ → Finset ℕ) (w : ℕ → ℕ → ℝ)
97
+ (hw₀ : ∀ n i, i ∈ s n → 0 ≤ w n i) (hw₁ : ∀ n, ∑ i ∈ s n, w n i = 1)
98
+ (S : Ω → WithTop ℝ≥0)
99
+ (hS : IsStoppingTime (Filtration.natural B (fun r =>
100
+ (hBm.comp (measurable_const.prodMk measurable_id) : Measurable (B r)).stronglyMeasurable)) S)
101
+ (E : Set Ω) (f : C_c(upperHalfPlane,ℝ)) :
102
+ Tendsto (fun n => ∫ z, f z ∂convexStoppingCurrentMean (P.restrict E) κ B γ G u s w n S)
103
+ atTop (𝓝 (∫ z, f z ∂(P.restrict E).bind (halfPlaneStoppingGreenMeasure κ B γ G S))) := by
104
+ let ρ := initialGreenMeasure κ
105
+ let : IsFiniteMeasureOnCompacts ρ := initialGreenMeasure_finite_on_compacts κ
106
+ let μ (j : ℕ) := (P.restrict E).bind (halfPlaneStoppingCurrentMeasure κ B γ G (u j) S)
107
+ have hμ (j : ℕ) : μ j ≤ ρ :=
108
+ halfPlaneStoppingCurrentMeasure_mean_le hB hBm hc hB0 hκ hκ8 γ G F hw (u j) (hu j) S hS E
109
+ have hfi (j : ℕ) : Integrable f (μ j) := f.integrable.mono_measure (hμ j)
110
+ have he (n : ℕ) : (∫ z, f z ∂convexStoppingCurrentMean (P.restrict E) κ B γ G u s w n S) =
111
+ ∑ i ∈ s n, w n i * (∫ z, f z ∂μ (n+i)) := by
112
+ have hi (i : ℕ) : Integrable f (ENNReal.ofReal (w n i) • μ (n+i)) :=
113
+ (hfi (n+i)).smul_measure ENNReal.ofReal_ne_top
114
+ change (∫ z, f z ∂∑ i ∈ s n, ENNReal.ofReal (w n i) • μ (n+i)) = _
115
+ rw [integral_finsetSum_measure (fun i _ => hi i)]
116
+ apply Finset.sum_congr rfl
117
+ intro i his
118
+ rw [integral_smul_measure,ENNReal.toReal_ofReal (hw₀ n i his),smul_eq_mul]
119
+ simp only [he]
120
+ exact real_convex_tail_tendsto (fun j => ∫ z, f z ∂μ j)
121
+ (halfPlaneStoppingCurrentMeasure_mean_test_tendsto hB hBm hc hB0 hκ hκ8 γ G F hw
122
+ u hu hmono hlim S hS E f) s w hw₀ hw₁
123
+
124
+ end SLEExactGauge.Multipoint
125
+
126
+ end
127
+
128
+ end OAI
lean/OAI/Probability/SLE/Mass/LevelStoppingGreenLimit.lean ADDED
@@ -0,0 +1,131 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Mass.LevelStoppingSpatialKernel
2
+ import OAI.Probability.SLE.Mass.LevelGreenLimit
3
+
4
+ namespace OAI
5
+
6
+ /-! Increasing finite radius levels recover the Green kernel killed at an
7
+ arbitrary stopping time. Its expectation is bounded by the initial Green
8
+ function, also when the stopping time may be infinite. -/
9
+
10
+ noncomputable section
11
+ open Set Filter MeasureTheory ProbabilityTheory Classical
12
+ open scoped Topology NNReal ENNReal
13
+
14
+ namespace SLEExactGauge.Multipoint
15
+
16
+ def stoppingGreen {Ω : Type*} (κ : ℝ) (B : ℝ≥0 → Ω → ℝ)
17
+ (γ : Ω → ℝ≥0 → ℂ) (G : Ω → ℝ≥0 → ℂ → ℂ)
18
+ (S : Ω → ℝ≥0∞) (z : ℂ) (ω : Ω) : ℝ :=
19
+ if S ω < ∞ then greenDensity κ (fun s => Real.sqrt κ * B s ω)
20
+ (γ ω) (G ω) (S ω).toNNReal z else 0
21
+
22
+ lemma levelStoppingCurrentGreen_mono
23
+ {Ω : Type*} {B : ℝ≥0 → Ω → ℝ} {κ : ℝ}
24
+ {γ : Ω → ℝ≥0 → ℂ} {G F : Ω → ℝ≥0 → ℂ → ℂ}
25
+ (ω : Ω) (hc : Continuous (fun s => B s ω))
26
+ (hw : IsCapacityTwoWitness (fun s => Real.sqrt κ * B s ω) (γ ω) (G ω) (F ω))
27
+ (z : ℂ) (S : Ω → ℝ≥0∞) {u v : ℝ} (hu : 0 ≤ u) (huv : u ≤ v) :
28
+ levelStoppingCurrentGreen κ B γ G u S z ω ≤ levelStoppingCurrentGreen κ B γ G v S z ω := by
29
+ have hτ := radiusLevelTime_mono (hc.const_mul _) hw z hu huv
30
+ unfold levelStoppingCurrentGreen
31
+ split_ifs with h₁ h₂
32
+ · exact le_rfl
33
+ · exact False.elim (h₂ (h₁.trans_le hτ))
34
+ · exact greenDensity_nonneg hw κ _ z
35
+ · exact le_rfl
36
+
37
+ lemma levelStoppingCurrentGreen_eventually_eq
38
+ {Ω : Type*} {B : ℝ≥0 → Ω → ℝ} {κ : ℝ}
39
+ {γ : Ω → ℝ≥0 → ℂ} {G F : Ω → ℝ≥0 → ℂ → ℂ}
40
+ (ω : Ω) (hc : Continuous (fun s => B s ω))
41
+ (hw : IsCapacityTwoWitness (fun s => Real.sqrt κ * B s ω) (γ ω) (G ω) (F ω))
42
+ (z : ℂ) (S : Ω → ℝ≥0∞) (u : ℕ → ℝ) (hu : ∀ n, 0 ≤ u n)
43
+ (hlim : Tendsto u atTop atTop) :
44
+ ∀ᶠ n in atTop, levelStoppingCurrentGreen κ B γ G (u n) S z ω = stoppingGreen κ B γ G S z ω := by
45
+ by_cases hfin : S ω < ∞
46
+ · have hcoe : ((S ω).toNNReal : ℝ≥0∞) = S ω := ENNReal.coe_toNNReal hfin.ne
47
+ filter_upwards [levelCurrentGreen_eventually_eq ω hc hw z (S ω).toNNReal u hu hlim] with n hn
48
+ simpa only [levelCurrentGreen,levelStoppingCurrentGreen,stoppingGreen,hcoe,ite_eq_left hfin] using hn
49
+ · have htop : S ω = ∞ := top_le_iff.mp (le_of_not_gt hfin)
50
+ filter_upwards [] with n
51
+ simp [levelStoppingCurrentGreen,stoppingGreen,htop]
52
+
53
+ theorem levelStoppingCurrentGreen_mean_le
54
+ {Ω : Type*} [mΩ : MeasurableSpace Ω] {P : Measure Ω}
55
+ {B : ℝ≥0 → Ω → ℝ} (hB : IsBrownianReal B P)
56
+ (hBm : Measurable (Function.uncurry B))
57
+ (hc : ∀ ω, Continuous (fun t => B t ω)) (hB0 : ∀ ω, B 0 ω = 0)
58
+ {κ : ℝ} (hκ : 0 < κ) (hκ8 : κ < 8)
59
+ (γ : Ω → ℝ≥0 → ℂ) (G F : Ω → ℝ≥0 → ℂ → ℂ)
60
+ (hw : ∀ ω, IsCapacityTwoWitness (fun s => Real.sqrt κ * B s ω) (γ ω) (G ω) (F ω))
61
+ (z : ℂ) (hz : z ∈ upperHalfPlane) (u : ℝ) (hu : 0 ≤ u)
62
+ (S : Ω → WithTop ℝ≥0)
63
+ (hS : IsStoppingTime (Filtration.natural B (fun s =>
64
+ (hBm.comp (measurable_const.prodMk measurable_id) : Measurable (B s)).stronglyMeasurable)) S) :
65
+ (∫⁻ ω, ENNReal.ofReal (levelStoppingCurrentGreen κ B γ G u S z ω) ∂P) ≤
66
+ ENNReal.ofReal (initialGreen κ z) := by
67
+ let : IsProbabilityMeasure P := hB.isGaussianProcess.isProbabilityMeasure
68
+ have he := levelStoppingRemainderGreen_setLIntegral hB hBm hc hB0 hκ hκ8
69
+ γ G F hw z hz u hu S hS univ MeasurableSet.univ
70
+ simp only [Measure.restrict_univ] at he
71
+ rw [← he]
72
+ calc
73
+ _ ≤ ∫⁻ ω, ENNReal.ofReal (stoppedGreen κ (fun s => Real.sqrt κ * B s ω)
74
+ (γ ω) (G ω) z u) ∂P := by
75
+ apply lintegral_mono
76
+ intro ω
77
+ unfold levelStoppingRemainderGreen
78
+ dsimp only
79
+ split_ifs
80
+ · exact le_rfl
81
+ · simp only [ENNReal.ofReal_zero]
82
+ exact bot_le
83
+ _ = _ := by
84
+ obtain ⟨hi,he⟩ := finite_stopped_green_regular hB hBm hc hB0 κ hκ hκ8 γ G F
85
+ (ae_of_all _ hw) z hz u hu
86
+ rw [← ofReal_integral_eq_lintegral_ofReal hi
87
+ (ae_of_all _ (fun ω => stoppedGreen_nonneg (hw ω) κ z u)),he]
88
+
89
+ theorem stoppingGreen_mean_le
90
+ {Ω : Type*} [mΩ : MeasurableSpace Ω] {P : Measure Ω}
91
+ {B : ℝ≥0 → Ω → ℝ} (hB : IsBrownianReal B P)
92
+ (hBm : Measurable (Function.uncurry B))
93
+ (hc : ∀ ω, Continuous (fun t => B t ω)) (hB0 : ∀ ω, B 0 ω = 0)
94
+ {κ : ℝ} (hκ : 0 < κ) (hκ8 : κ < 8)
95
+ (γ : Ω → ℝ≥0 → ℂ) (G F : Ω → ℝ≥0 → ℂ → ℂ)
96
+ (hw : ∀ ω, IsCapacityTwoWitness (fun s => Real.sqrt κ * B s ω) (γ ω) (G ω) (F ω))
97
+ (z : ℂ) (hz : z ∈ upperHalfPlane) (S : Ω → WithTop ℝ≥0)
98
+ (hS : IsStoppingTime (Filtration.natural B (fun s =>
99
+ (hBm.comp (measurable_const.prodMk measurable_id) : Measurable (B s)).stronglyMeasurable)) S) :
100
+ (∫⁻ ω, ENNReal.ofReal (stoppingGreen κ B γ G S z ω) ∂P) ≤
101
+ ENNReal.ofReal (initialGreen κ z) := by
102
+ have hm (n : ℕ) : Measurable (fun ω => ENNReal.ofReal
103
+ (levelStoppingCurrentGreen κ B γ G n S z ω)) := by
104
+ have hj := (levelStoppingCurrentGreen_joint_measurable hBm hc κ n (Nat.cast_nonneg n)
105
+ γ G F hw S hS.measurable').ennreal_ofReal
106
+ have hh := hj.comp (measurable_id.prodMk (measurable_const (a := z)))
107
+ simpa only [Function.comp_def,id_eq] using hh
108
+ have hmono : ∀ᵐ ω ∂P, Monotone (fun n : ℕ => ENNReal.ofReal
109
+ (levelStoppingCurrentGreen κ B γ G n S z ω)) := by
110
+ filter_upwards [] with ω
111
+ intro n k hnk
112
+ exact ENNReal.ofReal_le_ofReal (levelStoppingCurrentGreen_mono ω (hc ω) (hw ω)
113
+ z S (Nat.cast_nonneg n) (Nat.cast_le.mpr hnk))
114
+ have hlim : ∀ᵐ ω ∂P, Tendsto (fun n : ℕ => ENNReal.ofReal
115
+ (levelStoppingCurrentGreen κ B γ G n S z ω)) atTop
116
+ (𝓝 (ENNReal.ofReal (stoppingGreen κ B γ G S z ω))) := by
117
+ filter_upwards [] with ω
118
+ apply tendsto_const_nhds.congr'
119
+ exact (levelStoppingCurrentGreen_eventually_eq ω (hc ω) (hw ω) z S
120
+ (fun n : ℕ => (n:ℝ)) (fun n => Nat.cast_nonneg n) tendsto_natCast_atTop_atTop).mono
121
+ (fun _ he => congrArg ENNReal.ofReal he.symm)
122
+ exact le_of_tendsto (lintegral_tendsto_of_tendsto_of_monotone
123
+ (fun n => (hm n).aemeasurable) hmono hlim)
124
+ (Eventually.of_forall (fun n => levelStoppingCurrentGreen_mean_le hB hBm hc hB0 hκ hκ8
125
+ γ G F hw z hz n (Nat.cast_nonneg n) S hS))
126
+
127
+ end SLEExactGauge.Multipoint
128
+
129
+ end
130
+
131
+ end OAI
lean/OAI/Probability/SLE/Mass/LevelStoppingKernel.lean ADDED
@@ -0,0 +1,230 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Mass.LevelApproximationKernel
2
+ import OAI.Probability.SLE.Loewner.ActualRadiusStopsRegular
3
+ import OAI.Probability.SLE.Gauge.ExtendedExperimentStop
4
+
5
+ namespace OAI
6
+
7
+ /-! The finite-level remaining Green kernel at any Brownian stopping
8
+ time. Both sides vanish at an infinite stopping time. Finite cutoffs use
9
+ the existing optional identity for the stopped Green martingale. -/
10
+
11
+ noncomputable section
12
+ open Set Filter MeasureTheory ProbabilityTheory Classical
13
+ open scoped Topology NNReal ENNReal
14
+
15
+ namespace SLEExactGauge.Multipoint
16
+
17
+ def levelStoppingRemainderGreen {Ω : Type*} (κ : ℝ) (B : ℝ≥0 → Ω → ℝ)
18
+ (γ : Ω → ℝ≥0 → ℂ) (G : Ω → ℝ≥0 → ℂ → ℂ)
19
+ (u : ℝ) (S : Ω → ℝ≥0∞) (z : ℂ) (ω : Ω) : ℝ :=
20
+ if S ω < radiusLevelTime (γ ω) (G ω) z u then
21
+ stoppedGreen κ (fun s => Real.sqrt κ * B s ω) (γ ω) (G ω) z u else 0
22
+
23
+ def levelStoppingCurrentGreen {Ω : Type*} (κ : ℝ) (B : ℝ≥0 → Ω → ℝ)
24
+ (γ : Ω → ℝ≥0 → ℂ) (G : Ω → ℝ≥0 → ℂ → ℂ)
25
+ (u : ℝ) (S : Ω → ℝ≥0∞) (z : ℂ) (ω : Ω) : ℝ :=
26
+ if S ω < radiusLevelTime (γ ω) (G ω) z u then
27
+ greenDensity κ (fun s => Real.sqrt κ * B s ω) (γ ω) (G ω) (S ω).toNNReal z else 0
28
+
29
+ lemma levelStoppingRemainderGreen_nonneg
30
+ {Ω : Type*} (κ : ℝ) (B : ℝ≥0 → Ω → ℝ)
31
+ (γ : Ω → ℝ≥0 → ℂ) (G F : Ω → ℝ≥0 → ℂ → ℂ)
32
+ (hw : ∀ ω, IsCapacityTwoWitness (fun s => Real.sqrt κ * B s ω) (γ ω) (G ω) (F ω))
33
+ (u : ℝ) (S : Ω → ℝ≥0∞) (z : ℂ) (ω : Ω) :
34
+ 0 ≤ levelStoppingRemainderGreen κ B γ G u S z ω := by
35
+ unfold levelStoppingRemainderGreen
36
+ split_ifs
37
+ · exact stoppedGreen_nonneg (hw ω) κ z u
38
+ · exact le_rfl
39
+
40
+ lemma levelStoppingCurrentGreen_nonneg
41
+ {Ω : Type*} (κ : ℝ) (B : ℝ≥0 → Ω → ℝ)
42
+ (γ : Ω → ℝ≥0 → ℂ) (G F : Ω → ℝ≥0 → ℂ → ℂ)
43
+ (hw : ∀ ω, IsCapacityTwoWitness (fun s => Real.sqrt κ * B s ω) (γ ω) (G ω) (F ω))
44
+ (u : ℝ) (S : Ω → ℝ≥0∞) (z : ℂ) (ω : Ω) :
45
+ 0 ≤ levelStoppingCurrentGreen κ B γ G u S z ω := by
46
+ unfold levelStoppingCurrentGreen
47
+ split_ifs
48
+ · exact greenDensity_nonneg (hw ω) κ _ z
49
+ · exact le_rfl
50
+
51
+ theorem levelStoppingRemainderGreen_finite_condExp
52
+ {Ω : Type*} [mΩ : MeasurableSpace Ω] {P : Measure Ω}
53
+ {B : ℝ≥0 → Ω → ℝ} (hB : IsBrownianReal B P)
54
+ (hBm : Measurable (Function.uncurry B))
55
+ (hc : ∀ ω, Continuous (fun t => B t ω)) (hB0 : ∀ ω, B 0 ω = 0)
56
+ {κ : ℝ} (hκ : 0 < κ) (hκ8 : κ < 8)
57
+ (γ : Ω → ℝ≥0 → ℂ) (G F : Ω → ℝ≥0 → ℂ → ℂ)
58
+ (hw : ∀ ω, IsCapacityTwoWitness (fun s => Real.sqrt κ * B s ω) (γ ω) (G ω) (F ω))
59
+ (z : ℂ) (hz : z ∈ upperHalfPlane) (u : ℝ) (hu : 0 ≤ u)
60
+ (σ : Ω → ℝ≥0)
61
+ (hσ : IsStoppingTime (Filtration.natural B (fun s =>
62
+ (hBm.comp (measurable_const.prodMk measurable_id) : Measurable (B s)).stronglyMeasurable))
63
+ (fun ω => (σ ω : WithTop ℝ≥0))) :
64
+ Integrable (levelStoppingRemainderGreen κ B γ G u (fun ω => σ ω) z) P ∧
65
+ Integrable (levelStoppingCurrentGreen κ B γ G u (fun ω => σ ω) z) P ∧
66
+ P[levelStoppingRemainderGreen κ B γ G u (fun ω => σ ω) z | hσ.measurableSpace] =ᵐ[P]
67
+ levelStoppingCurrentGreen κ B γ G u (fun ω => σ ω) z := by
68
+ let : IsProbabilityMeasure P := hB.isGaussianProcess.isProbabilityMeasure
69
+ let hm (s : ℝ≥0) : Measurable (B s) := hBm.comp (measurable_const.prodMk measurable_id)
70
+ obtain ⟨M,Z,_,hZi,_,_,_,hStop,heq,_⟩ := exists_physical_green_stopping_regular
71
+ hB hBm hc hB0 κ hκ hκ8 γ G F (ae_of_all _ hw) z hz u hu
72
+ have hτ := actual_radiusLevelTime_stopping hB hm hBm hc hB0 κ hκ hκ8 γ G F hw z hz u hu
73
+ let A : Set Ω := {ω | (σ ω : ℝ≥0∞) < radiusLevelTime (γ ω) (G ω) z u}
74
+ have hA : MeasurableSet[hσ.measurableSpace] A := by
75
+ have he : A = {ω | radiusLevelTime (γ ω) (G ω) z u ≤ (σ ω : WithTop ℝ≥0)}ᶜ := by
76
+ ext ω
77
+ change (σ ω : ℝ≥0∞) < radiusLevelTime (γ ω) (G ω) z u ↔
78
+ ¬ radiusLevelTime (γ ω) (G ω) z u ≤ (σ ω : ℝ≥0∞)
79
+ exact lt_iff_not_ge
80
+ rw [he]
81
+ exact (hτ.measurableSet_stopping_time_le hσ).compl
82
+ have hAg : MeasurableSet A := hσ.measurableSpace_le _ hA
83
+ have hR : levelStoppingRemainderGreen κ B γ G u (fun ω => σ ω) z =ᵐ[P] A.indicator Z := by
84
+ filter_upwards [heq] with ω he
85
+ by_cases ha : ω ∈ A
86
+ · have ht : (σ ω : ℝ≥0∞) < radiusLevelTime (γ ω) (G ω) z u := ha
87
+ rw [levelStoppingRemainderGreen,ite_eq_left ht,indicator_of_mem ha,he.2]
88
+ · have ht : ¬ (σ ω : ℝ≥0∞) < radiusLevelTime (γ ω) (G ω) z u := ha
89
+ rw [levelStoppingRemainderGreen,ite_eq_right ht,indicator_of_notMem ha]
90
+ have hC : levelStoppingCurrentGreen κ B γ G u (fun ω => σ ω) z =ᵐ[P]
91
+ A.indicator (fun ω => M (σ ω) ω) := by
92
+ filter_upwards [heq] with ω he
93
+ by_cases ha : ω ∈ A
94
+ · have ht : (σ ω : ℝ≥0∞) < radiusLevelTime (γ ω) (G ω) z u := ha
95
+ rw [levelStoppingCurrentGreen,ite_eq_left ht,indicator_of_mem ha,ENNReal.toNNReal_coe,
96
+ he.1 (σ ω),physicalStoppedGreen,ite_eq_right (not_le.mpr ht)]
97
+ · have ht : ¬ (σ ω : ℝ≥0∞) < radiusLevelTime (γ ω) (G ω) z u := ha
98
+ rw [levelStoppingCurrentGreen,ite_eq_right ht,indicator_of_notMem ha]
99
+ have hMi : Integrable (fun ω => M (σ ω) ω) P :=
100
+ integrable_condExp.congr (hStop σ hσ).symm
101
+ refine ⟨(hZi.indicator hAg).congr hR.symm,(hMi.indicator hAg).congr hC.symm,?_⟩
102
+ apply (condExp_congr_ae hR).trans
103
+ apply (condExp_indicator hZi hA).trans
104
+ apply EventuallyEq.trans _ hC.symm
105
+ filter_upwards [hStop σ hσ] with ω he
106
+ by_cases ha : ω ∈ A
107
+ · simpa only [indicator_of_mem ha] using he.symm
108
+ · simp only [indicator_of_notMem ha]
109
+
110
+ theorem levelStoppingRemainderGreen_finite_setLIntegral
111
+ {Ω : Type*} [mΩ : MeasurableSpace Ω] {P : Measure Ω}
112
+ {B : ℝ≥0 → Ω → ℝ} (hB : IsBrownianReal B P)
113
+ (hBm : Measurable (Function.uncurry B))
114
+ (hc : ∀ ω, Continuous (fun t => B t ω)) (hB0 : ∀ ω, B 0 ω = 0)
115
+ {κ : ℝ} (hκ : 0 < κ) (hκ8 : κ < 8)
116
+ (γ : Ω → ℝ≥0 → ℂ) (G F : Ω → ℝ≥0 → ℂ → ℂ)
117
+ (hw : ∀ ω, IsCapacityTwoWitness (fun s => Real.sqrt κ * B s ω) (γ ω) (G ω) (F ω))
118
+ (z : ℂ) (hz : z ∈ upperHalfPlane) (u : ℝ) (hu : 0 ≤ u)
119
+ (σ : Ω → ℝ≥0)
120
+ (hσ : IsStoppingTime (Filtration.natural B (fun s =>
121
+ (hBm.comp (measurable_const.prodMk measurable_id) : Measurable (B s)).stronglyMeasurable))
122
+ (fun ω => (σ ω : WithTop ℝ≥0)))
123
+ (A : Set Ω) (hA : MeasurableSet[hσ.measurableSpace] A) :
124
+ (∫⁻ ω in A, ENNReal.ofReal (levelStoppingRemainderGreen κ B γ G u (fun ω => σ ω) z ω) ∂P) =
125
+ ∫⁻ ω in A, ENNReal.ofReal (levelStoppingCurrentGreen κ B γ G u (fun ω => σ ω) z ω) ∂P := by
126
+ let : IsProbabilityMeasure P := hB.isGaussianProcess.isProbabilityMeasure
127
+ obtain ⟨hR,hC,he⟩ := levelStoppingRemainderGreen_finite_condExp hB hBm hc hB0 hκ hκ8
128
+ γ G F hw z hz u hu σ hσ
129
+ have hRn : ∀ᵐ ω ∂P.restrict A, 0 ≤ levelStoppingRemainderGreen κ B γ G u (fun ω => σ ω) z ω :=
130
+ ae_of_all _ (levelStoppingRemainderGreen_nonneg κ B γ G F hw u _ z)
131
+ have hCn : ∀ᵐ ω ∂P.restrict A, 0 ≤ levelStoppingCurrentGreen κ B γ G u (fun ω => σ ω) z ω :=
132
+ ae_of_all _ (levelStoppingCurrentGreen_nonneg κ B γ G F hw u _ z)
133
+ rw [← ofReal_integral_eq_lintegral_ofReal hR.integrableOn hRn,
134
+ ← ofReal_integral_eq_lintegral_ofReal hC.integrableOn hCn]
135
+ congr 1
136
+ have : IsFiniteMeasure (P.trim hσ.measurableSpace_le) := isFiniteMeasure_trim hσ.measurableSpace_le
137
+ exact (setIntegral_condExp hσ.measurableSpace_le hR hA).symm.trans
138
+ (integral_congr_ae (ae_restrict_of_ae he))
139
+
140
+ private lemma stopped_setLIntegral_cutoffs
141
+ {Ω : Type*} [MeasurableSpace Ω] (P : Measure Ω)
142
+ (S : Ω → ℝ≥0∞) (hS : Measurable S) (E : Set Ω) (f : Ω → ℝ≥0∞)
143
+ (hz : ∀ ω, S ω = ∞ → f ω = 0) :
144
+ (∫⁻ ω in E, f ω ∂P) =
145
+ ⨆ n : ℕ, ∫⁻ ω in E ∩ {ω | S ω ≤ (n:ℝ≥0)}, f ω ∂P := by
146
+ let A (n : ℕ) := E ∩ {ω | S ω ≤ (n:ℝ≥0)}
147
+ have hmono : Monotone A := by
148
+ intro n k hnk ω hω
149
+ refine ⟨hω.1,?_⟩
150
+ change S ω ≤ ((k:ℝ≥0):ℝ≥0∞)
151
+ exact hω.2.trans (ENNReal.coe_le_coe.mpr (by exact_mod_cast hnk))
152
+ have hcover : (⋃ n, A n) = E ∩ {ω | S ω < ∞} := by
153
+ ext ω
154
+ simp only [mem_iUnion,A,mem_inter_iff,mem_ofPred_eq]
155
+ constructor
156
+ · rintro ⟨n,hnE,hn⟩
157
+ exact ⟨hnE,hn.trans_lt ENNReal.coe_lt_top⟩
158
+ · rintro ⟨hE,hfin⟩
159
+ obtain ⟨n,hn⟩ := exists_nat_ge ((S ω).toReal)
160
+ refine ⟨n,hE,?_⟩
161
+ exact (ENNReal.toReal_le_toReal hfin.ne ENNReal.coe_ne_top).mp (by simpa using hn)
162
+ have hsupp : f.support ⊆ {ω | S ω < ∞} := by
163
+ intro ω hω
164
+ by_contra hn
165
+ exact hω (hz ω (top_le_iff.mp (le_of_not_gt hn)))
166
+ calc
167
+ (∫⁻ ω in E, f ω ∂P) = ∫⁻ ω in {ω | S ω < ∞}, f ω ∂P.restrict E :=
168
+ (setLIntegral_eq_of_support_subset hsupp).symm
169
+ _ = ∫⁻ ω in E ∩ {ω | S ω < ∞}, f ω ∂P := by
170
+ rw [Measure.restrict_restrict (measurableSet_lt hS measurable_const),inter_comm]
171
+ _ = ∫⁻ ω in ⋃ n, A n, f ω ∂P := by rw [hcover]
172
+ _ = _ := setLIntegral_iUnion_of_directed f hmono.directed_le
173
+
174
+ theorem levelStoppingRemainderGreen_setLIntegral
175
+ {Ω : Type*} [mΩ : MeasurableSpace Ω] {P : Measure Ω}
176
+ {B : ℝ≥0 → Ω → ℝ} (hB : IsBrownianReal B P)
177
+ (hBm : Measurable (Function.uncurry B))
178
+ (hc : ∀ ω, Continuous (fun t => B t ω)) (hB0 : ∀ ω, B 0 ω = 0)
179
+ {κ : ℝ} (hκ : 0 < κ) (hκ8 : κ < 8)
180
+ (γ : Ω → ℝ≥0 → ℂ) (G F : Ω → ℝ≥0 → ℂ → ℂ)
181
+ (hw : ∀ ω, IsCapacityTwoWitness (fun s => Real.sqrt κ * B s ω) (γ ω) (G ω) (F ω))
182
+ (z : ℂ) (hz : z ∈ upperHalfPlane) (u : ℝ) (hu : 0 ≤ u)
183
+ (S : Ω → WithTop ℝ≥0)
184
+ (hS : IsStoppingTime (Filtration.natural B (fun s =>
185
+ (hBm.comp (measurable_const.prodMk measurable_id) : Measurable (B s)).stronglyMeasurable)) S)
186
+ (E : Set Ω) (hE : MeasurableSet[hS.measurableSpace] E) :
187
+ (∫⁻ ω in E, ENNReal.ofReal (levelStoppingRemainderGreen κ B γ G u S z ω) ∂P) =
188
+ ∫⁻ ω in E, ENNReal.ofReal (levelStoppingCurrentGreen κ B γ G u S z ω) ∂P := by
189
+ classical
190
+ let ℱ := Filtration.natural B (fun s =>
191
+ (hBm.comp (measurable_const.prodMk measurable_id) : Measurable (B s)).stronglyMeasurable)
192
+ have hRzero (ω : Ω) (hω : S ω = ∞) :
193
+ ENNReal.ofReal (levelStoppingRemainderGreen κ B γ G u S z ω) = 0 := by
194
+ simp [levelStoppingRemainderGreen,hω]
195
+ have hCzero (ω : Ω) (hω : S ω = ∞) :
196
+ ENNReal.ofReal (levelStoppingCurrentGreen κ B γ G u S z ω) = 0 := by
197
+ simp [levelStoppingCurrentGreen,hω]
198
+ rw [stopped_setLIntegral_cutoffs P S hS.measurable' E _ hRzero,
199
+ stopped_setLIntegral_cutoffs P S hS.measurable' E _ hCzero]
200
+ apply iSup_congr
201
+ intro n
202
+ let σ := cutoffStop S (n:ℝ≥0)
203
+ have hσ := cutoffStop_stopping ℱ S hS (n:ℝ≥0)
204
+ have hlocal := levelStoppingRemainderGreen_finite_setLIntegral hB hBm hc hB0 hκ hκ8
205
+ γ G F hw z hz u hu σ hσ (E ∩ {ω | S ω ≤ (n:ℝ≥0)})
206
+ (cutoffStop_success_measurable ℱ S hS (n:ℝ≥0) E hE)
207
+ have he (ω : Ω) (hω : ω ∈ E ∩ {ω | S ω ≤ (n:ℝ≥0)}) : (σ ω : ℝ≥0∞) = S ω := by
208
+ change (cutoffStop S (n:ℝ≥0) ω : WithTop ℝ≥0) = S ω
209
+ rw [cutoffStop_coe,min_eq_left hω.2]
210
+ calc
211
+ _ = ∫⁻ ω in E ∩ {ω | S ω ≤ (n:ℝ≥0)},
212
+ ENNReal.ofReal (levelStoppingRemainderGreen κ B γ G u (fun ω => σ ω) z ω) ∂P := by
213
+ apply setLIntegral_congr_fun (hS.measurableSpace_le _
214
+ (hE.inter (hS.measurableSet_le' (n:ℝ≥0))))
215
+ intro ω hω
216
+ simp only [levelStoppingRemainderGreen,he ω hω]
217
+ split_ifs <;> rfl
218
+ _ = _ := hlocal
219
+ _ = _ := by
220
+ apply setLIntegral_congr_fun (hS.measurableSpace_le _
221
+ (hE.inter (hS.measurableSet_le' (n:ℝ≥0))))
222
+ intro ω hω
223
+ simp only [levelStoppingCurrentGreen,he ω hω]
224
+ split_ifs <;> rfl
225
+
226
+ end SLEExactGauge.Multipoint
227
+
228
+ end
229
+
230
+ end OAI
lean/OAI/Probability/SLE/Mass/LevelStoppingMeasures.lean ADDED
@@ -0,0 +1,280 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Mass.LevelStoppingGreenLimit
2
+ import OAI.Probability.SLE.Mass.LevelMeanMeasure
3
+
4
+ namespace OAI
5
+
6
+ /-! The unreached part of a finite-level approximation at an arbitrary
7
+ stopping time, as a positive measure. -/
8
+
9
+ noncomputable section
10
+ open Set Filter MeasureTheory ProbabilityTheory Classical
11
+ open scoped NNReal ENNReal Topology
12
+
13
+ namespace SLEExactGauge.Multipoint
14
+
15
+ lemma levelApproximationDensity_random_time_joint_measurable
16
+ {Ω : Type*} [MeasurableSpace Ω] {B : ℝ≥0 → Ω → ℝ}
17
+ (hm : ∀ t, Measurable (B t)) (hc : ∀ ω, Continuous (fun t => B t ω))
18
+ (κ u : ℝ) (hu : 0 ≤ u)
19
+ (γ : Ω → ℝ≥0 → ℂ) (G F : Ω → ℝ≥0 → ℂ → ℂ)
20
+ (hw : ∀ ω, IsCapacityTwoWitness (fun t => Real.sqrt κ * B t ω) (γ ω) (G ω) (F ω))
21
+ (S : Ω → ℝ≥0∞) (hS : Measurable S) :
22
+ Measurable (fun p : Ω × ℂ => levelApproximationDensity κ B γ G u (S p.1) p.1 p.2) :=
23
+ Measurable.ite (measurableSet_le
24
+ (actual_radiusLevel_joint_measurable hm hc κ u hu γ G F hw) (hS.comp measurable_fst))
25
+ (actual_stoppedGreen_joint_measurable hm hc κ u hu γ G F hw).ennreal_ofReal measurable_const
26
+
27
+ lemma halfPlaneLevelMeasure_random_time_measurable
28
+ {Ω : Type*} [MeasurableSpace Ω] {B : ℝ≥0 → Ω → ℝ}
29
+ (hm : ∀ t, Measurable (B t)) (hc : ∀ ω, Continuous (fun t => B t ω))
30
+ (κ u : ℝ) (hu : 0 ≤ u)
31
+ (γ : Ω → ℝ≥0 → ℂ) (G F : Ω → ℝ≥0 → ℂ → ℂ)
32
+ (hw : ∀ ω, IsCapacityTwoWitness (fun t => Real.sqrt κ * B t ω) (γ ω) (G ω) (F ω))
33
+ (S : Ω → ℝ≥0∞) (hS : Measurable S) :
34
+ Measurable (fun ω => halfPlaneLevelMeasure κ B γ G u (S ω) ω) := by
35
+ apply Measure.measurable_of_measurable_coe
36
+ intro A hA
37
+ have hAI := (MeasurableEmbedding.subtype_coe isOpen_upperHalfPlane.measurableSet).measurableSet_image.mpr hA
38
+ simp only [halfPlaneLevelMeasure,levelApproximation,
39
+ comap_subtype_coe_apply isOpen_upperHalfPlane.measurableSet,withDensity_apply _ hAI]
40
+ exact (levelApproximationDensity_random_time_joint_measurable hm hc κ u hu γ G F hw S hS).lintegral_prod_right'
41
+
42
+ def halfPlaneStoppingRemainderMeasure {Ω : Type*} (κ : ℝ) (B : ℝ≥0 → Ω → ℝ)
43
+ (γ : Ω → ℝ≥0 → ℂ) (G : Ω → ℝ≥0 → ℂ → ℂ)
44
+ (u : ℝ) (S : Ω → ℝ≥0∞) (ω : Ω) : Measure upperHalfPlane :=
45
+ (volume.withDensity (fun z => ENNReal.ofReal (levelStoppingRemainderGreen κ B γ G u S z ω))).comap Subtype.val
46
+
47
+ def halfPlaneStoppingCurrentMeasure {Ω : Type*} (κ : ℝ) (B : ℝ≥0 → Ω → ℝ)
48
+ (γ : Ω → ℝ≥0 → ℂ) (G : Ω → ℝ≥0 → ℂ → ℂ)
49
+ (u : ℝ) (S : Ω → ℝ≥0∞) (ω : Ω) : Measure upperHalfPlane :=
50
+ (volume.withDensity (fun z => ENNReal.ofReal (levelStoppingCurrentGreen κ B γ G u S z ω))).comap Subtype.val
51
+
52
+ def halfPlaneStoppingGreenMeasure {Ω : Type*} (κ : ℝ) (B : ℝ≥0 → Ω → ℝ)
53
+ (γ : Ω → ℝ≥0 → ℂ) (G : Ω → ℝ≥0 → ℂ → ℂ)
54
+ (S : Ω → ℝ≥0∞) (ω : Ω) : Measure upperHalfPlane :=
55
+ (volume.withDensity (fun z => ENNReal.ofReal (stoppingGreen κ B γ G S z ω))).comap Subtype.val
56
+
57
+ lemma stoppingGreen_joint_measurable
58
+ {Ω : Type*} [MeasurableSpace Ω] {B : ℝ≥0 → Ω → ℝ}
59
+ (hBm : Measurable (Function.uncurry B)) (hc : ∀ ω, Continuous (fun t => B t ω))
60
+ (κ : ℝ) (γ : Ω → ℝ≥0 → ℂ) (G F : Ω → ℝ≥0 → ℂ → ℂ)
61
+ (hw : ∀ ω, IsCapacityTwoWitness (fun t => Real.sqrt κ * B t ω) (γ ω) (G ω) (F ω))
62
+ (S : Ω → ℝ≥0∞) (hS : Measurable S) :
63
+ Measurable (fun p : Ω × ℂ => stoppingGreen κ B γ G S p.2 p.1) :=
64
+ Measurable.ite (measurableSet_lt (hS.comp measurable_fst) measurable_const)
65
+ (actual_greenDensity_random_time_joint_measurable hBm hc κ γ G F hw
66
+ (fun ω => (S ω).toNNReal) (ENNReal.measurable_toNNReal.comp hS)) measurable_const
67
+
68
+ lemma halfPlaneStoppingGreenMeasure_measurable
69
+ {Ω : Type*} [MeasurableSpace Ω] {B : ℝ≥0 → Ω → ℝ}
70
+ (hBm : Measurable (Function.uncurry B)) (hc : ∀ ω, Continuous (fun t => B t ω))
71
+ (κ : ℝ) (γ : Ω → ℝ≥0 → ℂ) (G F : Ω → ℝ≥0 → ℂ → ℂ)
72
+ (hw : ∀ ω, IsCapacityTwoWitness (fun t => Real.sqrt κ * B t ω) (γ ω) (G ω) (F ω))
73
+ (S : Ω → ℝ≥0∞) (hS : Measurable S) :
74
+ Measurable (halfPlaneStoppingGreenMeasure κ B γ G S) := by
75
+ apply Measure.measurable_of_measurable_coe
76
+ intro A hA
77
+ have hAI := (MeasurableEmbedding.subtype_coe isOpen_upperHalfPlane.measurableSet).measurableSet_image.mpr hA
78
+ simp only [halfPlaneStoppingGreenMeasure,comap_subtype_coe_apply isOpen_upperHalfPlane.measurableSet,
79
+ withDensity_apply _ hAI]
80
+ exact (stoppingGreen_joint_measurable hBm hc κ γ G F hw S hS).ennreal_ofReal.lintegral_prod_right'
81
+
82
+ lemma halfPlaneStoppingRemainderMeasure_measurable
83
+ {Ω : Type*} [MeasurableSpace Ω] {B : ℝ≥0 → Ω → ℝ}
84
+ (hm : ∀ t, Measurable (B t)) (hBc : ∀ ω, Continuous (fun t => B t ω))
85
+ (κ u : ℝ) (hu : 0 ≤ u)
86
+ (γ : Ω → ℝ≥0 → ℂ) (G F : Ω → ℝ≥0 → ℂ → ℂ)
87
+ (hw : ∀ ω, IsCapacityTwoWitness (fun t => Real.sqrt κ * B t ω) (γ ω) (G ω) (F ω))
88
+ (S : Ω → ℝ≥0∞) (hS : Measurable S) : Measurable (halfPlaneStoppingRemainderMeasure κ B γ G u S) := by
89
+ apply Measure.measurable_of_measurable_coe
90
+ intro A hA
91
+ have hAI := (MeasurableEmbedding.subtype_coe isOpen_upperHalfPlane.measurableSet).measurableSet_image.mpr hA
92
+ simp only [halfPlaneStoppingRemainderMeasure,comap_subtype_coe_apply isOpen_upperHalfPlane.measurableSet,
93
+ withDensity_apply _ hAI]
94
+ exact (levelStoppingRemainderGreen_joint_measurable hm hBc κ u hu γ G F hw S hS).ennreal_ofReal.lintegral_prod_right'
95
+
96
+ lemma halfPlaneStoppingCurrentMeasure_measurable
97
+ {Ω : Type*} [MeasurableSpace Ω] {B : ℝ≥0 → Ω → ℝ}
98
+ (hBm : Measurable (Function.uncurry B)) (hBc : ∀ ω, Continuous (fun t => B t ω))
99
+ (κ u : ℝ) (hu : 0 ≤ u)
100
+ (γ : Ω → ℝ≥0 → ℂ) (G F : Ω → ℝ≥0 → ℂ → ℂ)
101
+ (hw : ∀ ω, IsCapacityTwoWitness (fun t => Real.sqrt κ * B t ω) (γ ω) (G ω) (F ω))
102
+ (S : Ω → ℝ≥0∞) (hS : Measurable S) : Measurable (halfPlaneStoppingCurrentMeasure κ B γ G u S) := by
103
+ apply Measure.measurable_of_measurable_coe
104
+ intro A hA
105
+ have hAI := (MeasurableEmbedding.subtype_coe isOpen_upperHalfPlane.measurableSet).measurableSet_image.mpr hA
106
+ simp only [halfPlaneStoppingCurrentMeasure,comap_subtype_coe_apply isOpen_upperHalfPlane.measurableSet,
107
+ withDensity_apply _ hAI]
108
+ exact (levelStoppingCurrentGreen_joint_measurable hBm hBc κ u hu γ G F hw S hS).ennreal_ofReal.lintegral_prod_right'
109
+
110
+ lemma halfPlaneLevelMeasure_stopping_split
111
+ {Ω : Type*} [MeasurableSpace Ω] {B : ℝ≥0 → Ω → ℝ}
112
+ (hm : ∀ t, Measurable (B t)) (hBc : ∀ ω, Continuous (fun t => B t ω))
113
+ (κ u : ℝ) (hu : 0 ≤ u)
114
+ (γ : Ω → ℝ≥0 → ℂ) (G F : Ω → ℝ≥0 → ℂ → ℂ)
115
+ (hw : ∀ ω, IsCapacityTwoWitness (fun t => Real.sqrt κ * B t ω) (γ ω) (G ω) (F ω))
116
+ (S : Ω → ℝ≥0∞) (hS : Measurable S) (ω : Ω) :
117
+ halfPlaneLevelMeasure κ B γ G u ∞ ω =
118
+ halfPlaneLevelMeasure κ B γ G u (S ω) ω + halfPlaneStoppingRemainderMeasure κ B γ G u S ω := by
119
+ apply Measure.ext
120
+ intro A hA
121
+ have hAI := (MeasurableEmbedding.subtype_coe isOpen_upperHalfPlane.measurableSet).measurableSet_image.mpr hA
122
+ simp only [Measure.add_apply,halfPlaneLevelMeasure,halfPlaneStoppingRemainderMeasure,levelApproximation,
123
+ comap_subtype_coe_apply isOpen_upperHalfPlane.measurableSet,withDensity_apply _ hAI]
124
+ simp_rw [stopping_level_density_split κ B γ G u S ω]
125
+ have hd : Measurable (fun z => levelApproximationDensity κ B γ G u (S ω) ω z) := by
126
+ have hp : Measurable (fun z : ℂ => (ω,z)) := measurable_const.prodMk measurable_id
127
+ have hh := (levelApproximationDensity_random_time_joint_measurable hm hBc κ u hu
128
+ γ G F hw S hS).comp hp
129
+ simpa only [Function.comp_def] using hh
130
+ exact lintegral_add_left hd _
131
+
132
+ theorem halfPlaneStoppingRemainderMeasure_conditional_mean
133
+ {Ω : Type*} [MeasurableSpace Ω]
134
+ {P : Measure Ω} {B : ℝ≥0 → Ω → ℝ} (hB : IsBrownianReal B P)
135
+ (hBm : Measurable (Function.uncurry B))
136
+ (hBc : ∀ ω, Continuous (fun t => B t ω)) (hB0 : ∀ ω, B 0 ω = 0)
137
+ {κ : ℝ} (hκ : 0 < κ) (hκ8 : κ < 8)
138
+ (γ : Ω → ℝ≥0 → ℂ) (G F : Ω → ℝ≥0 → ℂ → ℂ)
139
+ (hw : ∀ ω, IsCapacityTwoWitness (fun t => Real.sqrt κ * B t ω) (γ ω) (G ω) (F ω))
140
+ (u : ℝ) (hu : 0 ≤ u) (S : Ω → WithTop ℝ≥0)
141
+ (hS : IsStoppingTime (Filtration.natural B (fun s =>
142
+ (hBm.comp (measurable_const.prodMk measurable_id) : Measurable (B s)).stronglyMeasurable)) S)
143
+ (E : Set Ω)
144
+ (hE : MeasurableSet[hS.measurableSpace] E) :
145
+ (P.restrict E).bind (halfPlaneStoppingRemainderMeasure κ B γ G u S) =
146
+ (P.restrict E).bind (halfPlaneStoppingCurrentMeasure κ B γ G u S) := by
147
+ let hm (s : ℝ≥0) : Measurable (B s) := hBm.comp (measurable_const.prodMk measurable_id)
148
+ apply Measure.ext
149
+ intro A hA
150
+ have hAI := (MeasurableEmbedding.subtype_coe isOpen_upperHalfPlane.measurableSet).measurableSet_image.mpr hA
151
+ have hAH : (Subtype.val : upperHalfPlane → ℂ) '' A ⊆ upperHalfPlane := by
152
+ rintro _ ⟨x,_,rfl⟩; exact x.property
153
+ rw [Measure.bind_apply hA (halfPlaneStoppingRemainderMeasure_measurable hm hBc κ u hu γ G F hw S hS.measurable').aemeasurable,
154
+ Measure.bind_apply hA (halfPlaneStoppingCurrentMeasure_measurable hBm hBc κ u hu γ G F hw S hS.measurable').aemeasurable]
155
+ simp only [halfPlaneStoppingRemainderMeasure,halfPlaneStoppingCurrentMeasure,
156
+ comap_subtype_coe_apply isOpen_upperHalfPlane.measurableSet,withDensity_apply _ hAI]
157
+ simpa only [one_mul] using levelStoppingRemainderGreen_spatial_kernel hB hBm hBc hB0 hκ hκ8 γ G F hw
158
+ u hu S hS _ hAI hAH (fun _ => 1) measurable_const E hE
159
+
160
+ theorem halfPlaneLevelMeasure_stopping_conditional_split
161
+ {Ω : Type*} [MeasurableSpace Ω] {P : Measure Ω}
162
+ {B : ℝ≥0 → Ω → ℝ} (hB : IsBrownianReal B P)
163
+ (hBm : Measurable (Function.uncurry B)) (hc : ∀ ω, Continuous (fun t => B t ω))
164
+ (hB0 : ∀ ω, B 0 ω = 0) {κ : ℝ} (hκ : 0 < κ) (hκ8 : κ < 8)
165
+ (γ : Ω → ℝ≥0 → ℂ) (G F : Ω → ℝ≥0 → ℂ → ℂ)
166
+ (hw : ∀ ω, IsCapacityTwoWitness (fun t => Real.sqrt κ * B t ω) (γ ω) (G ω) (F ω))
167
+ (u : ℝ) (hu : 0 ≤ u) (S : Ω → WithTop ℝ≥0)
168
+ (hS : IsStoppingTime (Filtration.natural B (fun s =>
169
+ (hBm.comp (measurable_const.prodMk measurable_id) : Measurable (B s)).stronglyMeasurable)) S)
170
+ (E : Set Ω) (hE : MeasurableSet[hS.measurableSpace] E) :
171
+ (P.restrict E).bind (halfPlaneLevelMeasure κ B γ G u ∞) =
172
+ (P.restrict E).bind (fun ω => halfPlaneLevelMeasure κ B γ G u (S ω) ω) +
173
+ (P.restrict E).bind (halfPlaneStoppingCurrentMeasure κ B γ G u S) := by
174
+ let hm (s : ℝ≥0) : Measurable (B s) := hBm.comp (measurable_const.prodMk measurable_id)
175
+ rw [← halfPlaneStoppingRemainderMeasure_conditional_mean hB hBm hc hB0 hκ hκ8
176
+ γ G F hw u hu S hS E hE]
177
+ apply Measure.ext
178
+ intro A hA
179
+ rw [Measure.add_apply,
180
+ Measure.bind_apply hA (halfPlaneLevelMeasure_measurable hm hc κ u hu γ G F hw ∞).aemeasurable,
181
+ Measure.bind_apply hA (halfPlaneLevelMeasure_random_time_measurable hm hc κ u hu
182
+ γ G F hw S hS.measurable').aemeasurable,
183
+ Measure.bind_apply hA (halfPlaneStoppingRemainderMeasure_measurable hm hc κ u hu
184
+ γ G F hw S hS.measurable').aemeasurable]
185
+ simp_rw [halfPlaneLevelMeasure_stopping_split hm hc κ u hu γ G F hw S hS.measurable',Measure.add_apply]
186
+ exact lintegral_add_left (((Measure.measurable_coe hA).comp
187
+ (halfPlaneLevelMeasure_random_time_measurable hm hc κ u hu γ G F hw S hS.measurable'))) _
188
+
189
+ theorem halfPlaneStoppingGreenMeasure_mean_le
190
+ {Ω : Type*} [MeasurableSpace Ω] {P : Measure Ω}
191
+ {B : ℝ≥0 → Ω → ℝ} (hB : IsBrownianReal B P)
192
+ (hBm : Measurable (Function.uncurry B)) (hc : ∀ ω, Continuous (fun t => B t ω))
193
+ (hB0 : ∀ ω, B 0 ω = 0) {κ : ℝ} (hκ : 0 < κ) (hκ8 : κ < 8)
194
+ (γ : Ω → ℝ≥0 → ℂ) (G F : Ω → ℝ≥0 → ℂ → ℂ)
195
+ (hw : ∀ ω, IsCapacityTwoWitness (fun t => Real.sqrt κ * B t ω) (γ ω) (G ω) (F ω))
196
+ (S : Ω → WithTop ℝ≥0)
197
+ (hS : IsStoppingTime (Filtration.natural B (fun s =>
198
+ (hBm.comp (measurable_const.prodMk measurable_id) : Measurable (B s)).stronglyMeasurable)) S)
199
+ (E : Set Ω) :
200
+ (P.restrict E).bind (halfPlaneStoppingGreenMeasure κ B γ G S) ≤ initialGreenMeasure κ := by
201
+ let : IsProbabilityMeasure P := hB.isGaussianProcess.isProbabilityMeasure
202
+ apply Measure.le_iff.mpr
203
+ intro A hA
204
+ have hAI := (MeasurableEmbedding.subtype_coe isOpen_upperHalfPlane.measurableSet).measurableSet_image.mpr hA
205
+ have hAH : (Subtype.val : upperHalfPlane → ℂ) '' A ⊆ upperHalfPlane := by
206
+ rintro _ ⟨x,_,rfl⟩
207
+ exact x.property
208
+ rw [Measure.bind_apply hA
209
+ (halfPlaneStoppingGreenMeasure_measurable hBm hc κ γ G F hw S hS.measurable').aemeasurable]
210
+ simp only [halfPlaneStoppingGreenMeasure,initialGreenMeasure,
211
+ comap_subtype_coe_apply isOpen_upperHalfPlane.measurableSet,withDensity_apply _ hAI]
212
+ apply (lintegral_mono' Measure.restrict_le_self (le_refl _)).trans
213
+ rw [lintegral_lintegral_swap
214
+ (stoppingGreen_joint_measurable hBm hc κ γ G F hw S hS.measurable').ennreal_ofReal.aemeasurable]
215
+ exact setLIntegral_mono' hAI (fun z hz =>
216
+ stoppingGreen_mean_le hB hBm hc hB0 hκ hκ8 γ G F hw z (hAH hz) S hS)
217
+
218
+ theorem stoppingCurrentGreen_spatial_mean_tendsto
219
+ {Ω : Type*} [MeasurableSpace Ω] (P : Measure Ω)
220
+ {B : ℝ≥0 → Ω → ℝ} (hBm : Measurable (Function.uncurry B))
221
+ (hBc : ∀ ω, Continuous (fun t => B t ω)) (κ : ℝ)
222
+ (γ : Ω → ℝ≥0 → ℂ) (G F : Ω → ℝ≥0 → ℂ → ℂ)
223
+ (hw : ∀ ω, IsCapacityTwoWitness (fun t => Real.sqrt κ * B t ω) (γ ω) (G ω) (F ω))
224
+ (u : ℕ → ℝ) (hu : ∀ n, 0 ≤ u n) (hmono : Monotone u)
225
+ (hlim : Tendsto u atTop atTop) (S : Ω → ℝ≥0∞) (hS : Measurable S) (K : Set ℂ)
226
+ (f : ℂ → ℝ≥0∞) (hf : Measurable f) (E : Set Ω) :
227
+ Tendsto (fun n => ∫⁻ ω in E, (∫⁻ z in K,
228
+ f z * ENNReal.ofReal (levelStoppingCurrentGreen κ B γ G (u n) S z ω) ∂volume) ∂P)
229
+ atTop (𝓝 (∫⁻ ω in E, (∫⁻ z in K, f z * ENNReal.ofReal
230
+ (stoppingGreen κ B γ G S z ω) ∂volume) ∂P)) := by
231
+ let a (n : ℕ) (q : Ω × ℂ) :=
232
+ f q.2 * ENNReal.ofReal (levelStoppingCurrentGreen κ B γ G (u n) S q.2 q.1)
233
+ have ha (n : ℕ) : Measurable (a n) :=
234
+ (hf.comp measurable_snd).mul
235
+ (levelStoppingCurrentGreen_joint_measurable hBm hBc κ (u n) (hu n) γ G F hw S hS).ennreal_ofReal
236
+ have ham (ω : Ω) : Monotone (fun n => fun z => a n (ω,z)) := by
237
+ intro n m hnm z
238
+ exact mul_le_mul' le_rfl (ENNReal.ofReal_le_ofReal
239
+ (levelStoppingCurrentGreen_mono ω (hBc ω) (hw ω) z S (hu n) (hmono hnm)))
240
+ have hal (ω : Ω) : Tendsto (fun n => ∫⁻ z in K, a n (ω,z)) atTop
241
+ (𝓝 (∫⁻ z in K, f z * ENNReal.ofReal
242
+ (stoppingGreen κ B γ G S z ω))) := by
243
+ apply lintegral_tendsto_of_tendsto_of_monotone (μ := volume.restrict K)
244
+ (f := fun n z => a n (ω,z))
245
+ (fun n => ((ha n).comp (measurable_const.prodMk measurable_id)).aemeasurable)
246
+ (Eventually.of_forall (fun z n m hnm => ham ω hnm z))
247
+ filter_upwards [] with z
248
+ apply tendsto_const_nhds.congr'
249
+ exact (levelStoppingCurrentGreen_eventually_eq ω (hBc ω) (hw ω) z S u hu hlim).mono
250
+ (fun n hn => congrArg (fun x : ℝ => f z * ENNReal.ofReal x) hn.symm)
251
+ exact lintegral_tendsto_of_tendsto_of_monotone
252
+ (fun n => (ha n).lintegral_prod_right'.aemeasurable)
253
+ (Eventually.of_forall (fun ω n m hnm => lintegral_mono (ham ω hnm)))
254
+ (Eventually.of_forall hal)
255
+
256
+ theorem halfPlaneStoppingCurrentMeasure_mean_tendsto
257
+ {Ω : Type*} [MeasurableSpace Ω] (P : Measure Ω)
258
+ {B : ℝ≥0 → Ω → ℝ} (hBm : Measurable (Function.uncurry B))
259
+ (hBc : ∀ ω, Continuous (fun t => B t ω)) (κ : ℝ)
260
+ (γ : Ω → ℝ≥0 → ℂ) (G F : Ω → ℝ≥0 → ℂ → ℂ)
261
+ (hw : ∀ ω, IsCapacityTwoWitness (fun t => Real.sqrt κ * B t ω) (γ ω) (G ω) (F ω))
262
+ (u : ℕ → ℝ) (hu : ∀ n, 0 ≤ u n) (hmono : Monotone u)
263
+ (hlim : Tendsto u atTop atTop) (S : Ω → ℝ≥0∞) (hS : Measurable S) (E : Set Ω)
264
+ (A : Set upperHalfPlane) (hA : MeasurableSet A) :
265
+ Tendsto (fun n => (P.restrict E).bind (halfPlaneStoppingCurrentMeasure κ B γ G (u n) S) A)
266
+ atTop (𝓝 ((P.restrict E).bind (halfPlaneStoppingGreenMeasure κ B γ G S) A)) := by
267
+ have hAI := (MeasurableEmbedding.subtype_coe isOpen_upperHalfPlane.measurableSet).measurableSet_image.mpr hA
268
+ simp only [Measure.bind_apply hA
269
+ (halfPlaneStoppingCurrentMeasure_measurable hBm hBc κ (u _) (hu _) γ G F hw S hS).aemeasurable,
270
+ Measure.bind_apply hA (halfPlaneStoppingGreenMeasure_measurable hBm hBc κ γ G F hw S hS).aemeasurable,
271
+ halfPlaneStoppingCurrentMeasure,halfPlaneStoppingGreenMeasure,
272
+ comap_subtype_coe_apply isOpen_upperHalfPlane.measurableSet,withDensity_apply _ hAI]
273
+ simpa only [one_mul] using stoppingCurrentGreen_spatial_mean_tendsto P hBm hBc κ γ G F hw
274
+ u hu hmono hlim S hS _ (fun _ => 1) measurable_const E
275
+
276
+ end SLEExactGauge.Multipoint
277
+
278
+ end
279
+
280
+ end OAI
lean/OAI/Probability/SLE/Mass/LevelStoppingSpatialKernel.lean ADDED
@@ -0,0 +1,114 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Mass.LevelStoppingKernel
2
+
3
+ namespace OAI
4
+
5
+ /-! Joint spatial measurability and the spatial form of the finite-level
6
+ conditional kernel at an arbitrary, possibly infinite, stopping time. -/
7
+
8
+ noncomputable section
9
+ open Set Filter MeasureTheory ProbabilityTheory Classical
10
+ open scoped Topology NNReal ENNReal
11
+
12
+ namespace SLEExactGauge.Multipoint
13
+
14
+ lemma actual_greenDensity_random_time_joint_measurable
15
+ {Ω : Type*} [MeasurableSpace Ω] {B : ℝ≥0 → Ω → ℝ}
16
+ (hBm : Measurable (Function.uncurry B)) (hc : ∀ ω, Continuous (fun t => B t ω))
17
+ (κ : ℝ) (γ : Ω → ℝ≥0 → ℂ) (G F : Ω → ℝ≥0 → ℂ → ℂ)
18
+ (hw : ∀ ω, IsCapacityTwoWitness (fun t => Real.sqrt κ * B t ω) (γ ω) (G ω) (F ω))
19
+ (t : Ω → ℝ≥0) (ht : Measurable t) :
20
+ Measurable (fun p : Ω × ℂ => greenDensity κ
21
+ (fun s => Real.sqrt κ * B s p.1) (γ p.1) (G p.1) (t p.1) p.2) := by
22
+ let U (s : ℝ≥0) (ω : Ω) := Real.sqrt κ * B s ω
23
+ let c := spatialClippedFamily U (hBm.const_mul _) (fun ω => (hc ω).const_mul _)
24
+ have hmap : Measurable (fun p : Ω × ℂ => (t p.1,p.2,p.1)) :=
25
+ (ht.comp measurable_fst).prodMk (measurable_snd.prodMk measurable_fst)
26
+ have hj := (c.jointGreen_measurable κ B hBm).comp hmap
27
+ have he (p : Ω × ℂ) : c.jointGreen κ B (t p.1,p.2,p.1) =
28
+ greenDensity κ (fun s => Real.sqrt κ * B s p.1) (γ p.1) (G p.1) (t p.1) p.2 :=
29
+ c.jointGreen_eq κ B p.1 ((hc p.1).const_mul _) (fun _ => rfl) (hw p.1) _ _
30
+ simpa only [Function.comp_def,he] using hj
31
+
32
+ lemma levelStoppingRemainderGreen_joint_measurable
33
+ {Ω : Type*} [MeasurableSpace Ω] {B : ℝ≥0 → Ω → ℝ}
34
+ (hm : ∀ t, Measurable (B t)) (hc : ∀ ω, Continuous (fun t => B t ω))
35
+ (κ u : ℝ) (hu : 0 ≤ u)
36
+ (γ : Ω → ℝ≥0 → ℂ) (G F : Ω → ℝ≥0 → ℂ → ℂ)
37
+ (hw : ∀ ω, IsCapacityTwoWitness (fun t => Real.sqrt κ * B t ω) (γ ω) (G ω) (F ω))
38
+ (S : Ω → ℝ≥0∞) (hS : Measurable S) :
39
+ Measurable (fun p : Ω × ℂ => levelStoppingRemainderGreen κ B γ G u S p.2 p.1) :=
40
+ Measurable.ite
41
+ (measurableSet_lt (hS.comp measurable_fst)
42
+ (actual_radiusLevel_joint_measurable hm hc κ u hu γ G F hw))
43
+ (actual_stoppedGreen_joint_measurable hm hc κ u hu γ G F hw) measurable_const
44
+
45
+ lemma levelStoppingCurrentGreen_joint_measurable
46
+ {Ω : Type*} [MeasurableSpace Ω] {B : ℝ≥0 → Ω → ℝ}
47
+ (hBm : Measurable (Function.uncurry B)) (hc : ∀ ω, Continuous (fun t => B t ω))
48
+ (κ u : ℝ) (hu : 0 ≤ u)
49
+ (γ : Ω → ℝ≥0 → ℂ) (G F : Ω → ℝ≥0 → ℂ → ℂ)
50
+ (hw : ∀ ω, IsCapacityTwoWitness (fun t => Real.sqrt κ * B t ω) (γ ω) (G ω) (F ω))
51
+ (S : Ω → ℝ≥0∞) (hS : Measurable S) :
52
+ Measurable (fun p : Ω × ℂ => levelStoppingCurrentGreen κ B γ G u S p.2 p.1) := by
53
+ let hm (t : ℝ≥0) : Measurable (B t) := hBm.comp (measurable_const.prodMk measurable_id)
54
+ exact Measurable.ite
55
+ (measurableSet_lt (hS.comp measurable_fst)
56
+ (actual_radiusLevel_joint_measurable hm hc κ u hu γ G F hw))
57
+ (actual_greenDensity_random_time_joint_measurable hBm hc κ γ G F hw
58
+ (fun ω => (S ω).toNNReal) (ENNReal.measurable_toNNReal.comp hS)) measurable_const
59
+
60
+ theorem levelStoppingRemainderGreen_spatial_kernel
61
+ {Ω : Type*} [mΩ : MeasurableSpace Ω] {P : Measure Ω}
62
+ {B : ℝ≥0 → Ω → ℝ} (hB : IsBrownianReal B P)
63
+ (hBm : Measurable (Function.uncurry B))
64
+ (hc : ∀ ω, Continuous (fun t => B t ω)) (hB0 : ∀ ω, B 0 ω = 0)
65
+ {κ : ℝ} (hκ : 0 < κ) (hκ8 : κ < 8)
66
+ (γ : Ω → ℝ≥0 → ℂ) (G F : Ω → ℝ≥0 → ℂ → ℂ)
67
+ (hw : ∀ ω, IsCapacityTwoWitness (fun s => Real.sqrt κ * B s ω) (γ ω) (G ω) (F ω))
68
+ (u : ℝ) (hu : 0 ≤ u) (S : Ω → WithTop ℝ≥0)
69
+ (hS : IsStoppingTime (Filtration.natural B (fun s =>
70
+ (hBm.comp (measurable_const.prodMk measurable_id) : Measurable (B s)).stronglyMeasurable)) S)
71
+ (K : Set ℂ) (hK : MeasurableSet K) (hKH : K ⊆ upperHalfPlane)
72
+ (f : ℂ → ℝ≥0∞) (hf : Measurable f) (E : Set Ω)
73
+ (hE : MeasurableSet[hS.measurableSpace] E) :
74
+ (∫⁻ ω in E, (∫⁻ z in K, f z * ENNReal.ofReal
75
+ (levelStoppingRemainderGreen κ B γ G u S z ω) ∂volume) ∂P) =
76
+ ∫⁻ ω in E, (∫⁻ z in K, f z * ENNReal.ofReal
77
+ (levelStoppingCurrentGreen κ B γ G u S z ω) ∂volume) ∂P := by
78
+ let : IsProbabilityMeasure P := hB.isGaussianProcess.isProbabilityMeasure
79
+ let hm (t : ℝ≥0) : Measurable (B t) := hBm.comp (measurable_const.prodMk measurable_id)
80
+ have hmR := levelStoppingRemainderGreen_joint_measurable hm hc κ u hu γ G F hw S hS.measurable'
81
+ have hmC := levelStoppingCurrentGreen_joint_measurable hBm hc κ u hu γ G F hw S hS.measurable'
82
+ have hR := (hf.comp measurable_snd).mul hmR.ennreal_ofReal
83
+ have hC := (hf.comp measurable_snd).mul hmC.ennreal_ofReal
84
+ conv_lhs => rw [lintegral_lintegral_swap hR.aemeasurable]
85
+ conv_rhs => rw [lintegral_lintegral_swap hC.aemeasurable]
86
+ apply setLIntegral_congr_fun hK
87
+ intro z hz
88
+ dsimp only
89
+ have hp : Measurable (fun ω : Ω => (ω,z)) := measurable_id.prodMk measurable_const
90
+ have hRz := hmR.ennreal_ofReal.comp hp
91
+ have hCz := hmC.ennreal_ofReal.comp hp
92
+ simp only [Function.comp_def] at hRz hCz
93
+ rw [lintegral_const_mul _ hRz,lintegral_const_mul _ hCz]
94
+ rw [levelStoppingRemainderGreen_setLIntegral hB hBm hc hB0 hκ hκ8
95
+ γ G F hw z (hKH hz) u hu S hS E hE]
96
+
97
+ lemma stopping_level_density_split
98
+ {Ω : Type*} (κ : ℝ) (B : ℝ≥0 → Ω → ℝ)
99
+ (γ : Ω → ℝ≥0 → ℂ) (G : Ω → ℝ≥0 → ℂ → ℂ)
100
+ (u : ℝ) (S : Ω → ℝ≥0∞) (ω : Ω) (z : ℂ) :
101
+ levelApproximationDensity κ B γ G u ∞ ω z =
102
+ levelApproximationDensity κ B γ G u (S ω) ω z +
103
+ ENNReal.ofReal (levelStoppingRemainderGreen κ B γ G u S z ω) := by
104
+ by_cases h : radiusLevelTime (γ ω) (G ω) z u ≤ S ω
105
+ · simp only [levelApproximationDensity,le_top,ite_true,ite_eq_left h,
106
+ levelStoppingRemainderGreen,ite_eq_right (not_lt.mpr h),ENNReal.ofReal_zero,add_zero]
107
+ · simp only [levelApproximationDensity,le_top,ite_true,ite_eq_right h,
108
+ levelStoppingRemainderGreen,ite_eq_left (lt_of_not_ge h),zero_add]
109
+
110
+ end SLEExactGauge.Multipoint
111
+
112
+ end
113
+
114
+ end OAI
lean/OAI/Probability/SLE/Mass/LevelStoppingTests.lean ADDED
@@ -0,0 +1,146 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Mass.LevelStoppingMeasures
2
+ import OAI.Probability.SLE.Mass.LevelCurrentTests
3
+ import OAI.Probability.SLE.Mass.LevelConditionalMean
4
+
5
+ namespace OAI
6
+
7
+ /-! Signed compact-test convergence for the Green remainder at arbitrary
8
+ stopping times, and its preservation by the chosen convex tails. -/
9
+
10
+ noncomputable section
11
+ open Set Filter MeasureTheory ProbabilityTheory Classical
12
+ open scoped NNReal ENNReal Topology CompactlySupported
13
+
14
+ namespace SLEExactGauge.Multipoint
15
+
16
+ local instance : LocallyCompactSpace upperHalfPlane := isOpen_upperHalfPlane.locallyCompactSpace
17
+
18
+ lemma levelStoppingCurrentGreen_le_green
19
+ {Ω : Type*} {B : ℝ≥0 → Ω → ℝ} {κ : ℝ}
20
+ {γ : Ω → ℝ≥0 → ℂ} {G F : Ω → ℝ≥0 → ℂ → ℂ}
21
+ (ω : Ω) (hw : IsCapacityTwoWitness
22
+ (fun s => Real.sqrt κ * B s ω) (γ ω) (G ω) (F ω))
23
+ (u : ℝ) (S : Ω → ℝ≥0∞) (z : ℂ) :
24
+ levelStoppingCurrentGreen κ B γ G u S z ω ≤ stoppingGreen κ B γ G S z ω := by
25
+ by_cases hfin : S ω < ∞
26
+ · unfold levelStoppingCurrentGreen stoppingGreen
27
+ rw [ite_eq_left hfin]
28
+ split_ifs
29
+ · exact le_rfl
30
+ · exact greenDensity_nonneg hw κ _ z
31
+ · have hnot : ¬ S ω < radiusLevelTime (γ ω) (G ω) z u :=
32
+ fun h => hfin (h.trans_le le_top)
33
+ simp only [levelStoppingCurrentGreen,stoppingGreen,ite_eq_right hfin,ite_eq_right hnot]
34
+ exact le_rfl
35
+
36
+ lemma halfPlaneStoppingCurrentMeasure_le_green
37
+ {Ω : Type*} {B : ℝ≥0 → Ω → ℝ} {κ : ℝ}
38
+ {γ : Ω → ℝ≥0 → ℂ} {G F : Ω → ℝ≥0 → ℂ → ℂ}
39
+ (ω : Ω) (hw : IsCapacityTwoWitness
40
+ (fun s => Real.sqrt κ * B s ω) (γ ω) (G ω) (F ω))
41
+ (u : ℝ) (S : Ω → ℝ≥0∞) :
42
+ halfPlaneStoppingCurrentMeasure κ B γ G u S ω ≤ halfPlaneStoppingGreenMeasure κ B γ G S ω := by
43
+ apply Measure.le_iff.mpr
44
+ intro A hA
45
+ have hAI := (MeasurableEmbedding.subtype_coe isOpen_upperHalfPlane.measurableSet).measurableSet_image.mpr hA
46
+ simp only [halfPlaneStoppingCurrentMeasure,halfPlaneStoppingGreenMeasure,
47
+ comap_subtype_coe_apply isOpen_upperHalfPlane.measurableSet,withDensity_apply _ hAI]
48
+ exact lintegral_mono (fun z => ENNReal.ofReal_le_ofReal (levelStoppingCurrentGreen_le_green ω hw u S z))
49
+
50
+ lemma halfPlaneStoppingCurrentMeasure_mean_lintegral_test
51
+ {Ω : Type*} [MeasurableSpace Ω] (P : Measure Ω)
52
+ {B : ℝ≥0 → Ω → ℝ} (hBm : Measurable (Function.uncurry B))
53
+ (hBc : ∀ ω, Continuous (fun t => B t ω)) (κ u : ℝ) (hu : 0 ≤ u)
54
+ (γ : Ω → ℝ≥0 → ℂ) (G F : Ω → ℝ≥0 → ℂ → ℂ)
55
+ (hw : ∀ ω, IsCapacityTwoWitness (fun t => Real.sqrt κ * B t ω) (γ ω) (G ω) (F ω))
56
+ (S : Ω → ℝ≥0∞) (hS : Measurable S) (f : upperHalfPlane → ℝ) (hf : Measurable f) :
57
+ (∫⁻ z, ENNReal.ofReal (f z) ∂P.bind (halfPlaneStoppingCurrentMeasure κ B γ G u S)) =
58
+ ∫⁻ ω, (∫⁻ z, ENNReal.ofReal (extendHalfPlaneTest f z) *
59
+ ENNReal.ofReal (levelStoppingCurrentGreen κ B γ G u S z ω) ∂volume) ∂P :=
60
+ lintegral_density_kernel_test P _
61
+ (halfPlaneStoppingCurrentMeasure_measurable hBm hBc κ u hu γ G F hw S hS) _
62
+ (levelStoppingCurrentGreen_joint_measurable hBm hBc κ u hu γ G F hw S hS).ennreal_ofReal
63
+ (fun _ => rfl) f hf
64
+
65
+ lemma halfPlaneStoppingGreenMeasure_mean_lintegral_test
66
+ {Ω : Type*} [MeasurableSpace Ω] (P : Measure Ω)
67
+ {B : ℝ≥0 → Ω → ℝ} (hBm : Measurable (Function.uncurry B))
68
+ (hBc : ∀ ω, Continuous (fun t => B t ω)) (κ : ℝ)
69
+ (γ : Ω → ℝ≥0 → ℂ) (G F : Ω → ℝ≥0 → ℂ → ℂ)
70
+ (hw : ∀ ω, IsCapacityTwoWitness (fun t => Real.sqrt κ * B t ω) (γ ω) (G ω) (F ω))
71
+ (S : Ω → ℝ≥0∞) (hS : Measurable S) (f : upperHalfPlane → ℝ) (hf : Measurable f) :
72
+ (∫⁻ z, ENNReal.ofReal (f z) ∂P.bind (halfPlaneStoppingGreenMeasure κ B γ G S)) =
73
+ ∫⁻ ω, (∫⁻ z, ENNReal.ofReal (extendHalfPlaneTest f z) * ENNReal.ofReal
74
+ (stoppingGreen κ B γ G S z ω) ∂volume) ∂P :=
75
+ lintegral_density_kernel_test P _ (halfPlaneStoppingGreenMeasure_measurable hBm hBc κ γ G F hw S hS) _
76
+ (stoppingGreen_joint_measurable hBm hBc κ γ G F hw S hS).ennreal_ofReal
77
+ (fun _ => rfl) f hf
78
+
79
+ lemma halfPlaneStoppingCurrentMeasure_mean_lintegral_test_tendsto
80
+ {Ω : Type*} [MeasurableSpace Ω] (P : Measure Ω)
81
+ {B : ℝ≥0 → Ω → ℝ} (hBm : Measurable (Function.uncurry B))
82
+ (hBc : ∀ ω, Continuous (fun t => B t ω)) (κ : ℝ)
83
+ (γ : Ω → ℝ≥0 → ℂ) (G F : Ω → ℝ≥0 → ℂ → ℂ)
84
+ (hw : ∀ ω, IsCapacityTwoWitness (fun t => Real.sqrt κ * B t ω) (γ ω) (G ω) (F ω))
85
+ (u : ℕ → ℝ) (hu : ∀ n, 0 ≤ u n) (hmono : Monotone u)
86
+ (hlim : Tendsto u atTop atTop) (S : Ω → ℝ≥0∞) (hS : Measurable S) (E : Set Ω)
87
+ (f : upperHalfPlane → ℝ) (hf : Measurable f) :
88
+ Tendsto (fun n => ∫⁻ z, ENNReal.ofReal (f z)
89
+ ∂(P.restrict E).bind (halfPlaneStoppingCurrentMeasure κ B γ G (u n) S)) atTop
90
+ (𝓝 (∫⁻ z, ENNReal.ofReal (f z) ∂(P.restrict E).bind (halfPlaneStoppingGreenMeasure κ B γ G S))) := by
91
+ simp_rw [halfPlaneStoppingCurrentMeasure_mean_lintegral_test _ hBm hBc κ _ (hu _) γ G F hw S hS f hf,
92
+ halfPlaneStoppingGreenMeasure_mean_lintegral_test _ hBm hBc κ γ G F hw S hS f hf]
93
+ simpa only [Measure.restrict_univ] using stoppingCurrentGreen_spatial_mean_tendsto P hBm hBc κ γ G F hw
94
+ u hu hmono hlim S hS univ (fun z => ENNReal.ofReal (extendHalfPlaneTest f z))
95
+ (extendHalfPlaneTest_measurable f hf).ennreal_ofReal E
96
+
97
+ lemma halfPlaneStoppingCurrentMeasure_mean_le
98
+ {Ω : Type*} [MeasurableSpace Ω] {P : Measure Ω}
99
+ {B : ℝ≥0 → Ω → ℝ} (hB : IsBrownianReal B P)
100
+ (hBm : Measurable (Function.uncurry B)) (hBc : ∀ ω, Continuous (fun t => B t ω))
101
+ (hB0 : ∀ ω, B 0 ω = 0) {κ : ℝ} (hκ : 0 < κ) (hκ8 : κ < 8)
102
+ (γ : Ω → ℝ≥0 → ℂ) (G F : Ω → ℝ≥0 → ℂ → ℂ)
103
+ (hw : ∀ ω, IsCapacityTwoWitness (fun t => Real.sqrt κ * B t ω) (γ ω) (G ω) (F ω))
104
+ (u : ℝ) (hu : 0 ≤ u) (S : Ω → WithTop ℝ≥0)
105
+ (hS : IsStoppingTime (Filtration.natural B (fun s =>
106
+ (hBm.comp (measurable_const.prodMk measurable_id) : Measurable (B s)).stronglyMeasurable)) S)
107
+ (E : Set Ω) :
108
+ (P.restrict E).bind (halfPlaneStoppingCurrentMeasure κ B γ G u S) ≤ initialGreenMeasure κ := by
109
+ apply le_trans ?_ (halfPlaneStoppingGreenMeasure_mean_le hB hBm hBc hB0 hκ hκ8 γ G F hw S hS E)
110
+ apply Measure.le_iff.mpr
111
+ intro A hA
112
+ rw [Measure.bind_apply hA (halfPlaneStoppingCurrentMeasure_measurable hBm hBc κ u hu γ G F hw S hS.measurable').aemeasurable,
113
+ Measure.bind_apply hA (halfPlaneStoppingGreenMeasure_measurable hBm hBc κ γ G F hw S hS.measurable').aemeasurable]
114
+ exact lintegral_mono (fun ω => halfPlaneStoppingCurrentMeasure_le_green ω (hw ω) u S A)
115
+
116
+ theorem halfPlaneStoppingCurrentMeasure_mean_test_tendsto
117
+ {Ω : Type*} [MeasurableSpace Ω] {P : Measure Ω}
118
+ {B : ℝ≥0 → Ω → ℝ} (hB : IsBrownianReal B P)
119
+ (hBm : Measurable (Function.uncurry B)) (hBc : ∀ ω, Continuous (fun t => B t ω))
120
+ (hB0 : ∀ ω, B 0 ω = 0) {κ : ℝ} (hκ : 0 < κ) (hκ8 : κ < 8)
121
+ (γ : Ω → ℝ≥0 → ℂ) (G F : Ω → ℝ≥0 → ℂ → ℂ)
122
+ (hw : ∀ ω, IsCapacityTwoWitness (fun t => Real.sqrt κ * B t ω) (γ ω) (G ω) (F ω))
123
+ (u : ℕ → ℝ) (hu : ∀ n, 0 ≤ u n) (hmono : Monotone u)
124
+ (hlim : Tendsto u atTop atTop) (S : Ω → WithTop ℝ≥0)
125
+ (hS : IsStoppingTime (Filtration.natural B (fun s =>
126
+ (hBm.comp (measurable_const.prodMk measurable_id) : Measurable (B s)).stronglyMeasurable)) S)
127
+ (E : Set Ω)
128
+ (f : C_c(upperHalfPlane,ℝ)) :
129
+ Tendsto (fun n => ∫ z, f z ∂(P.restrict E).bind (halfPlaneStoppingCurrentMeasure κ B γ G (u n) S))
130
+ atTop (𝓝 (∫ z, f z ∂(P.restrict E).bind (halfPlaneStoppingGreenMeasure κ B γ G S))) := by
131
+ let : IsFiniteMeasureOnCompacts (initialGreenMeasure κ) := initialGreenMeasure_finite_on_compacts κ
132
+ have hfi : Integrable f (initialGreenMeasure κ) := f.integrable
133
+ apply integral_tendsto_of_lintegral_pos_neg
134
+ · exact fun n => hfi.mono_measure (halfPlaneStoppingCurrentMeasure_mean_le hB hBm hBc hB0 hκ hκ8
135
+ γ G F hw (u n) (hu n) S hS E)
136
+ · exact hfi.mono_measure (halfPlaneStoppingGreenMeasure_mean_le hB hBm hBc hB0 hκ hκ8 γ G F hw S hS E)
137
+ · exact halfPlaneStoppingCurrentMeasure_mean_lintegral_test_tendsto P hBm hBc κ γ G F hw
138
+ u hu hmono hlim S hS.measurable' E f f.continuous.measurable
139
+ · exact halfPlaneStoppingCurrentMeasure_mean_lintegral_test_tendsto P hBm hBc κ γ G F hw
140
+ u hu hmono hlim S hS.measurable' E (fun z => -f z) f.continuous.measurable.neg
141
+
142
+ end SLEExactGauge.Multipoint
143
+
144
+ end
145
+
146
+ end OAI
lean/OAI/Probability/SLE/Mass/LocalGridMass.lean ADDED
@@ -0,0 +1,118 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Gauge.CoverGrid
2
+
3
+ namespace OAI
4
+
5
+ /-! A translated finite grid count for arbitrary sets of bounded diameter.
6
+ No regularity of the set being covered is required. -/
7
+
8
+ noncomputable section
9
+ open Set Filter MeasureTheory Metric
10
+ open scoped Topology NNReal ENNReal
11
+
12
+ namespace SLEExactGauge
13
+
14
+ lemma localGrid_coordinate {r s x y : ℝ} (hr : 0 < r) (_hs : 0 ≤ s)
15
+ (hxy : |y-x| ≤ s) :
16
+ ⌊x/r⌋-(⌈s/r⌉+2) ≤ ⌊y/r⌋ ∧ ⌊y/r⌋ ≤ ⌊x/r⌋+(⌈s/r⌉+2) := by
17
+ have hx0 := Int.floor_le (x/r)
18
+ have hx1 := Int.lt_floor_add_one (x/r)
19
+ have hy0 := Int.floor_le (y/r)
20
+ have hy1 := Int.lt_floor_add_one (y/r)
21
+ have hc := Int.le_ceil (s/r)
22
+ have hlo : -s/r ≤ (y-x)/r := div_le_div_of_nonneg_right (abs_le.mp hxy).1 hr.le
23
+ have hhi : (y-x)/r ≤ s/r := div_le_div_of_nonneg_right (abs_le.mp hxy).2 hr.le
24
+ rw [sub_div] at hlo hhi
25
+ rw [neg_div] at hlo
26
+ constructor
27
+ · have hh : ((⌊x/r⌋-(⌈s/r⌉+2):ℤ):ℝ) ≤ (⌊y/r⌋:ℝ) := by
28
+ push_cast
29
+ linarith
30
+ exact_mod_cast hh
31
+ · have hh : (⌊y/r⌋:ℝ) ≤ ((⌊x/r⌋+(⌈s/r⌉+2):ℤ):ℝ) := by
32
+ push_cast
33
+ linarith
34
+ exact_mod_cast hh
35
+
36
+ def localGridIndex (r s : ℝ) (z : ℂ) : Finset (ℤ×ℤ) :=
37
+ let N : ℤ := ⌈s/r⌉+2
38
+ (Finset.Icc (⌊z.re/r⌋-N) (⌊z.re/r⌋+N)) ×ˢ
39
+ (Finset.Icc (⌊z.im/r⌋-N) (⌊z.im/r⌋+N))
40
+
41
+ lemma localGrid_covers {r s : ℝ} (hr : 0 < r) (hs : 0 ≤ s) (z : ℂ) :
42
+ closedBall z s ⊆ ⋃ i∈localGridIndex r s z, closedBall (coverGridCenter r i) (2*r) := by
43
+ intro w hw
44
+ have hn : ‖w-z‖ ≤ s := by simpa only [mem_closedBall,dist_eq_norm] using hw
45
+ have hx := localGrid_coordinate hr hs ((Complex.abs_re_le_norm (w-z)).trans hn)
46
+ have hy := localGrid_coordinate hr hs ((Complex.abs_im_le_norm (w-z)).trans hn)
47
+ refine mem_iUnion₂.mpr ⟨(⌊w.re/r⌋,⌊w.im/r⌋),?_,coverGrid_floor_distance hr w⟩
48
+ simpa only [localGridIndex,Finset.mem_product,Finset.mem_Icc,Complex.sub_re,Complex.sub_im]
49
+ using And.intro hx hy
50
+
51
+ lemma localGrid_card_bound {r s : ℝ} (hr : 0 < r) (hs : 0 ≤ s) (z : ℂ) :
52
+ ((localGridIndex r s z).card:ℝ) ≤ 81*max 1 ((s/r)^2) := by
53
+ let N : ℤ := ⌈s/r⌉+2
54
+ have hN : 0 ≤ N := by
55
+ have h := Int.ceil_nonneg (div_nonneg hs hr.le)
56
+ dsimp [N]
57
+ omega
58
+ have hside : 2*(N:ℝ)+1 ≤ 2*(s/r)+7 := by
59
+ have hc := Int.ceil_lt_add_one (s/r)
60
+ dsimp [N]
61
+ push_cast
62
+ linarith
63
+ have hside0 : 0 ≤ 2*(N:ℝ)+1 := by exact_mod_cast (show (0:ℤ) ≤ 2*N+1 by omega)
64
+ have hcard : ((localGridIndex r s z).card:ℝ)=(2*(N:ℝ)+1)^2 := by
65
+ have hx := Int.card_Icc_of_le (a:=⌊z.re/r⌋-N) (b:=⌊z.re/r⌋+N) (by omega)
66
+ have hy := Int.card_Icc_of_le (a:=⌊z.im/r⌋-N) (b:=⌊z.im/r⌋+N) (by omega)
67
+ have hx' : ((Finset.Icc (⌊z.re/r⌋-N) (⌊z.re/r⌋+N)).card:ℝ)=2*(N:ℝ)+1 := by
68
+ have h : ((Finset.Icc (⌊z.re/r⌋-N) (⌊z.re/r⌋+N)).card:ℝ)=
69
+ ((⌊z.re/r⌋:ℝ)+(N:ℝ))+1-((⌊z.re/r⌋:ℝ)-(N:ℝ)) := by exact_mod_cast hx
70
+ linarith
71
+ have hy' : ((Finset.Icc (⌊z.im/r⌋-N) (⌊z.im/r⌋+N)).card:ℝ)=2*(N:ℝ)+1 := by
72
+ have h : ((Finset.Icc (⌊z.im/r⌋-N) (⌊z.im/r⌋+N)).card:ℝ)=
73
+ ((⌊z.im/r⌋:ℝ)+(N:ℝ))+1-((⌊z.im/r⌋:ℝ)-(N:ℝ)) := by exact_mod_cast hy
74
+ linarith
75
+ change (((Finset.Icc _ _) ×ˢ (Finset.Icc _ _)).card:ℝ)=_
76
+ rw [Finset.card_product,Nat.cast_mul,hx',hy',pow_two]
77
+ rw [hcard]
78
+ have hratio : 0 ≤ s/r := div_nonneg hs hr.le
79
+ by_cases hsmall : s/r ≤ 1
80
+ · have h : 2*(N:ℝ)+1 ≤ 9 := by linarith
81
+ have hp := pow_le_pow_left₀ hside0 h 2
82
+ norm_num at hp
83
+ exact hp.trans (by nlinarith [le_max_left (1:ℝ) ((s/r)^2)])
84
+ · have hlarge : 1 ≤ s/r := (lt_of_not_ge hsmall).le
85
+ have h : 2*(N:ℝ)+1 ≤ 9*(s/r) := by linarith
86
+ have hp := pow_le_pow_left₀ hside0 h 2
87
+ calc
88
+ _ ≤ (9*(s/r))^2 := hp
89
+ _ = 81*(s/r)^2 := by ring
90
+ _ ≤ _ := mul_le_mul_of_nonneg_left (le_max_right _ _) (by norm_num)
91
+
92
+ lemma localGrid_mass_bound
93
+ (μ : Measure ℂ) {r s H : ℝ} (hr : 0 < r) (hs : 0 ≤ s) (hH : 0 ≤ H)
94
+ (hcell : ∀ i : ℤ×ℤ, μ (closedBall (coverGridCenter r i) (2*r)) ≤ ENNReal.ofReal H)
95
+ (A : Set ℂ) (hA : ∀ x∈A, ∀ y∈A, dist x y ≤ s) :
96
+ μ A ≤ ENNReal.ofReal (81*H*max 1 ((s/r)^2)) := by
97
+ classical
98
+ rcases A.eq_empty_or_nonempty with rfl | ⟨z,hz⟩
99
+ · simp
100
+ have hcover : A ⊆ closedBall z s := by
101
+ intro w hw
102
+ exact hA w hw z hz
103
+ calc
104
+ μ A ≤ μ (⋃ i∈localGridIndex r s z, closedBall (coverGridCenter r i) (2*r)) :=
105
+ measure_mono (hcover.trans (localGrid_covers hr hs z))
106
+ _ ≤ ∑ i∈localGridIndex r s z, μ (closedBall (coverGridCenter r i) (2*r)) := measure_biUnion_finset_le _ _
107
+ _ ≤ ∑ _i∈localGridIndex r s z, ENNReal.ofReal H := Finset.sum_le_sum (fun i _ => hcell i)
108
+ _ = ENNReal.ofReal (((localGridIndex r s z).card:ℝ)*H) := by
109
+ simp only [Finset.sum_const,nsmul_eq_mul,ENNReal.ofReal_mul (Nat.cast_nonneg _),ENNReal.ofReal_natCast]
110
+ _ ≤ _ := ENNReal.ofReal_le_ofReal (by
111
+ have h := mul_le_mul_of_nonneg_right (localGrid_card_bound hr hs z) hH
112
+ nlinarith)
113
+
114
+ end SLEExactGauge
115
+
116
+ end
117
+
118
+ end OAI
lean/OAI/Probability/SLE/Mass/LocallyFiniteMeasureSubtract.lean ADDED
@@ -0,0 +1,49 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import Mathlib.MeasureTheory.Measure.Sub
2
+ import Mathlib.MeasureTheory.Measure.Typeclasses.SFinite
3
+
4
+ namespace OAI
5
+
6
+ /-! Subtraction for locally finite canonical mass. Cancellation is checked
7
+ on finite restrictions, so no finite total-mass assumption is needed. -/
8
+
9
+ noncomputable section
10
+ open Set MeasureTheory
11
+ open scoped ENNReal
12
+
13
+ namespace SLEExactGauge
14
+
15
+ theorem sigmaFinite_sub_add_cancel_of_le
16
+ {X : Type*} [MeasurableSpace X] {μ ν : Measure X} [SigmaFinite ν]
17
+ (hle : ν ≤ μ) : μ - ν + ν = μ := by
18
+ apply Measure.ext_of_iUnion_eq_univ (iUnion_spanningSets ν)
19
+ intro n
20
+ rw [Measure.restrict_add,Measure.restrict_sub_eq_restrict_sub_restrict
21
+ (measurableSet_spanningSets ν n)]
22
+ have : Fact (ν (spanningSets ν n) < ⊤) := ⟨measure_spanningSets_lt_top ν n⟩
23
+ exact Measure.sub_add_cancel_of_le (Measure.restrict_mono le_rfl hle)
24
+
25
+ theorem sub_apply_of_finite_restriction
26
+ {X : Type*} [MeasurableSpace X] {μ ν : Measure X} (hle : ν ≤ μ)
27
+ {A : Set X} (hA : MeasurableSet A) (hνA : ν A ≠ ⊤) :
28
+ (μ - ν) A = μ A - ν A := by
29
+ have : Fact (ν A < ⊤) := ⟨hνA.lt_top⟩
30
+ calc
31
+ (μ - ν) A = ((μ - ν).restrict A) univ := by simp
32
+ _ = (μ.restrict A - ν.restrict A) univ := by
33
+ rw [Measure.restrict_sub_eq_restrict_sub_restrict hA]
34
+ _ = μ.restrict A univ - ν.restrict A univ :=
35
+ Measure.sub_apply MeasurableSet.univ (Measure.restrict_mono le_rfl hle)
36
+ _ = μ A - ν A := by simp
37
+
38
+ theorem sub_le_sub_right_of_le
39
+ {X : Type*} [MeasurableSpace X] {μ ν ξ : Measure X} [SigmaFinite ξ]
40
+ (hξ : ξ ≤ ν) (hμν : μ ≤ ν) : μ - ξ ≤ ν - ξ := by
41
+ apply Measure.sub_le_of_le_add
42
+ rw [sigmaFinite_sub_add_cancel_of_le hξ]
43
+ exact hμν
44
+
45
+ end SLEExactGauge
46
+
47
+ end
48
+
49
+ end OAI
lean/OAI/Probability/SLE/Mass/MarkedTubeHarmonicMeasure.lean ADDED
@@ -0,0 +1,103 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Geometry.MarkedWindowRoutes
2
+ import OAI.Probability.SLE.Geometry.FiniteExitArcAt
3
+
4
+ namespace OAI
5
+
6
+ /-! Convert the two explicit marked-point Brownian tubes into lower
7
+ bounds for both conformal exit arcs. Every geometric condition concerns
8
+ actual paths in the surviving domain; the only probabilistic input here
9
+ is the generic published conformal Brownian exit law. -/
10
+
11
+ noncomputable section
12
+ open Set Filter MeasureTheory Metric
13
+ open scoped Topology NNReal ENNReal
14
+
15
+ namespace SLEExactGauge.Serpentine
16
+ open RibbonCoordinates CrosscutSides Target
17
+
18
+ lemma marked_window_tubes_opposite_sides
19
+ (hopen : PublishedPlanarDiskOpenness) (w : ℂ) {a : ℝ} (ha : 0 < a)
20
+ (f : ℂ → ℂ) (j : ℂ → ℝ)
21
+ (hf : ContinuousOn f (ball (0 : ℂ) (a / 12)))
22
+ (hfi : InjOn f (ball (0 : ℂ) (a / 12)))
23
+ (hzero : ∀ z ∈ ball (0 : ℂ) (a / 12), (f z).re = 0 ↔ z.im = 0)
24
+ (hrel : ∀ z ∈ ball (0 : ℂ) (a / 12), j (markedCornerChart w z) = (f z).re) :
25
+ ∃ right : Bool,
26
+ (∀ y : ℂ, dist y (markedWindowRoute right w a (1 / 64)) < a / 10000 → 0 < j y) ∧
27
+ (∀ y : ℂ, dist y (markedWindowRoute (!right) w a (1 / 64)) < a / 10000 → j y < 0) := by
28
+ rcases marked_physical_tubes_opposite_sides hopen w ha f j hf hfi hzero hrel with h | h
29
+ · refine ⟨false, ?_⟩
30
+ simpa only [markedWindowRoute_small, Bool.false_eq_true, ↓reduceIte, Bool.not_false] using h
31
+ · refine ⟨true, ?_⟩
32
+ simpa only [markedWindowRoute_small, ↓reduceIte, Bool.not_true, Bool.false_eq_true] using And.symm h
33
+
34
+ theorem marked_tubes_harmonic_bounds
35
+ (hopen : PublishedPlanarDiskOpenness) (hexitLaw : PublishedHalfPlaneConformalExitLaw)
36
+ (W : WienerLaw) (hW : IsWiener W)
37
+ (D : Set ℂ) (hD : IsOpen D) (hDH : D ⊆ upperHalfPlane)
38
+ (g F : ℂ → ℂ) (hg : DifferentiableOn ℂ g D)
39
+ (hF : DifferentiableOn ℂ F upperHalfPlane)
40
+ (hgH : MapsTo g D upperHalfPlane) (hFD : MapsTo F upperHalfPlane D)
41
+ (hFg : ∀ z ∈ D, F (g z) = z) (hgF : ∀ z ∈ upperHalfPlane, g (F z) = z)
42
+ (w : ℂ) (hwD : w ∈ D) {a : ℝ} (ha : 0 < a)
43
+ (h : ℂ ≃ₜ ℂ) (hreal : ∀ x : ℝ, h (x : ℂ) = (x : ℂ))
44
+ (hloc : ContinuousOn (fun z => h (g (markedCornerChart w z))) (ball (0 : ℂ) (a / 12)))
45
+ (hloci : InjOn (fun z => h (g (markedCornerChart w z))) (ball (0 : ℂ) (a / 12)))
46
+ (hlocz : ∀ z ∈ ball (0 : ℂ) (a / 12),
47
+ (h (g (markedCornerChart w z))).re = 0 ↔ z.im = 0)
48
+ (q : ℝ≥0∞)
49
+ (hprob : ∀ right : Bool, q ≤ (W.prod W) {b | ∀ t ∈ Icc (0 : ℝ) 3,
50
+ dist (physicalUnitBrownianPath w b t) (markedWindowRoute right w a t) < a / 10000})
51
+ (hgeom : ∀ (right : Bool) (b : Driver × Driver),
52
+ (∀ t ∈ Icc (0 : ℝ) 3,
53
+ dist (physicalUnitBrownianPath w b t) (markedWindowRoute right w a t) < a / 10000) →
54
+ ∃ τ : ℝ, UnitWindowFirstExit D (physicalUnitBrownianPath w b) τ ∧ (1 / 64 : ℝ) < τ ∧
55
+ ∀ t ∈ Ico (1 / 64 : ℝ) τ, (h (g (physicalUnitBrownianPath w b t))).re ≠ 0) :
56
+ q ≤ ENNReal.ofReal ((g w).arg / Real.pi) ∧
57
+ q ≤ ENNReal.ofReal (1 - (g w).arg / Real.pi) := by
58
+ let E := fun right : Bool => {b | ∀ t ∈ Icc (0 : ℝ) 3,
59
+ dist (physicalUnitBrownianPath w b t) (markedWindowRoute right w a t) < a / 10000}
60
+ obtain ⟨hae, hnegBound, hposBound⟩ := hexitLaw W hW D g F hD hDH
61
+ hg hF hgH hFD hFg hgF w hwD
62
+ obtain ⟨right, hpos, hneg⟩ := marked_window_tubes_opposite_sides hopen w ha
63
+ (fun z => h (g (markedCornerChart w z))) (fun z => (h (g z)).re)
64
+ hloc hloci hlocz (fun _ _ => rfl)
65
+ have hposProb : q ≤ (W.prod W) (unitWindowExitArc D g w 1) := by
66
+ refine (hprob right).trans (finite_exit_event_measure_le_arc_at (W.prod W) D g w h hreal
67
+ hg.continuousOn (E right) (Or.inr rfl) (by norm_num : (0 : ℝ) ≤ 1 / 64) hae
68
+ (hgeom right) ?_)
69
+ intro b hb
70
+ simpa only [one_mul] using hpos _ (hb _ (by norm_num))
71
+ have hnegProb : q ≤ (W.prod W) (unitWindowExitArc D g w (-1)) := by
72
+ refine (hprob (!right)).trans (finite_exit_event_measure_le_arc_at (W.prod W) D g w h hreal
73
+ hg.continuousOn (E (!right)) (Or.inl rfl) (by norm_num : (0 : ℝ) ≤ 1 / 64) hae
74
+ (hgeom (!right)) ?_)
75
+ intro b hb
76
+ have hh := hneg _ (hb _ (by norm_num))
77
+ nlinarith
78
+ exact ⟨hnegProb.trans hnegBound, hposProb.trans hposBound⟩
79
+
80
+ /-- Early survival, a final exit and avoidance of the actual complete
81
+ guide imply the geometric hypotheses in the harmonic-measure theorem. -/
82
+ theorem marked_tube_first_exit_geometry
83
+ (D : Set ℂ) (hD : IsOpen D) (g : ℂ → ℂ) (h : ℂ ≃ₜ ℂ)
84
+ (α : ℝ≥0 → ℂ)
85
+ (hzero : ∀ z ∈ D, (h (g z)).re = 0 → ∃ u : ℝ≥0, 0 < u ∧ α u = z)
86
+ (ζ : ℝ → ℂ) (hc : Continuous ζ)
87
+ (hearly : MapsTo ζ (Icc (0 : ℝ) (1 / 64)) D)
88
+ (hlast : ζ 3 ∉ D)
89
+ (havoid : ∀ t ∈ Icc (1 / 64 : ℝ) 3, ∀ u : ℝ≥0, 0 < u → ζ t ≠ α u) :
90
+ ∃ τ : ℝ, UnitWindowFirstExit D ζ τ ∧ (1 / 64 : ℝ) < τ ∧
91
+ ∀ t ∈ Ico (1 / 64 : ℝ) τ, (h (g (ζ t))).re ≠ 0 := by
92
+ obtain ⟨τ, hτ, hout, hin⟩ := exists_first_domain_exit (L := 3) D hD ζ hc.continuousOn hearly
93
+ ⟨3, by norm_num, hlast⟩
94
+ refine ⟨τ, ⟨⟨by linarith [hτ.1], hτ.2⟩, hout, hin⟩, hτ.1, ?_⟩
95
+ intro t ht he
96
+ obtain ⟨u, hu, hue⟩ := hzero (ζ t) (hin ⟨by linarith [ht.1], ht.2⟩) he
97
+ exact havoid t ⟨ht.1, ht.2.le.trans hτ.2⟩ u hu hue.symm
98
+
99
+ end SLEExactGauge.Serpentine
100
+
101
+ end
102
+
103
+ end OAI
lean/OAI/Probability/SLE/Mass/MassCompensatorEndpoint.lean ADDED
@@ -0,0 +1,117 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Mass.MassCompensatorMesh
2
+
3
+ namespace OAI
4
+
5
+ /-! The last full dyadic cell before a finite or infinite time. -/
6
+
7
+ noncomputable section
8
+ open Set Filter MeasureTheory
9
+ open scoped Topology NNReal ENNReal
10
+
11
+ namespace SLEExactGauge
12
+
13
+ lemma compensatorMeshTime_eq_div (n i : ℕ) :
14
+ compensatorMeshTime n i = (i:ℝ≥0)/(2:ℝ≥0)^n := by
15
+ simp only [compensatorMeshTime,zpow_neg,zpow_natCast,div_eq_mul_inv]
16
+
17
+ @[simp] lemma compensatorMeshTime_end (n : ℕ) :
18
+ compensatorMeshTime n (n*2^n) = n := by
19
+ rw [compensatorMeshTime_eq_div]
20
+ push_cast
21
+ exact mul_div_cancel_right₀ _ (by positivity)
22
+
23
+ def compensatorFiniteIndex (n : ℕ) (t : ℝ≥0) : ℕ :=
24
+ min (n*2^n) ⌊t*(2:ℝ≥0)^n⌋₊
25
+
26
+ lemma compensatorFiniteIndex_le (n : ℕ) (t : ℝ≥0) :
27
+ compensatorFiniteIndex n t ≤ n*2^n := min_le_left _ _
28
+
29
+ lemma compensator_cell_before_iff (n i : ℕ) (t : ℝ≥0) :
30
+ compensatorMeshTime n (i+1) ≤ t ↔ i < ⌊t*(2:ℝ≥0)^n⌋₊ := by
31
+ rw [compensatorMeshTime_eq_div,div_le_iff₀ (by positivity),
32
+ ← Nat.le_floor_iff (show 0 ≤ t*(2:ℝ≥0)^n from zero_le)]
33
+ exact Nat.succ_le_iff
34
+
35
+ lemma compensator_before_sum (n : ℕ) (t : ℝ≥0) (q : ℕ → ℝ) :
36
+ (∑ i ∈ Finset.range (n*2^n),
37
+ if compensatorMeshTime n (i+1) ≤ t then q i else 0) =
38
+ ∑ i ∈ Finset.range (compensatorFiniteIndex n t), q i := by
39
+ simp only [compensator_cell_before_iff]
40
+ rw [← Finset.sum_filter]
41
+ congr 1
42
+ ext i
43
+ simp only [Finset.mem_filter,Finset.mem_range,compensatorFiniteIndex,lt_min_iff]
44
+
45
+ lemma compensatorFiniteIndex_eq_floor {n : ℕ} {t : ℝ≥0} (ht : t ≤ n) :
46
+ compensatorFiniteIndex n t = ⌊t*(2:ℝ≥0)^n⌋₊ := by
47
+ apply min_eq_right
48
+ apply Nat.floor_le_of_le
49
+ push_cast
50
+ exact mul_le_mul_of_nonneg_right ht (by positivity)
51
+
52
+ lemma compensatorEndpoint_le (n : ℕ) (t : ℝ≥0) :
53
+ compensatorMeshTime n (compensatorFiniteIndex n t) ≤ t := by
54
+ rw [compensatorMeshTime_eq_div,div_le_iff₀ (by positivity)]
55
+ exact (Nat.cast_le.mpr (min_le_right _ _)).trans (Nat.floor_le (show 0 ≤ t*(2:ℝ≥0)^n from zero_le))
56
+
57
+ lemma compensatorEndpoint_lower {n : ℕ} {t : ℝ≥0} (ht : t ≤ n) :
58
+ t < compensatorMeshTime n (compensatorFiniteIndex n t)+(2:ℝ≥0)^(-(n:ℤ)) := by
59
+ rw [compensatorFiniteIndex_eq_floor ht,compensatorMeshTime_eq_div,
60
+ zpow_neg,zpow_natCast,← one_div,← add_div,lt_div_iff₀ (by positivity)]
61
+ exact Nat.lt_floor_add_one _
62
+
63
+ /-- A finite endpoint is approached from below even though the grid
64
+ horizon grows. -/
65
+ theorem compensatorEndpoint_tendsto (t : ℝ≥0) :
66
+ Tendsto (fun n => compensatorMeshTime n (compensatorFiniteIndex n t)) atTop (𝓝 t) := by
67
+ apply NNReal.tendsto_coe.mp
68
+ apply tendsto_of_tendsto_of_tendsto_of_le_of_le'
69
+ (show Tendsto (fun n : ℕ => (t:ℝ)-(2:ℝ)^(-(n:ℤ))) atTop (𝓝 (t:ℝ)) from
70
+ by simpa only [sub_zero,zpow_neg,zpow_natCast,inv_pow] using
71
+ tendsto_const_nhds.sub (tendsto_pow_atTop_nhds_zero_of_lt_one
72
+ (show 0 ≤ (2:ℝ)⁻¹ by positivity) (show (2:ℝ)⁻¹<1 by norm_num)))
73
+ tendsto_const_nhds
74
+ · have hn : ∀ᶠ n : ℕ in atTop, t ≤ (n:ℝ≥0) :=
75
+ (tendsto_natCast_atTop_atTop (R := ℝ≥0)).eventually (eventually_ge_atTop t)
76
+ filter_upwards [hn] with n hn
77
+ have h := compensatorEndpoint_lower hn
78
+ have hc : (t:ℝ) < (compensatorMeshTime n (compensatorFiniteIndex n t):ℝ)+
79
+ (2:ℝ)^(-(n:ℤ)) := by exact_mod_cast h
80
+ linarith
81
+ · exact Eventually.of_forall (fun n => by exact_mod_cast compensatorEndpoint_le n t)
82
+
83
+ def compensatorStopIndex (n : ℕ) (T : ℝ≥0∞) : ℕ :=
84
+ if T=∞ then n*2^n else compensatorFiniteIndex n T.toNNReal
85
+
86
+ lemma compensatorStopIndex_measurable {Ω : Type*} [MeasurableSpace Ω]
87
+ (T : Ω → ℝ≥0∞) (hT : Measurable T) (n : ℕ) :
88
+ Measurable (fun ω => compensatorStopIndex n (T ω)) := by
89
+ apply Measurable.ite (measurableSet_eq_fun hT measurable_const) measurable_const
90
+ exact measurable_const.min ((hT.ennreal_toNNReal.mul_const ((2:ℝ≥0)^n)).nat_floor)
91
+
92
+ lemma compensatorStopIndex_le (n : ℕ) (T : ℝ≥0∞) :
93
+ compensatorStopIndex n T ≤ n*2^n := by
94
+ unfold compensatorStopIndex
95
+ split_ifs
96
+ · exact le_rfl
97
+ · exact compensatorFiniteIndex_le _ _
98
+
99
+ def massAtExtendedTime (A : ℝ≥0 → ℝ) (L : ℝ) (T : ℝ≥0∞) : ℝ :=
100
+ if T=∞ then L else A T.toNNReal
101
+
102
+ theorem massAt_compensatorEndpoint_tendsto
103
+ (A : ℝ≥0 → ℝ) (L : ℝ) (hA : Continuous A)
104
+ (hL : Tendsto A atTop (𝓝 L)) (T : ℝ≥0∞) :
105
+ Tendsto (fun n => A (compensatorMeshTime n (compensatorStopIndex n T)))
106
+ atTop (𝓝 (massAtExtendedTime A L T)) := by
107
+ by_cases hT : T=∞
108
+ · simpa only [compensatorStopIndex,massAtExtendedTime,hT,ite_true,
109
+ compensatorMeshTime_end,Function.comp_def] using hL.comp (tendsto_natCast_atTop_atTop (R := ℝ≥0))
110
+ · simpa only [compensatorStopIndex,massAtExtendedTime,hT,ite_false,Function.comp_def] using
111
+ hA.continuousAt.tendsto.comp (compensatorEndpoint_tendsto T.toNNReal)
112
+
113
+ end SLEExactGauge
114
+
115
+ end
116
+
117
+ end OAI
lean/OAI/Probability/SLE/Mass/MassCompensatorMesh.lean ADDED
@@ -0,0 +1,146 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Mass.MassUniquenessMesh
2
+ import OAI.Probability.SLE.MomentGauge
3
+ import Mathlib.Topology.Order.Compact
4
+
5
+ namespace OAI
6
+
7
+ /-! The deterministic quadratic-error estimate for the prescribed dyadic
8
+ potential compensator. A finite terminal limit controls the growing horizon. -/
9
+
10
+ noncomputable section
11
+ open Set Filter MeasureTheory
12
+ open scoped Topology NNReal
13
+
14
+ namespace SLEExactGauge
15
+
16
+ /-- A continuous mass path with a finite terminal limit is uniformly
17
+ continuous even though the compensator mesh horizon grows to infinity. -/
18
+ lemma mass_path_uniformContinuous (A : ℝ≥0 → ℝ) (L : ℝ)
19
+ (hc : Continuous A) (hl : Tendsto A atTop (𝓝 L)) : UniformContinuous A := by
20
+ apply hc.uniformContinuous_of_tendsto_cocompact
21
+ simpa only [cocompact_eq_atTop] using hl
22
+
23
+ def compensatorMeshTime (n i : ℕ) : ℝ≥0 :=
24
+ (i : ℝ≥0) * (2 : ℝ≥0)^(-(n:ℤ))
25
+
26
+ @[simp] lemma compensatorMeshTime_zero (n : ℕ) : compensatorMeshTime n 0=0 := by
27
+ simp [compensatorMeshTime]
28
+
29
+ lemma compensatorMeshTime_mono (n : ℕ) : Monotone (compensatorMeshTime n) := by
30
+ intro i j hij
31
+ exact mul_le_mul_of_nonneg_right (by exact_mod_cast hij) (by positivity)
32
+
33
+ lemma compensatorMeshTime_dist (n i : ℕ) :
34
+ dist (compensatorMeshTime n (i+1)) (compensatorMeshTime n i) = (2:ℝ)^(-(n:ℤ)) := by
35
+ rw [NNReal.dist_eq]
36
+ simp only [compensatorMeshTime,NNReal.coe_mul,NNReal.coe_zpow,NNReal.coe_ofNat,
37
+ NNReal.coe_natCast,NNReal.coe_add,NNReal.coe_one,Nat.cast_add,Nat.cast_one]
38
+ rw [show ((i:ℝ)+1)*(2:ℝ)^(-(n:ℤ))-(i:ℝ)*(2:ℝ)^(-(n:ℤ)) =
39
+ (2:ℝ)^(-(n:ℤ)) by ring, abs_of_pos (by positivity)]
40
+
41
+ lemma compensatorMeshTime_small_increments (A : ℝ≥0 → ℝ) (L : ℝ)
42
+ (hc : Continuous A) (hl : Tendsto A atTop (𝓝 L)) :
43
+ ∀ ε : ℝ, 0 < ε → ∀ᶠ n : ℕ in atTop, ∀ i : ℕ,
44
+ |A (compensatorMeshTime n (i+1))-A (compensatorMeshTime n i)| ≤ ε := by
45
+ intro ε hε
46
+ obtain ⟨δ,hδ,hAδ⟩ := Metric.uniformContinuous_iff.mp
47
+ (mass_path_uniformContinuous A L hc hl) ε hε
48
+ have hmesh : Tendsto (fun n : ℕ => (2:ℝ)^(-(n:ℤ))) atTop (𝓝 0) := by
49
+ simpa only [zpow_neg, zpow_natCast, inv_pow] using
50
+ (tendsto_pow_atTop_nhds_zero_of_lt_one (show 0 ≤ (2:ℝ)⁻¹ by positivity)
51
+ (show (2:ℝ)⁻¹ < 1 by norm_num))
52
+ filter_upwards [hmesh.eventually (gt_mem_nhds hδ)] with n hn i
53
+ have h := hAδ (a := compensatorMeshTime n (i+1)) (b := compensatorMeshTime n i)
54
+ (by simpa only [compensatorMeshTime_dist] using hn)
55
+ exact (by simpa only [Real.dist_eq] using h.le)
56
+
57
+ def compensatorQuadraticError (A : ℝ≥0 → ℝ) (n : ℕ) : ℝ :=
58
+ ∑ i ∈ Finset.range (n*2^n),
59
+ (A (compensatorMeshTime n (i+1))-A (compensatorMeshTime n i))^2
60
+
61
+ lemma compensatorQuadraticError_nonneg (A : ℝ≥0 → ℝ) (n : ℕ) :
62
+ 0 ≤ compensatorQuadraticError A n :=
63
+ Finset.sum_nonneg (fun _ _ => sq_nonneg _)
64
+
65
+ lemma compensatorQuadraticError_le (A : ℝ≥0 → ℝ) (L : ℝ)
66
+ (hm : Monotone A) (h0 : A 0=0) (hb : ∀ t, A t ≤ L)
67
+ (n : ℕ) {ε : ℝ} (hε : 0 ≤ ε)
68
+ (hsmall : ∀ i : ℕ, A (compensatorMeshTime n (i+1))-A (compensatorMeshTime n i) ≤ ε) :
69
+ compensatorQuadraticError A n ≤ ε*L := by
70
+ have hsum : (∑ i ∈ Finset.range (n*2^n),
71
+ (A (compensatorMeshTime n (i+1))-A (compensatorMeshTime n i))) ≤ L := by
72
+ rw [Finset.sum_range_sub (fun i => A (compensatorMeshTime n i)) (n*2^n),
73
+ compensatorMeshTime_zero,h0,sub_zero]
74
+ exact hb _
75
+ calc
76
+ compensatorQuadraticError A n ≤ ∑ i ∈ Finset.range (n*2^n),
77
+ ε*(A (compensatorMeshTime n (i+1))-A (compensatorMeshTime n i)) := by
78
+ apply Finset.sum_le_sum
79
+ intro i _
80
+ have hnonneg := sub_nonneg.mpr (hm (compensatorMeshTime_mono n (Nat.le_succ i)))
81
+ nlinarith [hsmall i]
82
+ _ = ε*∑ i ∈ Finset.range (n*2^n),
83
+ (A (compensatorMeshTime n (i+1))-A (compensatorMeshTime n i)) :=
84
+ (Finset.mul_sum _ _ _).symm
85
+ _ ≤ ε*L := mul_le_mul_of_nonneg_left hsum hε
86
+
87
+ lemma compensatorQuadraticError_le_terminal_sq (A : ℝ≥0 → ℝ) (L : ℝ)
88
+ (hm : Monotone A) (h0 : A 0=0) (hb : ∀ t, A t ≤ L) (n : ℕ) :
89
+ compensatorQuadraticError A n ≤ L^2 := by
90
+ have hL : 0 ≤ L := by simpa only [h0] using hb 0
91
+ simpa only [pow_two] using compensatorQuadraticError_le A L hm h0 hb n hL (fun i => by
92
+ have hAi : 0 ≤ A (compensatorMeshTime n i) := by
93
+ rw [← h0]
94
+ exact hm (show 0 ≤ _ from zero_le)
95
+ linarith [hb (compensatorMeshTime n (i+1))])
96
+
97
+ /-- The accumulated squared mass increments vanish for the exact growing
98
+ horizon and dyadic mesh used by the paper's potential formula. -/
99
+ theorem compensatorQuadraticError_tendsto_zero (A : ℝ≥0 → ℝ) (L : ℝ)
100
+ (hm : Monotone A) (h0 : A 0=0) (hc : Continuous A)
101
+ (hl : Tendsto A atTop (𝓝 L)) (hb : ∀ t, A t ≤ L) :
102
+ Tendsto (compensatorQuadraticError A) atTop (𝓝 0) := by
103
+ have hL : 0 ≤ L := by simpa only [h0] using hb 0
104
+ apply tendsto_order.mpr
105
+ constructor
106
+ · intro a ha
107
+ exact Eventually.of_forall (fun n => ha.trans_le (compensatorQuadraticError_nonneg A n))
108
+ · intro b hb0
109
+ have hd : 0 < b/(L+1) := div_pos hb0 (by linarith)
110
+ filter_upwards [compensatorMeshTime_small_increments A L hc hl _ hd] with n hn
111
+ have hbound := compensatorQuadraticError_le A L hm h0 hb n hd.le
112
+ (fun i => (le_abs_self _).trans (hn i))
113
+ have he : b/(L+1)*(L+1)=b := div_mul_cancel₀ b (by linarith)
114
+ nlinarith
115
+
116
+ /-- Dominated convergence for the exact quadratic mesh error; the bound
117
+ requires only the second terminal moment, not a uniform time horizon. -/
118
+ theorem compensatorQuadraticError_mean_tendsto_zero
119
+ {Ω : Type*} [MeasurableSpace Ω] (P : Measure Ω)
120
+ (A : ℝ≥0 → Ω → ℝ) (L : Ω → ℝ)
121
+ (hA : ∀ t, Measurable (A t)) (hL : Integrable (fun ω => L ω^2) P)
122
+ (hp : ∀ᵐ ω ∂P, Monotone (fun t => A t ω) ∧ A 0 ω=0 ∧
123
+ Continuous (fun t => A t ω) ∧ Tendsto (fun t => A t ω) atTop (𝓝 (L ω)) ∧
124
+ ∀ t, A t ω ≤ L ω) :
125
+ Tendsto (fun n => ∫ ω, compensatorQuadraticError (fun t => A t ω) n ∂P)
126
+ atTop (𝓝 0) := by
127
+ have hm (n : ℕ) : Measurable (fun ω => compensatorQuadraticError (fun t => A t ω) n) := by
128
+ apply Finset.measurable_sum
129
+ intro i _
130
+ exact ((hA _).sub (hA _)).pow_const 2
131
+ have hb (n : ℕ) : ∀ᵐ ω ∂P, ‖compensatorQuadraticError (fun t => A t ω) n‖ ≤ L ω^2 := by
132
+ filter_upwards [hp] with ω hω
133
+ rw [Real.norm_of_nonneg (compensatorQuadraticError_nonneg _ _)]
134
+ exact compensatorQuadraticError_le_terminal_sq _ _ hω.1 hω.2.1 hω.2.2.2.2 n
135
+ have hl : ∀ᵐ ω ∂P, Tendsto (fun n => compensatorQuadraticError (fun t => A t ω) n)
136
+ atTop (𝓝 0) := by
137
+ filter_upwards [hp] with ω hω
138
+ exact compensatorQuadraticError_tendsto_zero _ _ hω.1 hω.2.1 hω.2.2.1 hω.2.2.2.1 hω.2.2.2.2
139
+ simpa only [integral_zero] using tendsto_integral_of_dominated_convergence
140
+ (fun ω => L ω^2) (fun n => (hm n).aestronglyMeasurable) hL hb hl
141
+
142
+ end SLEExactGauge
143
+
144
+ end
145
+
146
+ end OAI
lean/OAI/Probability/SLE/Mass/MassCompensatorRecovery.lean ADDED
@@ -0,0 +1,144 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Mass.MassCompensatorEndpoint
2
+ import OAI.Probability.SLE.Mass.MassCompensatorSelection
3
+
4
+ namespace OAI
5
+
6
+ /-! Recovery of a continuous finite mass path from its discrete
7
+ predictable increments, with the paper's growing dyadic horizon. -/
8
+
9
+ noncomputable section
10
+ open Set Filter MeasureTheory ProbabilityTheory
11
+ open scoped Topology NNReal ENNReal
12
+
13
+ namespace SLEExactGauge
14
+
15
+ variable {Ω : Type*} [mΩ : MeasurableSpace Ω] (P : Measure Ω) [IsProbabilityMeasure P]
16
+
17
+ def meshMassIncrement (A : ℝ≥0 → Ω → ℝ) (n i : ℕ) (ω : Ω) : ℝ :=
18
+ A (compensatorMeshTime n (i+1)) ω-A (compensatorMeshTime n i) ω
19
+
20
+ def meshMassCompensator (ℱ : ℕ → Filtration ℕ mΩ) (A : ℝ≥0 → Ω → ℝ)
21
+ (n j : ℕ) (ω : Ω) : ℝ :=
22
+ ∑ i ∈ Finset.range j, condExp (ℱ n i) P (meshMassIncrement A n i) ω
23
+
24
+ omit [IsProbabilityMeasure P] in
25
+ lemma meshMassIncrement_memLp
26
+ (A : ℝ≥0 → Ω → ℝ) (L : Ω → ℝ) (hL : MemLp L 2 P)
27
+ (hA : ∀ t, Measurable (A t))
28
+ (hp : ∀ᵐ ω ∂P, Monotone (fun t => A t ω) ∧ A 0 ω=0 ∧ ∀ t, A t ω ≤ L ω)
29
+ (n i : ℕ) : MemLp (meshMassIncrement A n i) 2 P := by
30
+ apply hL.mono' (((hA _).sub (hA _)).aestronglyMeasurable)
31
+ filter_upwards [hp] with ω hω
32
+ have hn : 0 ≤ meshMassIncrement A n i ω :=
33
+ sub_nonneg.mpr (hω.1 (compensatorMeshTime_mono n (Nat.le_succ i)))
34
+ have hz : 0 ≤ A (compensatorMeshTime n i) ω := by
35
+ rw [← hω.2.1]
36
+ exact hω.1 (show 0 ≤ _ from zero_le)
37
+ simp only [Pi.sub_apply]
38
+ change 0 ≤ A (compensatorMeshTime n (i+1)) ω-A (compensatorMeshTime n i) ω at hn
39
+ rw [Real.norm_of_nonneg hn]
40
+ linarith [hω.2.2 (compensatorMeshTime n (i+1))]
41
+
42
+ omit [IsProbabilityMeasure P] in
43
+ lemma meshMassCompensator_decomposition
44
+ (ℱ : ℕ → Filtration ℕ mΩ) (A : ℝ≥0 → Ω → ℝ) (n j : ℕ) (ω : Ω) :
45
+ meshMassCompensator P ℱ A n j ω =
46
+ A (compensatorMeshTime n j) ω-A 0 ω-
47
+ centeredMassPartialSum P (ℱ n) (meshMassIncrement A n) j ω := by
48
+ unfold centeredMassPartialSum meshMassCompensator
49
+ rw [Finset.sum_sub_distrib]
50
+ have he : (∑ i ∈ Finset.range j, meshMassIncrement A n i ω) =
51
+ A (compensatorMeshTime n j) ω-A 0 ω := by
52
+ simp only [meshMassIncrement]
53
+ rw [Finset.sum_range_sub (fun i => A (compensatorMeshTime n i) ω) j,compensatorMeshTime_zero]
54
+ rw [he]
55
+ ring
56
+
57
+ theorem meshMassCentered_selected_tendstoInMeasure
58
+ (ℱ : ℕ → Filtration ℕ mΩ) (A : ℝ≥0 → Ω → ℝ) (L : Ω → ℝ)
59
+ (hA : ∀ t, Measurable (A t))
60
+ (hgrid : ∀ n i, StronglyMeasurable[ℱ n i] (A (compensatorMeshTime n i)))
61
+ (hL : MemLp L 2 P)
62
+ (hp : ∀ᵐ ω ∂P, Monotone (fun t => A t ω) ∧ A 0 ω=0 ∧
63
+ Continuous (fun t => A t ω) ∧ Tendsto (fun t => A t ω) atTop (𝓝 (L ω)) ∧
64
+ ∀ t, A t ω ≤ L ω)
65
+ (J : ℕ → Ω → ℕ) (hJ : ∀ n ω, J n ω ≤ n*2^n) :
66
+ TendstoInMeasure P
67
+ (fun n ω => centeredMassPartialSum P (ℱ n) (meshMassIncrement A n) (J n ω) ω)
68
+ atTop 0 := by
69
+ apply centeredMassPartialSum_selected_tendstoInMeasure P ℱ (meshMassIncrement A)
70
+ (fun n i => meshMassIncrement_memLp P A L hL hA
71
+ (hp.mono (fun ω hω => ⟨hω.1,hω.2.1,hω.2.2.2.2⟩)) n i)
72
+ (fun n i => (hgrid n (i+1)).sub ((hgrid n i).mono (ℱ n |>.mono (Nat.le_succ i))))
73
+ (fun n => n*2^n) J hJ
74
+ exact compensatorQuadraticError_mean_tendsto_zero P A L hA hL.integrable_sq hp
75
+
76
+ omit [IsProbabilityMeasure P] in
77
+ lemma meshMassCompensator_selected_measurable
78
+ (ℱ : ℕ → Filtration ℕ mΩ) (A : ℝ≥0 → Ω → ℝ)
79
+ (n : ℕ) (J : Ω → ℕ) (hJ : Measurable J) :
80
+ Measurable (fun ω => meshMassCompensator P ℱ A n (J ω) ω) := by
81
+ have hjoint : Measurable (fun z : ℕ × Ω => meshMassCompensator P ℱ A n z.1 z.2) := by
82
+ apply measurable_from_prod_countable_right
83
+ intro j
84
+ change Measurable (fun ω => ∑ i ∈ Finset.range j, condExp (ℱ n i) P (meshMassIncrement A n i) ω)
85
+ apply Finset.measurable_sum
86
+ intro i _
87
+ exact stronglyMeasurable_condExp.measurable.le (ℱ n |>.le i)
88
+ exact hjoint.comp (hJ.prodMk measurable_id)
89
+
90
+ /-- Any measurable choice of endpoints where the sampled mass has its
91
+ pathwise limit recovers that same mass from the predictable increments. -/
92
+ theorem meshMassCompensator_selected_tendstoInMeasure
93
+ (ℱ : ℕ → Filtration ℕ mΩ) (A : ℝ≥0 → Ω → ℝ) (L V : Ω → ℝ)
94
+ (hA : ∀ t, Measurable (A t))
95
+ (hgrid : ∀ n i, StronglyMeasurable[ℱ n i] (A (compensatorMeshTime n i)))
96
+ (hL : MemLp L 2 P)
97
+ (hp : ∀ᵐ ω ∂P, Monotone (fun t => A t ω) ∧ A 0 ω=0 ∧
98
+ Continuous (fun t => A t ω) ∧ Tendsto (fun t => A t ω) atTop (𝓝 (L ω)) ∧
99
+ ∀ t, A t ω ≤ L ω)
100
+ (J : ℕ → Ω → ℕ) (hJm : ∀ n, Measurable (J n))
101
+ (hJ : ∀ n ω, J n ω ≤ n*2^n)
102
+ (hJV : ∀ᵐ ω ∂P, Tendsto (fun n => A (compensatorMeshTime n (J n ω)) ω)
103
+ atTop (𝓝 (V ω))) :
104
+ TendstoInMeasure P (fun n ω => meshMassCompensator P ℱ A n (J n ω) ω) atTop V := by
105
+ have hZ := meshMassCentered_selected_tendstoInMeasure P ℱ A L hA hgrid hL hp J hJ
106
+ apply (exists_seq_tendstoInMeasure_atTop_iff
107
+ (fun n => (meshMassCompensator_selected_measurable P ℱ A n (J n) (hJm n)).aestronglyMeasurable)).mpr
108
+ intro ns hns
109
+ obtain ⟨ms,hms,hlim⟩ := (hZ.comp hns.tendsto_atTop).exists_seq_tendsto_ae
110
+ refine ⟨ms,hms,?_⟩
111
+ filter_upwards [hp,hJV,hlim] with ω hω hV hZω
112
+ have ht := (hV.comp (hns.tendsto_atTop.comp hms.tendsto_atTop)).sub hZω
113
+ simp only [Pi.zero_apply,sub_zero,Function.comp_def] at ht
114
+ convert ht using 1
115
+ funext n
116
+ rw [meshMassCompensator_decomposition,hω.2.1,sub_zero]
117
+
118
+ /-- The exact last-full-cell convention, including an infinite endpoint,
119
+ recovers the stopped mass in probability. -/
120
+ theorem meshMassCompensator_stopped_tendstoInMeasure
121
+ (ℱ : ℕ → Filtration ℕ mΩ) (A : ℝ≥0 → Ω → ℝ) (L : Ω → ℝ)
122
+ (hA : ∀ t, Measurable (A t))
123
+ (hgrid : ∀ n i, StronglyMeasurable[ℱ n i] (A (compensatorMeshTime n i)))
124
+ (hL : MemLp L 2 P)
125
+ (hp : ∀ᵐ ω ∂P, Monotone (fun t => A t ω) ∧ A 0 ω=0 ∧
126
+ Continuous (fun t => A t ω) ∧ Tendsto (fun t => A t ω) atTop (𝓝 (L ω)) ∧
127
+ ∀ t, A t ω ≤ L ω)
128
+ (T : Ω → ℝ≥0∞) (hT : Measurable T) :
129
+ TendstoInMeasure P
130
+ (fun n ω => meshMassCompensator P ℱ A n (compensatorStopIndex n (T ω)) ω)
131
+ atTop (fun ω => massAtExtendedTime (fun t => A t ω) (L ω) (T ω)) := by
132
+ apply meshMassCompensator_selected_tendstoInMeasure P ℱ A L _ hA hgrid hL hp
133
+ (fun n ω => compensatorStopIndex n (T ω))
134
+ (fun n => compensatorStopIndex_measurable T hT n)
135
+ (fun n ω => compensatorStopIndex_le n (T ω))
136
+ filter_upwards [hp] with ω hω
137
+ exact massAt_compensatorEndpoint_tendsto (fun t => A t ω) (L ω)
138
+ hω.2.2.1 hω.2.2.2.1 (T ω)
139
+
140
+ end SLEExactGauge
141
+
142
+ end
143
+
144
+ end OAI
lean/OAI/Probability/SLE/Mass/MassCompensatorSelection.lean ADDED
@@ -0,0 +1,81 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Mass.MassCompensatorVariance
2
+ import Mathlib.MeasureTheory.Function.ConvergenceInMeasure
3
+
4
+ namespace OAI
5
+
6
+ /-! The compensator error at a selected grid endpoint. The endpoint may
7
+ depend on the whole path; the maximal bound does not require it to be a
8
+ discrete stopping time. -/
9
+
10
+ noncomputable section
11
+ open Set Filter MeasureTheory ProbabilityTheory
12
+ open scoped Topology NNReal ENNReal
13
+
14
+ namespace SLEExactGauge
15
+
16
+ variable {Ω : Type*} [mΩ : MeasurableSpace Ω] (P : Measure Ω) [IsProbabilityMeasure P]
17
+
18
+ lemma centeredMassPartialSum_selected_bound
19
+ (ℱ : Filtration ℕ mΩ) (D : ℕ → Ω → ℝ)
20
+ (hD : ∀ i, MemLp (D i) 2 P)
21
+ (hDm : ∀ i, StronglyMeasurable[ℱ (i+1)] (D i))
22
+ (N : ℕ) (J : Ω → ℕ) (hJ : ∀ ω, J ω ≤ N) (ε : ℝ) (hε : 0 < ε) :
23
+ ENNReal.ofReal (ε^2) * P {ω | ε ≤ |centeredMassPartialSum P ℱ D (J ω) ω|} ≤
24
+ ENNReal.ofReal (∫ ω, ∑ i ∈ Finset.range N, D i ω^2 ∂P) := by
25
+ have hs : {ω | ε ≤ |centeredMassPartialSum P ℱ D (J ω) ω|} ⊆
26
+ {ω | ε^2 ≤ (Finset.range (N+1)).sup' Finset.nonempty_range_add_one
27
+ (fun j => centeredMassPartialSum P ℱ D j ω^2)} := by
28
+ intro ω hω
29
+ change ε^2 ≤ _
30
+ apply Finset.le_sup'_of_le (fun j => centeredMassPartialSum P ℱ D j ω^2)
31
+ (Finset.mem_range.mpr (Nat.lt_succ_of_le (hJ ω)))
32
+ have hh := mul_self_le_mul_self hε.le hω
33
+ simpa only [sq_abs,← pow_two] using hh
34
+ have hb := centeredMassPartialSum_maximal_error P ℱ D hD hDm
35
+ (NNReal.mk (ε^2) (sq_nonneg ε)) N
36
+ have hb' : ENNReal.ofReal (ε^2) * P {ω | ε^2 ≤
37
+ (Finset.range (N+1)).sup' Finset.nonempty_range_add_one
38
+ (fun j => centeredMassPartialSum P ℱ D j ω^2)} ≤
39
+ ENNReal.ofReal (∫ ω, ∑ i ∈ Finset.range N, D i ω^2 ∂P) := by
40
+ simpa only [ENNReal.ofReal_eq_coe_nnreal (sq_nonneg ε),NNReal.coe_mk] using hb
41
+ exact (mul_le_mul_of_nonneg_left (measure_mono hs)
42
+ (show 0 ≤ ENNReal.ofReal (ε^2) from zero_le)).trans hb'
43
+
44
+ /-- Vanishing expected quadratic increments imply that the centered
45
+ compensator vanishes in probability at every bounded selected index. -/
46
+ theorem centeredMassPartialSum_selected_tendstoInMeasure
47
+ (ℱ : ℕ → Filtration ℕ mΩ) (D : ℕ → ℕ → Ω → ℝ)
48
+ (hD : ∀ n i, MemLp (D n i) 2 P)
49
+ (hDm : ∀ n i, StronglyMeasurable[ℱ n (i+1)] (D n i))
50
+ (N : ℕ → ℕ) (J : ℕ → Ω → ℕ) (hJ : ∀ n ω, J n ω ≤ N n)
51
+ (hE : Tendsto (fun n => ∫ ω, ∑ i ∈ Finset.range (N n), D n i ω^2 ∂P)
52
+ atTop (𝓝 0)) :
53
+ TendstoInMeasure P (fun n ω => centeredMassPartialSum P (ℱ n) (D n) (J n ω) ω)
54
+ atTop 0 := by
55
+ rw [tendstoInMeasure_iff_norm]
56
+ intro ε hε
57
+ let c : ℝ≥0∞ := ENNReal.ofReal (ε^2)
58
+ have hc0 : c ≠ 0 := (ENNReal.ofReal_pos.mpr (sq_pos_of_pos hε)).ne'
59
+ have hcT : c ≠ ∞ := ENNReal.ofReal_ne_top
60
+ have hb (n : ℕ) : P {ω | ε ≤ |centeredMassPartialSum P (ℱ n) (D n) (J n ω) ω|} ≤
61
+ c⁻¹*ENNReal.ofReal (∫ ω, ∑ i ∈ Finset.range (N n), D n i ω^2 ∂P) := by
62
+ calc
63
+ _ = c⁻¹*(c*P {ω | ε ≤ |centeredMassPartialSum P (ℱ n) (D n) (J n ω) ω|}) := by
64
+ rw [← mul_assoc,ENNReal.inv_mul_cancel hc0 hcT,one_mul]
65
+ _ ≤ _ := mul_le_mul_of_nonneg_left
66
+ (centeredMassPartialSum_selected_bound P (ℱ n) (D n) (hD n) (hDm n)
67
+ (N n) (J n) (hJ n) ε hε) (show 0 ≤ c⁻¹ from zero_le)
68
+ have ht : Tendsto (fun n => c⁻¹*ENNReal.ofReal
69
+ (∫ ω, ∑ i ∈ Finset.range (N n), D n i ω^2 ∂P)) atTop (𝓝 0) := by
70
+ simpa only [ENNReal.ofReal_zero,mul_zero] using
71
+ ENNReal.Tendsto.const_mul (ENNReal.tendsto_ofReal hE)
72
+ (Or.inr (ENNReal.inv_ne_top.mpr hc0))
73
+ simpa only [Pi.zero_apply,sub_zero,Real.norm_eq_abs] using
74
+ tendsto_of_tendsto_of_tendsto_of_le_of_le tendsto_const_nhds ht
75
+ (fun _ => bot_le) hb
76
+
77
+ end SLEExactGauge
78
+
79
+ end
80
+
81
+ end OAI
lean/OAI/Probability/SLE/Mass/MassCompensatorVariance.lean ADDED
@@ -0,0 +1,192 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Mass.MassCompensatorMesh
2
+ import Mathlib.Probability.Martingale.Centering
3
+ import Mathlib.Probability.Martingale.OptionalStopping
4
+ import Mathlib.Probability.CondVar
5
+
6
+ namespace OAI
7
+
8
+ /-! Orthogonality and variance bounds for the discrete potential
9
+ compensator used in the prescribed moment coefficients. -/
10
+
11
+ noncomputable section
12
+ open Set Filter MeasureTheory ProbabilityTheory
13
+ open scoped Topology NNReal ENNReal
14
+
15
+ namespace SLEExactGauge
16
+
17
+ variable {Ω : Type*} [mΩ : MeasurableSpace Ω] (P : Measure Ω) [IsProbabilityMeasure P]
18
+
19
+ section Centered
20
+ variable (m : MeasurableSpace Ω) (hm : m ≤ mΩ)
21
+
22
+ include hm in
23
+ lemma centered_mass_increment_condExp (X : Ω → ℝ) (hX : MemLp X 2 P) :
24
+ P[X-P[X|m]|m] =ᵐ[P] 0 := by
25
+ have hi := hX.integrable one_le_two
26
+ have h := condExp_sub hi (integrable_condExp (μ := P) (m := m) (f := X)) m
27
+ rw [condExp_of_stronglyMeasurable hm stronglyMeasurable_condExp integrable_condExp] at h
28
+ simpa only [sub_self] using h
29
+
30
+ include hm in
31
+ lemma integral_mul_centered_mass_increment
32
+ (X Y : Ω → ℝ) (hX : MemLp X 2 P) (hY : MemLp Y 2 P)
33
+ (hYm : StronglyMeasurable[m] Y) :
34
+ (∫ ω, Y ω*(X ω-P[X|m] ω) ∂P)=0 := by
35
+ have hZ : MemLp (X-P[X|m]) 2 P := hX.sub (hX.condExp one_le_two)
36
+ have hprod : Integrable (Y*(X-P[X|m])) P := memLp_one_iff_integrable.mp (hY.mul hZ)
37
+ have he := condExp_mul_of_stronglyMeasurable_left hYm hprod (hZ.integrable one_le_two)
38
+ have hz := centered_mass_increment_condExp (mΩ := mΩ) P m hm X hX
39
+ have he0 : P[Y*(X-P[X|m])|m] =ᵐ[P] 0 := by
40
+ filter_upwards [he,hz] with ω hp hz
41
+ simp only [Pi.mul_apply,Pi.zero_apply,hz,mul_zero] at hp ⊢
42
+ exact hp
43
+ calc
44
+ _ = ∫ ω, P[Y*(X-P[X|m])|m] ω ∂P := (integral_condExp hm).symm
45
+ _ = 0 := by simpa only [Pi.zero_apply,integral_zero] using integral_congr_ae he0
46
+
47
+ include hm in
48
+ lemma centered_mass_increment_variance_le (X : Ω → ℝ) (hX : MemLp X 2 P) :
49
+ (∫ ω, (X ω-P[X|m] ω)^2 ∂P) ≤ ∫ ω, X ω^2 ∂P := by
50
+ have hZ : Integrable (fun ω => (X ω-P[X|m] ω)^2) P :=
51
+ (hX.sub (hX.condExp one_le_two)).integrable_sq
52
+ have he := setIntegral_condVar (hm := hm) hZ (MeasurableSet.univ : MeasurableSet[m] univ)
53
+ simp only [Measure.restrict_univ] at he
54
+ rw [← he]
55
+ calc
56
+ _ ≤ ∫ ω, P[X^2|m] ω ∂P :=
57
+ integral_mono_ae integrable_condVar integrable_condExp (condVar_ae_le_condExp_sq hm hX)
58
+ _ = _ := integral_condExp hm
59
+
60
+ end Centered
61
+
62
+ lemma martingale_square_submartingale
63
+ {ι : Type*} [Preorder ι] (ℱ : Filtration ι mΩ)
64
+ (M : ι → Ω → ℝ) (hM : Martingale M ℱ P) (h2 : ∀ i, MemLp (M i) 2 P) :
65
+ Submartingale (fun i ω => M i ω^2) ℱ P := by
66
+ refine ⟨fun i => (hM.stronglyMeasurable i).pow 2,?_,fun i => (h2 i).integrable_sq⟩
67
+ intro i j hij
68
+ have hv := condVar_ae_eq_condExp_sq_sub_sq_condExp (ℱ.le i) (h2 j)
69
+ have hn : 0 ≤ᵐ[P] condVar (ℱ i) (M j) P :=
70
+ condExp_nonneg (ae_of_all _ (fun ω => sq_nonneg (M j ω-P[M j|ℱ i] ω)))
71
+ filter_upwards [hv,hn,hM.condExp_ae_eq hij] with ω hv hn he
72
+ simp only [Pi.sub_apply,Pi.pow_apply] at hv
73
+ rw [he] at hv
74
+ change 0 ≤ condVar (ℱ i) (M j) P ω at hn
75
+ change condVar (ℱ i) (M j) P ω = P[fun ω => M j ω^2|ℱ i] ω - M i ω^2 at hv
76
+ linarith
77
+
78
+ lemma martingale_square_maximal_ineq
79
+ (ℱ : Filtration ℕ mΩ) (M : ℕ → Ω → ℝ)
80
+ (hM : Martingale M ℱ P) (h2 : ∀ i, MemLp (M i) 2 P)
81
+ (ε : ℝ≥0) (N : ℕ) :
82
+ (ε:ℝ≥0∞) * P {ω | (ε:ℝ) ≤ (Finset.range (N+1)).sup'
83
+ Finset.nonempty_range_add_one (fun j => M j ω^2)} ≤
84
+ ENNReal.ofReal (∫ ω, M N ω^2 ∂P) := by
85
+ have hsub := martingale_square_submartingale P ℱ M hM h2
86
+ have h := maximal_ineq hsub (fun i ω => sq_nonneg (M i ω)) (ε := ε) N
87
+ refine h.trans (ENNReal.ofReal_le_ofReal ?_)
88
+ exact setIntegral_le_integral (h2 N).integrable_sq (ae_of_all _ (fun ω => sq_nonneg (M N ω)))
89
+
90
+ noncomputable def centeredMassPartialSum (ℱ : Filtration ℕ mΩ) (D : ℕ → Ω → ℝ)
91
+ (n : ℕ) (ω : Ω) : ℝ := ∑ i ∈ Finset.range n, (D i ω - condExp (ℱ i) P (D i) ω)
92
+
93
+ omit [IsProbabilityMeasure P] in
94
+ lemma centeredMassPartialSum_memLp (ℱ : Filtration ℕ mΩ) (D : ℕ → Ω → ℝ)
95
+ (hD : ∀ i, MemLp (D i) 2 P) (n : ℕ) :
96
+ MemLp (centeredMassPartialSum P ℱ D n) 2 P :=
97
+ memLp_finsetSum _ (fun i _ => (hD i).sub ((hD i).condExp one_le_two))
98
+
99
+ omit [IsProbabilityMeasure P] in
100
+ lemma centeredMassPartialSum_stronglyMeasurable
101
+ (ℱ : Filtration ℕ mΩ) (D : ℕ → Ω → ℝ)
102
+ (hD : ∀ i, StronglyMeasurable[ℱ (i+1)] (D i)) (n : ℕ) :
103
+ StronglyMeasurable[ℱ n] (centeredMassPartialSum P ℱ D n) := by
104
+ apply Finset.stronglyMeasurable_fun_sum
105
+ intro i hi
106
+ have hle : i+1 ≤ n := Nat.succ_le_of_lt (Finset.mem_range.mp hi)
107
+ exact ((hD i).mono (ℱ.mono hle)).sub
108
+ (stronglyMeasurable_condExp.mono (ℱ.mono (Nat.le_of_lt (Finset.mem_range.mp hi))))
109
+
110
+ lemma centeredMassPartialSum_variance
111
+ (ℱ : Filtration ℕ mΩ) (D : ℕ → Ω → ℝ)
112
+ (hD : ∀ i, MemLp (D i) 2 P)
113
+ (hDm : ∀ i, StronglyMeasurable[ℱ (i+1)] (D i)) (n : ℕ) :
114
+ (∫ ω, centeredMassPartialSum P ℱ D n ω^2 ∂P) =
115
+ ∑ i ∈ Finset.range n, ∫ ω, (D i ω-P[D i|ℱ i] ω)^2 ∂P := by
116
+ induction n with
117
+ | zero => simp [centeredMassPartialSum]
118
+ | succ n ih =>
119
+ have hS := centeredMassPartialSum_memLp P ℱ D hD n
120
+ have hX : MemLp (D n-P[D n|ℱ n]) 2 P := (hD n).sub ((hD n).condExp one_le_two)
121
+ have hSX : Integrable (fun ω => centeredMassPartialSum P ℱ D n ω*
122
+ (D n ω-P[D n|ℱ n] ω)) P := memLp_one_iff_integrable.mp (hS.mul hX)
123
+ have hcross := integral_mul_centered_mass_increment P (ℱ n) (ℱ.le n)
124
+ (D n) (centeredMassPartialSum P ℱ D n) (hD n) hS
125
+ (centeredMassPartialSum_stronglyMeasurable P ℱ D hDm n)
126
+ have he : (fun ω => centeredMassPartialSum P ℱ D (n+1) ω^2) =
127
+ (fun ω => centeredMassPartialSum P ℱ D n ω^2+
128
+ 2*(centeredMassPartialSum P ℱ D n ω*(D n ω-P[D n|ℱ n] ω))+
129
+ (D n ω-P[D n|ℱ n] ω)^2) := by
130
+ funext ω
131
+ simp only [centeredMassPartialSum,Finset.sum_range_succ]
132
+ ring
133
+ have hi₁ := integral_add (hS.integrable_sq.add (hSX.const_mul 2)) hX.integrable_sq
134
+ have hi₂ := integral_add hS.integrable_sq (hSX.const_mul 2)
135
+ simp only [Pi.add_apply,Pi.sub_apply] at hi₁ hi₂
136
+ rw [he,hi₁,hi₂,integral_const_mul,hcross,mul_zero,add_zero,ih,Finset.sum_range_succ]
137
+
138
+ lemma centeredMassPartialSum_variance_le
139
+ (ℱ : Filtration ℕ mΩ) (D : ℕ → Ω → ℝ)
140
+ (hD : ∀ i, MemLp (D i) 2 P)
141
+ (hDm : ∀ i, StronglyMeasurable[ℱ (i+1)] (D i)) (n : ℕ) :
142
+ (∫ ω, centeredMassPartialSum P ℱ D n ω^2 ∂P) ≤
143
+ ∫ ω, ∑ i ∈ Finset.range n, D i ω^2 ∂P := by
144
+ rw [centeredMassPartialSum_variance P ℱ D hD hDm n,
145
+ integral_finsetSum _ (fun i _ => (hD i).integrable_sq)]
146
+ exact Finset.sum_le_sum (fun i _ => centered_mass_increment_variance_le P (ℱ i) (ℱ.le i) (D i) (hD i))
147
+
148
+ lemma centeredMassPartialSum_martingale
149
+ (ℱ : Filtration ℕ mΩ) (D : ℕ → Ω → ℝ)
150
+ (hD : ∀ i, MemLp (D i) 2 P)
151
+ (hDm : ∀ i, StronglyMeasurable[ℱ (i+1)] (D i)) :
152
+ Martingale (centeredMassPartialSum P ℱ D) ℱ P := by
153
+ let A : ℕ → Ω → ℝ := fun n ω => ∑ i ∈ Finset.range n, D i ω
154
+ have hAm : StronglyAdapted ℱ A := by
155
+ intro n
156
+ apply Finset.stronglyMeasurable_fun_sum
157
+ intro i hi
158
+ exact (hDm i).mono (ℱ.mono (Nat.succ_le_of_lt (Finset.mem_range.mp hi)))
159
+ have hAI (n : ℕ) : Integrable (A n) P :=
160
+ (memLp_finsetSum _ (fun i _ => hD i)).integrable one_le_two
161
+ have hd (i : ℕ) : A (i+1)-A i=D i := by
162
+ funext ω
163
+ simp only [A,Finset.sum_range_succ,Pi.sub_apply,add_sub_cancel_left]
164
+ have he : martingalePart A ℱ P = centeredMassPartialSum P ℱ D := by
165
+ rw [martingalePart_eq_sum]
166
+ funext n ω
167
+ simp only [Pi.add_apply,Finset.sum_apply,Pi.sub_apply]
168
+ change A 0 ω+(∑ i ∈ Finset.range n,
169
+ ((A (i+1)-A i) ω-condExp (ℱ i) P (A (i+1)-A i) ω)) = _
170
+ simp only [hd]
171
+ simp only [A,Finset.range_zero,Finset.sum_empty,zero_add,centeredMassPartialSum]
172
+ simpa only [he] using martingale_martingalePart hAm hAI
173
+
174
+ /-- A maximal estimate valid at every selected grid index, without
175
+ requiring that the selected index itself be a stopping time. -/
176
+ theorem centeredMassPartialSum_maximal_error
177
+ (ℱ : Filtration ℕ mΩ) (D : ℕ → Ω → ℝ)
178
+ (hD : ∀ i, MemLp (D i) 2 P)
179
+ (hDm : ∀ i, StronglyMeasurable[ℱ (i+1)] (D i)) (ε : ℝ≥0) (N : ℕ) :
180
+ (ε:ℝ≥0∞)*P {ω | (ε:ℝ) ≤ (Finset.range (N+1)).sup'
181
+ Finset.nonempty_range_add_one (fun j => centeredMassPartialSum P ℱ D j ω^2)} ≤
182
+ ENNReal.ofReal (∫ ω, ∑ i ∈ Finset.range N, D i ω^2 ∂P) := by
183
+ exact (martingale_square_maximal_ineq P ℱ (centeredMassPartialSum P ℱ D)
184
+ (centeredMassPartialSum_martingale P ℱ D hD hDm)
185
+ (centeredMassPartialSum_memLp P ℱ D hD) ε N).trans
186
+ (ENNReal.ofReal_le_ofReal (centeredMassPartialSum_variance_le P ℱ D hD hDm N))
187
+
188
+ end SLEExactGauge
189
+
190
+ end
191
+
192
+ end OAI
lean/OAI/Probability/SLE/Mass/MassGridCutoffs.lean ADDED
@@ -0,0 +1,105 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Mass.MassGridOverlap
2
+ import OAI.Probability.SLE.Mass.LevelRadonMoments
3
+
4
+ namespace OAI
5
+
6
+ /-! Compact spatial test functions adapted to the mass grid. A fixed
7
+ compact cutoff keeps every enlarged grid cell inside the open half-plane. -/
8
+
9
+ noncomputable section
10
+ open Set Metric Filter MeasureTheory Classical
11
+ open scoped ENNReal Topology CompactlySupported
12
+
13
+ namespace SLEExactGauge.Multipoint
14
+
15
+ lemma exists_unit_compact_test_cutoff (K : Set upperHalfPlane) (hK : IsCompact K) :
16
+ ∃ f : C_c(upperHalfPlane,ℝ), (∀ z, 0 ≤ f z ∧ f z ≤ 1) ∧ ∀ z ∈ K, f z = 1 := by
17
+ let : LocallyCompactSpace upperHalfPlane := isOpen_upperHalfPlane.locallyCompactSpace
18
+ obtain ⟨f,hf,hfc,_,h01⟩ := exists_continuousMap_one_of_isCompact_subset_isOpen
19
+ hK isOpen_univ (subset_univ K)
20
+ exact ⟨⟨f,hfc⟩,h01,fun z hz => hf hz⟩
21
+
22
+ def massGridBump (r : ℝ) (i : ℤ×ℤ) : C(upperHalfPlane,ℝ) :=
23
+ ⟨fun z => max 0 (min 1 ((3*r-dist (z:ℂ) (coverGridCenter r i))/r)), by fun_prop⟩
24
+
25
+ def massGridCutoff (χ : C_c(upperHalfPlane,ℝ)) (r : ℝ) (i : ℤ×ℤ) :
26
+ C_c(upperHalfPlane,ℝ) := massGridBump r i • χ
27
+
28
+ lemma massGridBump_bounds (r : ℝ) (i : ℤ×ℤ) (z : upperHalfPlane) :
29
+ 0 ≤ massGridBump r i z ∧ massGridBump r i z ≤ 1 := by
30
+ exact ⟨le_max_left _ _, max_le (by norm_num) (min_le_left _ _)⟩
31
+
32
+ lemma massGridBump_eq_one {r : ℝ} (hr : 0 < r) (i : ℤ×ℤ) (z : upperHalfPlane)
33
+ (hz : dist (z:ℂ) (coverGridCenter r i) ≤ 2*r) : massGridBump r i z = 1 := by
34
+ have hh : 1 ≤ (3*r-dist (z:ℂ) (coverGridCenter r i))/r := (le_div_iff₀ hr).mpr (by linarith)
35
+ simp only [massGridBump,ContinuousMap.coe_mk,min_eq_left hh,max_eq_right (by norm_num : (0:ℝ)≤1)]
36
+
37
+ lemma massGridBump_eq_zero {r : ℝ} (hr : 0 < r) (i : ℤ×ℤ) (z : upperHalfPlane)
38
+ (hz : 3*r < dist (z:ℂ) (coverGridCenter r i)) : massGridBump r i z = 0 := by
39
+ have hh : (3*r-dist (z:ℂ) (coverGridCenter r i))/r ≤ 0 :=
40
+ div_nonpos_of_nonpos_of_nonneg (by linarith) hr.le
41
+ apply max_eq_left
42
+ exact (min_le_right _ _).trans hh
43
+
44
+ lemma massGridCutoff_bounds (χ : C_c(upperHalfPlane,ℝ))
45
+ (hχ : ∀ z, 0 ≤ χ z ∧ χ z ≤ 1) (r : ℝ) (i : ℤ×ℤ) (z : upperHalfPlane) :
46
+ 0 ≤ massGridCutoff χ r i z ∧ massGridCutoff χ r i z ≤ 1 := by
47
+ have hb := massGridBump_bounds r i z
48
+ change 0 ≤ massGridBump r i z * χ z ∧ massGridBump r i z * χ z ≤ 1
49
+ exact ⟨mul_nonneg hb.1 (hχ z).1,(mul_le_mul_of_nonneg_right hb.2 (hχ z).1).trans (by simpa only [one_mul] using (hχ z).2)⟩
50
+
51
+ lemma massGridCutoff_eq_one (χ : C_c(upperHalfPlane,ℝ)) {r : ℝ} (hr : 0 < r)
52
+ (i : ℤ×ℤ) (z : upperHalfPlane) (hχ : χ z = 1)
53
+ (hz : dist (z:ℂ) (coverGridCenter r i) ≤ 2*r) : massGridCutoff χ r i z = 1 := by
54
+ change massGridBump r i z * χ z = 1
55
+ rw [massGridBump_eq_one hr i z hz,hχ,one_mul]
56
+
57
+ lemma massGridCutoff_support (χ : C_c(upperHalfPlane,ℝ)) {r : ℝ} (hr : 0 < r)
58
+ (i : ℤ×ℤ) (z : ℂ) (hz : extendHalfPlaneTest (massGridCutoff χ r i) z ≠ 0) :
59
+ dist z (coverGridCenter r i) ≤ 3*r := by
60
+ by_cases hH : z ∈ upperHalfPlane
61
+ · by_contra h
62
+ have he := massGridBump_eq_zero hr i ⟨z,hH⟩ (lt_of_not_ge h)
63
+ apply hz
64
+ rw [show z = (⟨z,hH⟩ : upperHalfPlane).val from rfl,extendHalfPlaneTest_apply]
65
+ change massGridBump r i ⟨z,hH⟩ * χ ⟨z,hH⟩ = 0
66
+ rw [he,zero_mul]
67
+ · exact False.elim (hz (extendHalfPlaneTest_of_not_mem _ z hH))
68
+
69
+ lemma massGridCutoff_common_support (χ : C_c(upperHalfPlane,ℝ)) (r : ℝ) (i : ℤ×ℤ)
70
+ (z : ℂ) (hz : z ∉ (Subtype.val : upperHalfPlane → ℂ) '' tsupport χ) :
71
+ extendHalfPlaneTest (massGridCutoff χ r i) z = 0 := by
72
+ by_cases hH : z ∈ upperHalfPlane
73
+ · let x : upperHalfPlane := ⟨z,hH⟩
74
+ have hχ : χ x = 0 := image_eq_zero_of_notMem_tsupport (fun h => hz ⟨x,h,rfl⟩)
75
+ change extendHalfPlaneTest (massGridCutoff χ r i) x = 0
76
+ rw [extendHalfPlaneTest_apply]
77
+ change massGridBump r i x * χ x = 0
78
+ rw [hχ,mul_zero]
79
+ · exact extendHalfPlaneTest_of_not_mem _ z hH
80
+
81
+ lemma massGridCutoff_sum_bound (χ : C_c(upperHalfPlane,ℝ))
82
+ (hχ : ∀ z, 0 ≤ χ z ∧ χ z ≤ 1) {r : ℝ} (hr : 0 < r) (I : Finset (ℤ×ℤ))
83
+ (x y : ℂ) :
84
+ (∑ i ∈ I, ENNReal.ofReal (extendHalfPlaneTest (massGridCutoff χ r i) x) *
85
+ ENNReal.ofReal (extendHalfPlaneTest (massGridCutoff χ r i) y)) ≤
86
+ if dist x y ≤ 6*r then 81 else 0 := by
87
+ refine massGrid_cutoff_product_sum_le hr I
88
+ (fun i z => ENNReal.ofReal (extendHalfPlaneTest (massGridCutoff χ r i) z)) ?_ ?_ x y
89
+ · intro i z
90
+ apply ENNReal.ofReal_le_one.mpr
91
+ by_cases hH : z ∈ upperHalfPlane
92
+ · rw [show z = (⟨z,hH⟩ : upperHalfPlane).val from rfl,extendHalfPlaneTest_apply]
93
+ exact (massGridCutoff_bounds χ hχ r i ⟨z,hH⟩).2
94
+ · rw [extendHalfPlaneTest_of_not_mem _ z hH]
95
+ norm_num
96
+ · intro i z hz
97
+ apply massGridCutoff_support χ hr i z
98
+ intro he
99
+ exact hz (by rw [he,ENNReal.ofReal_zero])
100
+
101
+ end SLEExactGauge.Multipoint
102
+
103
+ end
104
+
105
+ end OAI
lean/OAI/Probability/SLE/Mass/MassGridOverlap.lean ADDED
@@ -0,0 +1,91 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Gauge.CoverGrid
2
+
3
+ namespace OAI
4
+
5
+ /-! A fixed overlap bound for planar mass cutoffs on the physical grid. -/
6
+
7
+ noncomputable section
8
+ open Set Metric Filter MeasureTheory Classical
9
+ open scoped ENNReal
10
+
11
+ namespace SLEExactGauge
12
+
13
+ lemma massGrid_coordinate_bounds {r x : ℝ} (hr : 0 < r) (i : ℤ)
14
+ (hi : |x-r*(i:ℝ)| ≤ 3*r) :
15
+ ⌊x/r⌋-4 ≤ i ∧ i ≤ ⌊x/r⌋+4 := by
16
+ have hf : r*(⌊x/r⌋:ℝ) ≤ x := by
17
+ have hh := mul_le_mul_of_nonneg_left (Int.floor_le (x/r)) hr.le
18
+ rwa [mul_div_cancel₀ _ hr.ne'] at hh
19
+ have hg : x < r*((⌊x/r⌋:ℝ)+1) := by
20
+ have hh := mul_lt_mul_of_pos_left (Int.lt_floor_add_one (x/r)) hr
21
+ rwa [mul_div_cancel₀ _ hr.ne'] at hh
22
+ have hlo : ((⌊x/r⌋-4:ℤ):ℝ) ≤ (i:ℝ) := by
23
+ push_cast
24
+ nlinarith [abs_le.mp hi]
25
+ have hhi : (i:ℝ) ≤ ((⌊x/r⌋+4:ℤ):ℝ) := by
26
+ push_cast
27
+ nlinarith [abs_le.mp hi]
28
+ exact ⟨by exact_mod_cast hlo,by exact_mod_cast hhi⟩
29
+
30
+ lemma massGrid_nearby_card_le {r : ℝ} (hr : 0 < r) (I : Finset (ℤ×ℤ)) (z : ℂ) :
31
+ (I.filter (fun ij => dist z (coverGridCenter r ij) ≤ 3*r)).card ≤ 81 := by
32
+ let J := (Finset.Icc (⌊z.re/r⌋-4) (⌊z.re/r⌋+4)) ×ˢ
33
+ (Finset.Icc (⌊z.im/r⌋-4) (⌊z.im/r⌋+4))
34
+ have hsub : I.filter (fun ij => dist z (coverGridCenter r ij) ≤ 3*r) ⊆ J := by
35
+ intro ij hij
36
+ have hd := (Finset.mem_filter.mp hij).2
37
+ have hre : |z.re-r*(ij.1:ℝ)| ≤ 3*r := by
38
+ have h := (Complex.abs_re_le_norm (z-coverGridCenter r ij)).trans
39
+ (by simpa only [dist_eq_norm] using hd)
40
+ simpa [coverGridCenter] using h
41
+ have him : |z.im-r*(ij.2:ℝ)| ≤ 3*r := by
42
+ have h := (Complex.abs_im_le_norm (z-coverGridCenter r ij)).trans
43
+ (by simpa only [dist_eq_norm] using hd)
44
+ simpa [coverGridCenter] using h
45
+ simpa only [J,Finset.mem_product,Finset.mem_Icc] using
46
+ And.intro (massGrid_coordinate_bounds hr ij.1 hre) (massGrid_coordinate_bounds hr ij.2 him)
47
+ have hcard : J.card = 81 := by
48
+ simp only [J,Finset.card_product,Int.card_Icc]
49
+ rw [show ⌊z.re/r⌋+4+1-(⌊z.re/r⌋-4) = (9:ℤ) by omega,
50
+ show ⌊z.im/r⌋+4+1-(⌊z.im/r⌋-4) = (9:ℤ) by omega]
51
+ rfl
52
+ exact (Finset.card_le_card hsub).trans_eq hcard
53
+
54
+ lemma massGrid_cutoff_product_sum_le {r : ℝ} (hr : 0 < r) (I : Finset (ℤ×ℤ))
55
+ (f : (ℤ×ℤ) → ℂ → ℝ≥0∞) (hf : ∀ i z, f i z ≤ 1)
56
+ (hs : ∀ i z, f i z ≠ 0 → dist z (coverGridCenter r i) ≤ 3*r)
57
+ (x y : ℂ) :
58
+ (∑ i ∈ I, f i x * f i y) ≤ if dist x y ≤ 6*r then 81 else 0 := by
59
+ by_cases hxy : dist x y ≤ 6*r
60
+ · rw [ite_eq_left hxy]
61
+ let J := I.filter (fun i => dist x (coverGridCenter r i) ≤ 3*r)
62
+ have he : (∑ i ∈ I, f i x * f i y) = ∑ i ∈ J, f i x * f i y := by
63
+ symm
64
+ apply Finset.sum_subset (Finset.filter_subset _ _)
65
+ intro i hi hij
66
+ have hx : f i x = 0 := by
67
+ by_contra h
68
+ exact hij (Finset.mem_filter.mpr ⟨hi,hs i x h⟩)
69
+ simp only [hx,zero_mul]
70
+ rw [he]
71
+ calc
72
+ _ ≤ ∑ _i ∈ J, (1 : ℝ≥0∞) :=
73
+ Finset.sum_le_sum (fun i _ => (mul_le_mul' (hf i x) (hf i y)).trans_eq (one_mul 1))
74
+ _ = J.card := by simp
75
+ _ ≤ 81 := by exact_mod_cast massGrid_nearby_card_le hr I x
76
+ · rw [ite_eq_right hxy]
77
+ apply le_of_eq
78
+ apply Finset.sum_eq_zero
79
+ intro i hi
80
+ by_cases hx : f i x = 0
81
+ · simp only [hx,zero_mul]
82
+ by_cases hy : f i y = 0
83
+ · simp only [hy,mul_zero]
84
+ exact False.elim (hxy ((dist_triangle_right x y (coverGridCenter r i)).trans
85
+ (by linarith [hs i x hx,hs i y hy])))
86
+
87
+ end SLEExactGauge
88
+
89
+ end
90
+
91
+ end OAI
lean/OAI/Probability/SLE/Mass/MassKernelUniqueness.lean ADDED
@@ -0,0 +1,51 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Mass.MassMartingaleUniqueness
2
+
3
+ namespace OAI
4
+
5
+ /-! Equal terminal remainder kernels yield a martingale difference; continuity
6
+ and increasing integrable masses then imply uniqueness. -/
7
+
8
+ noncomputable section
9
+ open MeasureTheory Filter
10
+ open scoped Topology NNReal
11
+
12
+ namespace SLEExactGauge
13
+
14
+ variable {Ω : Type*} [MeasurableSpace Ω] {P : Measure Ω} [IsFiniteMeasure P]
15
+ {ℱ : Filtration ℝ≥0 ‹MeasurableSpace Ω›}
16
+
17
+ lemma mass_difference_martingale_of_terminal_mean
18
+ (A B : ℝ≥0 → Ω → ℝ) (Z : Ω → ℝ) (hZ : Integrable Z P)
19
+ (hAm : StronglyAdapted ℱ A) (hBm : StronglyAdapted ℱ B)
20
+ (hAI : ∀ t, Integrable (A t) P) (hBI : ∀ t, Integrable (B t) P)
21
+ (hmean : ∀ t E, MeasurableSet[ℱ t] E →
22
+ (∫ ω in E, A t ω-B t ω ∂P) = ∫ ω in E, Z ω ∂P) :
23
+ Martingale (fun t ω => A t ω-B t ω) ℱ P := by
24
+ have he (t : ℝ≥0) : (fun ω => A t ω-B t ω) =ᵐ[P] P[Z | ℱ t] := by
25
+ apply ae_eq_condExp_of_forall_setIntegral_eq (ℱ.le t) hZ
26
+ (fun E _ _ => ((hAI t).sub (hBI t)).integrableOn)
27
+ (fun E hE _ => hmean t E hE)
28
+ exact ((hAm t).sub (hBm t)).aestronglyMeasurable
29
+ exact (martingale_condExp Z ℱ P).congr (hAm.sub hBm)
30
+ (fun t => (he t).symm)
31
+
32
+ theorem increasing_mass_unique_of_terminal_mean
33
+ (A B : ℝ≥0 → Ω → ℝ) (Z : Ω → ℝ) (hZ : Integrable Z P)
34
+ (hAm : StronglyAdapted ℱ A) (hBm : StronglyAdapted ℱ B)
35
+ (hAI : ∀ t, Integrable (A t) P) (hBI : ∀ t, Integrable (B t) P)
36
+ (hmean : ∀ t E, MeasurableSet[ℱ t] E →
37
+ (∫ ω in E, A t ω-B t ω ∂P) = ∫ ω in E, Z ω ∂P)
38
+ (hA : ∀ᵐ ω ∂P, Monotone (fun t => A t ω))
39
+ (hB : ∀ᵐ ω ∂P, Monotone (fun t => B t ω))
40
+ (hA0 : A 0 =ᵐ[P] 0) (hB0 : B 0 =ᵐ[P] 0)
41
+ (hcont : ∀ᵐ ω ∂P, Continuous (fun t => A t ω-B t ω)) :
42
+ ∀ᵐ ω ∂P, ∀ t, A t ω = B t ω :=
43
+ increasing_mass_martingale_indistinguishable A B
44
+ (mass_difference_martingale_of_terminal_mean A B Z hZ hAm hBm hAI hBI hmean)
45
+ hA hB hA0 hB0 hAI hBI hcont
46
+
47
+ end SLEExactGauge
48
+
49
+ end
50
+
51
+ end OAI
lean/OAI/Probability/SLE/Mass/MassMartingaleTesting.lean ADDED
@@ -0,0 +1,75 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Mass.MassUniquenessSeparation
2
+ import Mathlib.Probability.Martingale.Basic
3
+ import Mathlib.MeasureTheory.Function.ConditionalExpectation.PullOut
4
+
5
+ namespace OAI
6
+
7
+ /-! Bounded predictable testing of the increments in the mass uniqueness proof. -/
8
+
9
+ noncomputable section
10
+ open MeasureTheory Filter
11
+ open scoped Topology NNReal
12
+
13
+ namespace SLEExactGauge
14
+
15
+ lemma massSeparationTest_continuous : Continuous massSeparationTest :=
16
+ continuous_iff_continuousAt.mpr (fun x => (massSeparationTest_hasDerivAt x).continuousAt)
17
+
18
+ lemma massSeparationSlope_continuous : Continuous massSeparationSlope :=
19
+ continuous_iff_continuousAt.mpr (fun x => (massSeparationSlope_hasDerivAt x).continuousAt)
20
+
21
+ variable {Ω : Type*} [MeasurableSpace Ω] {P : Measure Ω} [IsFiniteMeasure P]
22
+ {ℱ : Filtration ℝ≥0 ‹MeasurableSpace Ω›} {M : ℝ≥0 → Ω → ℝ}
23
+
24
+ omit [IsFiniteMeasure P] in
25
+ lemma martingale_mass_test_integrable (hM : Martingale M ℱ P) (t : ℝ≥0) :
26
+ Integrable (fun ω => massSeparationTest (M t ω)) P := by
27
+ apply ((hM.integrable t).norm.const_mul 2).mono'
28
+ (massSeparationTest_continuous.comp_stronglyMeasurable
29
+ ((hM.stronglyMeasurable t).mono (ℱ.le t))).aestronglyMeasurable
30
+ filter_upwards [] with ω
31
+ simpa only [Real.norm_eq_abs,massSeparationTest_zero,sub_zero] using
32
+ massSeparationTest_lipschitz 0 (M t ω)
33
+
34
+ omit [IsFiniteMeasure P] in
35
+ lemma martingale_mass_weighted_increment_integrable (hM : Martingale M ℱ P)
36
+ (s t : ℝ≥0) :
37
+ Integrable (fun ω => massSeparationSlope (M s ω)*(M t ω-M s ω)) P := by
38
+ exact ((hM.integrable t).sub (hM.integrable s)).bdd_mul
39
+ (massSeparationSlope_continuous.comp_stronglyMeasurable
40
+ ((hM.stronglyMeasurable s).mono (ℱ.le s))).aestronglyMeasurable
41
+ (ae_of_all _ (fun ω => by simpa only [Real.norm_eq_abs] using
42
+ massSeparationSlope_abs_le (M s ω)))
43
+
44
+ lemma martingale_mass_weighted_increment_mean (hM : Martingale M ℱ P)
45
+ {s t : ℝ≥0} (hst : s ≤ t) :
46
+ (∫ ω, massSeparationSlope (M s ω)*(M t ω-M s ω) ∂P) = 0 := by
47
+ have hg := (hM.integrable t).sub (hM.integrable s)
48
+ have hfg := martingale_mass_weighted_increment_integrable hM s t
49
+ have hCE : P[(fun ω => M t ω-M s ω) | ℱ s] =ᵐ[P] 0 := by
50
+ have hsub := condExp_sub (hM.integrable t) (hM.integrable s) (ℱ s)
51
+ have hs : P[M s | ℱ s] = M s :=
52
+ condExp_of_stronglyMeasurable (ℱ.le s) (hM.stronglyMeasurable s) (hM.integrable s)
53
+ filter_upwards [hsub,hM.condExp_ae_eq hst] with ω hω htω
54
+ simp only [Pi.sub_apply,hs,htω,sub_self,Pi.zero_apply] at hω ⊢
55
+ exact hω
56
+ have hpull := condExp_mul_of_stronglyMeasurable_left
57
+ (massSeparationSlope_continuous.comp_stronglyMeasurable (hM.stronglyMeasurable s)) hfg hg
58
+ calc
59
+ _ = ∫ ω, P[(fun ω => massSeparationSlope (M s ω)*(M t ω-M s ω)) | ℱ s] ω ∂P :=
60
+ (integral_condExp (ℱ.le s)).symm
61
+ _ = 0 := by
62
+ have he : P[(fun ω => massSeparationSlope (M s ω)*(M t ω-M s ω)) | ℱ s] =ᵐ[P] 0 := by
63
+ filter_upwards [hpull,hCE] with ω hp hc
64
+ change P[(fun ω => massSeparationSlope (M s ω)*(M t ω-M s ω)) | ℱ s] ω =
65
+ massSeparationSlope (M s ω)*P[(fun ω => M t ω-M s ω) | ℱ s] ω at hp
66
+ change P[(fun ω => M t ω-M s ω) | ℱ s] ω = 0 at hc
67
+ simpa only [hc,mul_zero,Pi.zero_apply] using hp
68
+ rw [integral_congr_ae he]
69
+ simp
70
+
71
+ end SLEExactGauge
72
+
73
+ end
74
+
75
+ end OAI
lean/OAI/Probability/SLE/Mass/MassMartingaleUniqueness.lean ADDED
@@ -0,0 +1,123 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Mass.MassUniquenessMesh
2
+ import OAI.Probability.SLE.Mass.MassMartingaleTesting
3
+ import Mathlib.MeasureTheory.Integral.DominatedConvergence
4
+ import Mathlib.Topology.DenseEmbedding
5
+
6
+ namespace OAI
7
+
8
+ /-! Uniqueness of a continuous mass process from its integrable increasing
9
+ variation and martingale difference. No second moment is imposed on a competing
10
+ mass construction. -/
11
+
12
+ noncomputable section
13
+ open Set Filter MeasureTheory
14
+ open scoped Topology NNReal
15
+
16
+ namespace SLEExactGauge
17
+
18
+ variable {Ω : Type*} [MeasurableSpace Ω] {P : Measure Ω} [IsFiniteMeasure P]
19
+ {ℱ : Filtration ℝ≥0 ‹MeasurableSpace Ω›} (A B : ℝ≥0 → Ω → ℝ)
20
+
21
+ /-- A continuous martingale which is the difference of two increasing processes
22
+ starting at zero vanishes, using only integrability of the two endpoint masses. -/
23
+ theorem increasing_mass_martingale_eq_at
24
+ (hM : Martingale (fun t ω => A t ω-B t ω) ℱ P)
25
+ (hA : ∀ᵐ ω ∂P, Monotone (fun t => A t ω))
26
+ (hB : ∀ᵐ ω ∂P, Monotone (fun t => B t ω))
27
+ (hA0 : A 0 =ᵐ[P] 0) (hB0 : B 0 =ᵐ[P] 0)
28
+ (T : ℝ≥0) (hAI : Integrable (A T) P) (hBI : Integrable (B T) P)
29
+ (hcont : ∀ᵐ ω ∂P, ContinuousOn (fun t => A t ω-B t ω) (Icc 0 T)) :
30
+ A T =ᵐ[P] B T := by
31
+ let M : ℝ≥0 → Ω → ℝ := fun t ω => A t ω-B t ω
32
+ let X : ℕ → Ω → ℝ := fun n ω =>
33
+ massPartitionRemainder (fun i => M (massTimeMesh T n i) ω) (n+1)
34
+ have hXint (n : ℕ) : Integrable (X n) P := by
35
+ have hsum : Integrable (fun ω => ∑ i ∈ Finset.range (n+1),
36
+ massSeparationSlope (M (massTimeMesh T n i) ω)*
37
+ (M (massTimeMesh T n (i+1)) ω-M (massTimeMesh T n i) ω)) P :=
38
+ integrable_finsetSum _ (fun i _ =>
39
+ martingale_mass_weighted_increment_integrable hM _ _)
40
+ exact ((martingale_mass_test_integrable hM _).sub
41
+ (martingale_mass_test_integrable hM _)).sub hsum
42
+ have hXmean (n : ℕ) : (∫ ω, X n ω ∂P) = ∫ ω, massSeparationTest (M T ω) ∂P := by
43
+ have hsum (i : ℕ) := martingale_mass_weighted_increment_integrable hM
44
+ (massTimeMesh T n i) (massTimeMesh T n (i+1))
45
+ change (∫ ω, massSeparationTest (M (massTimeMesh T n (n+1)) ω)-
46
+ massSeparationTest (M (massTimeMesh T n 0) ω)-
47
+ ∑ i ∈ Finset.range (n+1), massSeparationSlope (M (massTimeMesh T n i) ω)*
48
+ (M (massTimeMesh T n (i+1)) ω-M (massTimeMesh T n i) ω) ∂P) = _
49
+ rw [massTimeMesh_end,massTimeMesh_zero,
50
+ integral_sub (f := fun ω => massSeparationTest (M T ω)-massSeparationTest (M 0 ω))
51
+ (g := fun ω => ∑ i ∈ Finset.range (n+1), massSeparationSlope (M (massTimeMesh T n i) ω)*
52
+ (M (massTimeMesh T n (i+1)) ω-M (massTimeMesh T n i) ω))
53
+ ((martingale_mass_test_integrable hM T).sub
54
+ (martingale_mass_test_integrable hM 0)) (integrable_finsetSum _ (fun i _ => hsum i)),
55
+ integral_sub (f := fun ω => massSeparationTest (M T ω))
56
+ (g := fun ω => massSeparationTest (M 0 ω))
57
+ (martingale_mass_test_integrable hM T) (martingale_mass_test_integrable hM 0),
58
+ integral_finsetSum _ (fun i _ => hsum i)]
59
+ have hzero : (fun ω => massSeparationTest (M 0 ω)) =ᵐ[P] 0 := by
60
+ filter_upwards [hA0,hB0] with ω ha hb
61
+ simp only [M,ha,hb,Pi.zero_apply,sub_self,massSeparationTest_zero]
62
+ have hmeans : (∑ i ∈ Finset.range (n+1), ∫ ω,
63
+ massSeparationSlope (M (massTimeMesh T n i) ω)*
64
+ (M (massTimeMesh T n (i+1)) ω-M (massTimeMesh T n i) ω) ∂P) = 0 := by
65
+ apply Finset.sum_eq_zero
66
+ intro i _
67
+ exact martingale_mass_weighted_increment_mean hM (massTimeMesh_mono T n (Nat.le_succ i))
68
+ simp only [M] at hmeans
69
+ rw [integral_congr_ae hzero,hmeans]
70
+ simp
71
+ have hbound (n : ℕ) : ∀ᵐ ω ∂P, ‖X n ω‖ ≤ 4*(A T ω+B T ω) := by
72
+ filter_upwards [hA,hB,hA0,hB0] with ω ha hb ha0 hb0
73
+ calc
74
+ _ ≤ 4*∑ i ∈ Finset.range (n+1),
75
+ |M (massTimeMesh T n (i+1)) ω-M (massTimeMesh T n i) ω| := by
76
+ simpa only [X,Real.norm_eq_abs] using massPartitionRemainder_linear
77
+ (fun i => M (massTimeMesh T n i) ω) (n+1)
78
+ _ ≤ 4*((A T ω-A 0 ω)+(B T ω-B 0 ω)) :=
79
+ mul_le_mul_of_nonneg_left (massDifference_mesh_variation
80
+ (fun t => A t ω) (fun t => B t ω) ha hb T n) (by norm_num)
81
+ _ = _ := by simp only [ha0,hb0,Pi.zero_apply,sub_zero]
82
+ have hlim : ∀ᵐ ω ∂P, Tendsto (fun n => X n ω) atTop (𝓝 0) := by
83
+ filter_upwards [hA,hB,hcont] with ω ha hb hc
84
+ exact massDifference_mesh_remainder_tendsto (fun t => A t ω) (fun t => B t ω) ha hb T hc
85
+ have hI := tendsto_integral_of_dominated_convergence (fun ω => 4*(A T ω+B T ω))
86
+ (fun n => (hXint n).aestronglyMeasurable) ((hAI.add hBI).const_mul 4) hbound hlim
87
+ simp only [integral_zero,hXmean] at hI
88
+ have htest0 : (∫ ω, massSeparationTest (M T ω) ∂P) = 0 :=
89
+ tendsto_nhds_unique tendsto_const_nhds hI
90
+ have hae := (integral_eq_zero_iff_of_nonneg
91
+ (fun ω => massSeparationTest_nonneg (M T ω))
92
+ (martingale_mass_test_integrable hM T)).mp htest0
93
+ filter_upwards [hae] with ω hω
94
+ exact sub_eq_zero.mp ((massSeparationTest_eq_zero (M T ω)).mp hω)
95
+
96
+ /-- The fixed-time result holds simultaneously at every time by continuity and
97
+ a countable dense family of deterministic times. -/
98
+ theorem increasing_mass_martingale_indistinguishable
99
+ (hM : Martingale (fun t ω => A t ω-B t ω) ℱ P)
100
+ (hA : ∀ᵐ ω ∂P, Monotone (fun t => A t ω))
101
+ (hB : ∀ᵐ ω ∂P, Monotone (fun t => B t ω))
102
+ (hA0 : A 0 =ᵐ[P] 0) (hB0 : B 0 =ᵐ[P] 0)
103
+ (hAI : ∀ T, Integrable (A T) P) (hBI : ∀ T, Integrable (B T) P)
104
+ (hcont : ∀ᵐ ω ∂P, Continuous (fun t => A t ω-B t ω)) :
105
+ ∀ᵐ ω ∂P, ∀ t, A t ω = B t ω := by
106
+ have heq (t : ℝ≥0) : A t =ᵐ[P] B t :=
107
+ increasing_mass_martingale_eq_at A B hM hA hB hA0 hB0 t (hAI t) (hBI t)
108
+ (hcont.mono (fun _ h => h.continuousOn))
109
+ have hcount : ∀ᵐ ω ∂P, ∀ n : ℕ,
110
+ A (TopologicalSpace.denseSeq ℝ≥0 n) ω = B (TopologicalSpace.denseSeq ℝ≥0 n) ω :=
111
+ ae_all_iff.mpr (fun n => heq _)
112
+ filter_upwards [hcount,hcont] with ω he hc
113
+ have hfun : (fun t => A t ω-B t ω) = fun _ => 0 :=
114
+ (TopologicalSpace.denseRange_denseSeq ℝ≥0).equalizer hc continuous_const
115
+ (funext (fun n => sub_eq_zero.mpr (he n)))
116
+ intro t
117
+ exact sub_eq_zero.mp (congr_fun hfun t)
118
+
119
+ end SLEExactGauge
120
+
121
+ end
122
+
123
+ end OAI
lean/OAI/Probability/SLE/Mass/MassPotentialCompensator.lean ADDED
@@ -0,0 +1,57 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Mass.MassCompensatorVariance
2
+
3
+ namespace OAI
4
+
5
+ /-! A remaining-mass potential determines the predictable mass increments. -/
6
+
7
+ noncomputable section
8
+ open Set Filter MeasureTheory ProbabilityTheory
9
+ open scoped Topology NNReal ENNReal
10
+
11
+ namespace SLEExactGauge
12
+
13
+ variable {Ω : Type*} [mΩ : MeasurableSpace Ω] (P : Measure Ω) [IsProbabilityMeasure P]
14
+
15
+ /-- The difference of the current potential and the one-step averaged
16
+ future potential is the conditional expectation of the mass increment. -/
17
+ theorem remainingPotential_increment
18
+ (ℱ : Filtration ℕ mΩ) (A V : ℕ → Ω → ℝ) (L : Ω → ℝ)
19
+ (hA : StronglyAdapted ℱ A) (hAI : ∀ i, Integrable (A i) P) (hLI : Integrable L P)
20
+ (hV : ∀ i, V i =ᵐ[P] P[L-A i|ℱ i]) (i : ℕ) :
21
+ V i-P[V (i+1)|ℱ i] =ᵐ[P] P[A (i+1)-A i|ℱ i] := by
22
+ have hnext := (condExp_congr_ae (m := ℱ i) (hV (i+1))).trans
23
+ (condExp_condExp_of_le (ℱ.mono (Nat.le_succ i)) (ℱ.le (i+1)))
24
+ have hcur := (hV i).trans (condExp_sub hLI (hAI i) (ℱ i))
25
+ have hnext' := hnext.trans (condExp_sub hLI (hAI (i+1)) (ℱ i))
26
+ have hinc := condExp_sub (hAI (i+1)) (hAI i) (ℱ i)
27
+ have hz := condExp_of_stronglyMeasurable (ℱ.le i) (hA i) (hAI i)
28
+ filter_upwards [hcur,hnext',hinc] with ω hc hn hi
29
+ simp only [Pi.sub_apply,hz] at hc hn hi ⊢
30
+ linarith
31
+
32
+ omit [IsProbabilityMeasure P] in
33
+ /-- Pathwise telescoping after identifying each predictable increment. -/
34
+ lemma predictable_mass_sum_eq
35
+ (ℱ : Filtration ℕ mΩ) (A : ℕ → Ω → ℝ)
36
+ (q : ℕ → Ω → ℝ)
37
+ (hq : ∀ i, q i =ᵐ[P] P[A (i+1)-A i|ℱ i]) (N : ℕ) :
38
+ (fun ω => ∑ i ∈ Finset.range N, q i ω) =ᵐ[P]
39
+ fun ω => A N ω-A 0 ω-centeredMassPartialSum P ℱ
40
+ (fun i => A (i+1)-A i) N ω := by
41
+ filter_upwards [ae_all_iff.mpr hq] with ω hω
42
+ simp only [centeredMassPartialSum,Pi.sub_apply]
43
+ have hs := Finset.sum_sub_distrib (s := Finset.range N)
44
+ (f := fun i => A (i+1) ω-A i ω)
45
+ (g := fun i => condExp (ℱ i) P (A (i+1)-A i) ω)
46
+ rw [Finset.sum_range_sub (fun i => A i ω) N] at hs
47
+ have hq' : (∑ i ∈ Finset.range N, q i ω) =
48
+ ∑ i ∈ Finset.range N, condExp (ℱ i) P (A (i+1)-A i) ω :=
49
+ Finset.sum_congr rfl (fun i _ => hω i)
50
+ rw [hq']
51
+ linarith
52
+
53
+ end SLEExactGauge
54
+
55
+ end
56
+
57
+ end OAI
lean/OAI/Probability/SLE/Mass/MassUniquenessMesh.lean ADDED
@@ -0,0 +1,81 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Mass.MassUniquenessPartitions
2
+ import Mathlib.Topology.Instances.NNReal.Lemmas
3
+ import Mathlib.Topology.UniformSpace.HeineCantor
4
+
5
+ namespace OAI
6
+
7
+ /-! Uniform finite time partitions used in the continuous-mass uniqueness proof. -/
8
+
9
+ noncomputable section
10
+ open Set Filter
11
+ open scoped Topology NNReal
12
+
13
+ namespace SLEExactGauge
14
+
15
+ def massTimeMesh (T : ℝ≥0) (n i : ℕ) : ℝ≥0 := T*(i:ℝ≥0)/(n+1:ℝ≥0)
16
+
17
+ @[simp] lemma massTimeMesh_zero (T : ℝ≥0) (n : ℕ) : massTimeMesh T n 0 = 0 := by
18
+ simp [massTimeMesh]
19
+
20
+ @[simp] lemma massTimeMesh_end (T : ℝ≥0) (n : ℕ) : massTimeMesh T n (n+1) = T := by
21
+ simp [massTimeMesh]
22
+
23
+ lemma massTimeMesh_mono (T : ℝ≥0) (n : ℕ) : Monotone (massTimeMesh T n) := by
24
+ intro i j hij
25
+ exact div_le_div_of_nonneg_right
26
+ (mul_le_mul_of_nonneg_left (by exact_mod_cast hij) (show 0 ≤ T from zero_le))
27
+ (by positivity)
28
+
29
+ lemma massTimeMesh_mem (T : ℝ≥0) (n i : ℕ) (hi : i ≤ n+1) :
30
+ massTimeMesh T n i ∈ Icc 0 T := by
31
+ exact ⟨zero_le,(massTimeMesh_mono T n hi).trans_eq (massTimeMesh_end T n)⟩
32
+
33
+ lemma massTimeMesh_dist (T : ℝ≥0) (n i : ℕ) :
34
+ dist (massTimeMesh T n (i+1)) (massTimeMesh T n i) = (T:ℝ)/(n+1:ℝ) := by
35
+ rw [NNReal.dist_eq]
36
+ simp only [massTimeMesh,NNReal.coe_div,NNReal.coe_mul,NNReal.coe_natCast,NNReal.coe_add,
37
+ NNReal.coe_one,Nat.cast_add,Nat.cast_one]
38
+ rw [show (T:ℝ)*(i+1:ℝ)/(n+1)-(T:ℝ)*(i:ℝ)/(n+1) = T/(n+1) by ring,
39
+ abs_of_nonneg (by positivity)]
40
+
41
+ lemma massTimeMesh_small_increments (T : ℝ≥0) (f : ℝ≥0 → ℝ)
42
+ (hf : ContinuousOn f (Icc 0 T)) :
43
+ ∀ ε : ℝ, 0 < ε → ∀ᶠ n in atTop,
44
+ ∀ i < n+1, |f (massTimeMesh T n (i+1))-f (massTimeMesh T n i)| ≤ ε := by
45
+ intro ε hε
46
+ obtain ⟨δ,hδ,hfδ⟩ := Metric.uniformContinuousOn_iff.mp
47
+ (isCompact_Icc.uniformContinuousOn_of_continuous hf) ε hε
48
+ have hlim : Tendsto (fun n : ℕ => (T:ℝ)/(n+1:ℝ)) atTop (𝓝 0) := by
49
+ simpa only [mul_one_div,mul_zero] using
50
+ (tendsto_one_div_add_atTop_nhds_zero_nat (𝕜 := ℝ)).const_mul (T:ℝ)
51
+ filter_upwards [hlim.eventually (gt_mem_nhds hδ)] with n hn i hi
52
+ have h := hfδ (massTimeMesh T n (i+1)) (massTimeMesh_mem T n (i+1) (by omega))
53
+ (massTimeMesh T n i) (massTimeMesh_mem T n i (by omega))
54
+ (by simpa only [massTimeMesh_dist] using hn)
55
+ exact le_of_lt (by simpa only [Real.dist_eq] using h)
56
+
57
+ lemma massDifference_mesh_variation (A B : ℝ≥0 → ℝ)
58
+ (hA : Monotone A) (hB : Monotone B) (T : ℝ≥0) (n : ℕ) :
59
+ (∑ i ∈ Finset.range (n+1),
60
+ |(A (massTimeMesh T n (i+1))-B (massTimeMesh T n (i+1)))-
61
+ (A (massTimeMesh T n i)-B (massTimeMesh T n i))|) ≤
62
+ (A T-A 0)+(B T-B 0) := by
63
+ simpa only [Function.comp_def,massTimeMesh_zero,massTimeMesh_end] using
64
+ massDifference_partition_variation (A ∘ massTimeMesh T n) (B ∘ massTimeMesh T n)
65
+ (hA.comp (massTimeMesh_mono T n)) (hB.comp (massTimeMesh_mono T n)) (n+1)
66
+
67
+ lemma massDifference_mesh_remainder_tendsto (A B : ℝ≥0 → ℝ)
68
+ (hA : Monotone A) (hB : Monotone B) (T : ℝ≥0)
69
+ (hcont : ContinuousOn (fun t => A t-B t) (Icc 0 T)) :
70
+ Tendsto (fun n => massPartitionRemainder
71
+ (fun i => A (massTimeMesh T n i)-B (massTimeMesh T n i)) (n+1)) atTop (𝓝 0) := by
72
+ exact massPartitionRemainder_tendsto_zero _ _ ((A T-A 0)+(B T-B 0))
73
+ (add_nonneg (sub_nonneg.mpr (hA zero_le)) (sub_nonneg.mpr (hB zero_le)))
74
+ (massDifference_mesh_variation A B hA hB T)
75
+ (massTimeMesh_small_increments T _ hcont)
76
+
77
+ end SLEExactGauge
78
+
79
+ end
80
+
81
+ end OAI
lean/OAI/Probability/SLE/Mass/MassUniquenessPartitions.lean ADDED
@@ -0,0 +1,87 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Mass.MassUniquenessSeparation
2
+ import Mathlib.Analysis.SpecificLimits.Basic
3
+
4
+ namespace OAI
5
+
6
+ /-! Finite-variation estimates for the smooth separator on time partitions. -/
7
+
8
+ noncomputable section
9
+ open Set Filter
10
+ open scoped Topology NNReal
11
+
12
+ namespace SLEExactGauge
13
+
14
+ def massPartitionRemainder (x : ℕ → ℝ) (N : ℕ) : ℝ :=
15
+ massSeparationTest (x N)-massSeparationTest (x 0) -
16
+ ∑ i ∈ Finset.range N, massSeparationSlope (x i)*(x (i+1)-x i)
17
+
18
+ lemma massPartitionRemainder_eq_sum (x : ℕ → ℝ) (N : ℕ) :
19
+ massPartitionRemainder x N = ∑ i ∈ Finset.range N,
20
+ (massSeparationTest (x (i+1))-massSeparationTest (x i)-
21
+ massSeparationSlope (x i)*(x (i+1)-x i)) := by
22
+ rw [Finset.sum_sub_distrib,
23
+ Finset.sum_range_sub (fun i => massSeparationTest (x i)) N]
24
+ rfl
25
+
26
+ lemma massPartitionRemainder_linear (x : ℕ → ℝ) (N : ℕ) :
27
+ |massPartitionRemainder x N| ≤ 4*∑ i ∈ Finset.range N, |x (i+1)-x i| := by
28
+ rw [massPartitionRemainder_eq_sum,Finset.mul_sum]
29
+ exact (Finset.abs_sum_le_sum_abs _ _).trans
30
+ (Finset.sum_le_sum (fun i _ => massSeparationTest_remainder_linear (x i) (x (i+1))))
31
+
32
+ lemma massPartitionRemainder_small (x : ℕ → ℝ) (N : ℕ) {ε : ℝ}
33
+ (hx : ∀ i < N, |x (i+1)-x i| ≤ ε) :
34
+ |massPartitionRemainder x N| ≤ (8*ε)*∑ i ∈ Finset.range N, |x (i+1)-x i| := by
35
+ rw [massPartitionRemainder_eq_sum,Finset.mul_sum]
36
+ apply (Finset.abs_sum_le_sum_abs _ _).trans
37
+ apply Finset.sum_le_sum
38
+ intro i hi
39
+ exact (massSeparationTest_remainder_le (x i) (x (i+1))).trans (by
40
+ rw [pow_two,mul_assoc]
41
+ exact mul_le_mul_of_nonneg_left
42
+ (mul_le_mul_of_nonneg_right (hx i (Finset.mem_range.mp hi)) (abs_nonneg _)) (by norm_num))
43
+
44
+ lemma massDifference_partition_variation (A B : ℕ → ℝ)
45
+ (hA : Monotone A) (hB : Monotone B) (N : ℕ) :
46
+ (∑ i ∈ Finset.range N, |(A (i+1)-B (i+1))-(A i-B i)|) ≤
47
+ (A N-A 0)+(B N-B 0) := by
48
+ calc
49
+ _ ≤ ∑ i ∈ Finset.range N, ((A (i+1)-A i)+(B (i+1)-B i)) := by
50
+ apply Finset.sum_le_sum
51
+ intro i _
52
+ have hAi : 0 ≤ A (i+1)-A i := sub_nonneg.mpr (hA (Nat.le_succ i))
53
+ have hBi : 0 ≤ B (i+1)-B i := sub_nonneg.mpr (hB (Nat.le_succ i))
54
+ calc
55
+ _ = |(A (i+1)-A i)-(B (i+1)-B i)| := by congr 1; ring
56
+ _ ≤ |A (i+1)-A i|+|B (i+1)-B i| := abs_sub _ _
57
+ _ = _ := by rw [abs_of_nonneg hAi,abs_of_nonneg hBi]
58
+ _ = _ := by rw [Finset.sum_add_distrib,Finset.sum_range_sub,Finset.sum_range_sub]
59
+
60
+ lemma massPartitionRemainder_tendsto_zero
61
+ (x : ℕ → ℕ → ℝ) (N : ℕ → ℕ) (D : ℝ) (hD : 0 ≤ D)
62
+ (hvar : ∀ n, (∑ i ∈ Finset.range (N n), |x n (i+1)-x n i|) ≤ D)
63
+ (hsmall : ∀ ε : ℝ, 0 < ε → ∀ᶠ n in atTop, ∀ i < N n, |x n (i+1)-x n i| ≤ ε) :
64
+ Tendsto (fun n => massPartitionRemainder (x n) (N n)) atTop (𝓝 0) := by
65
+ apply Metric.tendsto_atTop.mpr
66
+ intro ε hε
67
+ let η := ε/(16*(D+1))
68
+ have hη : 0 < η := div_pos hε (by positivity)
69
+ obtain ⟨n₀,hn₀⟩ := eventually_atTop.mp (hsmall η hη)
70
+ refine ⟨n₀,fun n hn => ?_⟩
71
+ rw [Real.dist_eq,sub_zero]
72
+ calc
73
+ _ ≤ (8*η)*∑ i ∈ Finset.range (N n), |x n (i+1)-x n i| :=
74
+ massPartitionRemainder_small (x n) (N n) (hn₀ n hn)
75
+ _ ≤ (8*η)*D := mul_le_mul_of_nonneg_left (hvar n) (by positivity)
76
+ _ < ε := by
77
+ dsimp only [η]
78
+ have hpos : 0 < D+1 := by linarith
79
+ rw [show 8*(ε/(16*(D+1)))*D = (8*ε*D)/(16*(D+1)) by ring]
80
+ apply (div_lt_iff₀ (by positivity : 0 < 16*(D+1))).mpr
81
+ nlinarith
82
+
83
+ end SLEExactGauge
84
+
85
+ end
86
+
87
+ end OAI
lean/OAI/Probability/SLE/Mass/MassUniquenessSeparation.lean ADDED
@@ -0,0 +1,124 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import Mathlib.Analysis.Calculus.MeanValue
2
+ import Mathlib.Analysis.Calculus.Deriv.Pow
3
+ import Mathlib.Analysis.Calculus.Deriv.Inv
4
+ import Mathlib.Analysis.SpecialFunctions.Pow.Real
5
+
6
+ namespace OAI
7
+
8
+ /-! A bounded smooth test detecting a nonzero continuous finite-variation
9
+ martingale. Its bounded derivatives permit an integrable-variation argument. -/
10
+
11
+ noncomputable section
12
+ open Set
13
+ open scoped Topology
14
+
15
+ namespace SLEExactGauge
16
+
17
+ def massSeparationTest (x : ℝ) : ℝ := x^2 / (1+x^2)
18
+ def massSeparationSlope (x : ℝ) : ℝ := 2*x / (1+x^2)^2
19
+
20
+ theorem massSeparationTest_nonneg (x : ℝ) : 0 ≤ massSeparationTest x := by
21
+ unfold massSeparationTest
22
+ positivity
23
+
24
+ @[simp] theorem massSeparationTest_zero : massSeparationTest 0 = 0 := by
25
+ norm_num [massSeparationTest]
26
+
27
+ @[simp] theorem massSeparationTest_eq_zero (x : ℝ) : massSeparationTest x = 0 ↔ x = 0 := by
28
+ have hp : 0 < 1+x^2 := by positivity
29
+ simp only [massSeparationTest,div_eq_zero_iff,hp.ne',or_false,pow_eq_zero_iff (by decide : (2:ℕ) ≠ 0)]
30
+
31
+ theorem massSeparationTest_hasDerivAt (x : ℝ) :
32
+ HasDerivAt massSeparationTest (massSeparationSlope x) x := by
33
+ have hd := ((hasDerivAt_id x).pow 2).div
34
+ ((hasDerivAt_const x 1).add ((hasDerivAt_id x).pow 2)) (by positivity : 1+x^2 ≠ 0)
35
+ convert hd using 1
36
+ · rfl
37
+ · dsimp only [massSeparationSlope,id_eq,Pi.pow_apply,Pi.add_apply,Pi.div_apply]
38
+ field_simp
39
+ ring
40
+
41
+ theorem massSeparationSlope_hasDerivAt (x : ℝ) :
42
+ HasDerivAt massSeparationSlope ((2-6*x^2)/(1+x^2)^3) x := by
43
+ have hd := ((hasDerivAt_id x).const_mul 2).div
44
+ (((hasDerivAt_const x 1).add ((hasDerivAt_id x).pow 2)).pow 2)
45
+ (by positivity : (1+x^2)^2 ≠ 0)
46
+ convert hd using 1
47
+ · rfl
48
+ · dsimp only [id_eq,Pi.pow_apply,Pi.add_apply,Pi.div_apply]
49
+ field_simp
50
+ ring
51
+
52
+ theorem massSeparationSlope_abs_le (x : ℝ) : |massSeparationSlope x| ≤ 2 := by
53
+ have hy : 0 ≤ x^2 := sq_nonneg x
54
+ have hx : |x| ≤ 1+x^2 := by
55
+ nlinarith [sq_nonneg (|x|-1),sq_abs x]
56
+ have hp : 0 < 1+x^2 := by positivity
57
+ rw [massSeparationSlope,abs_div,abs_mul,abs_of_pos (sq_pos_of_pos hp)]
58
+ norm_num only [abs_of_pos (by norm_num : (0:ℝ)<2)]
59
+ apply (div_le_iff₀ (sq_pos_of_pos hp)).mpr
60
+ nlinarith [sq_nonneg (x^2)]
61
+
62
+ theorem massSeparationSlope_deriv_abs_le (x : ℝ) :
63
+ |(2-6*x^2)/(1+x^2)^3| ≤ 8 := by
64
+ have hp : 0 < 1+x^2 := by positivity
65
+ rw [abs_div,abs_of_pos (pow_pos hp 3)]
66
+ apply (div_le_iff₀ (pow_pos hp 3)).mpr
67
+ have hn : |2-6*x^2| ≤ 2+6*x^2 := by
68
+ have hh := abs_sub (2:ℝ) (6*x^2)
69
+ norm_num [abs_mul,abs_of_nonneg (sq_nonneg x)] at hh ⊢
70
+ exact hh
71
+ have hb : 2+6*x^2 ≤ 8*(1+x^2)^3 := by
72
+ nlinarith [sq_nonneg (x^2),pow_nonneg (sq_nonneg x) 3]
73
+ exact hn.trans hb
74
+
75
+ theorem massSeparationTest_lipschitz (x y : ℝ) :
76
+ |massSeparationTest y-massSeparationTest x| ≤ 2*|y-x| := by
77
+ have h := Convex.norm_image_sub_le_of_norm_deriv_le
78
+ (s := (univ:Set ℝ)) (f := massSeparationTest) (C := 2) (x := x) (y := y)
79
+ (fun z _ => (massSeparationTest_hasDerivAt z).differentiableAt)
80
+ (fun z _ => by simpa only [(massSeparationTest_hasDerivAt z).deriv,Real.norm_eq_abs]
81
+ using massSeparationSlope_abs_le z) convex_univ (mem_univ x) (mem_univ y)
82
+ simpa only [Real.norm_eq_abs] using h
83
+
84
+ theorem massSeparationSlope_lipschitz (x y : ℝ) :
85
+ |massSeparationSlope y-massSeparationSlope x| ≤ 8*|y-x| := by
86
+ have h := Convex.norm_image_sub_le_of_norm_deriv_le
87
+ (s := (univ:Set ℝ)) (f := massSeparationSlope) (C := 8) (x := x) (y := y)
88
+ (fun z _ => (massSeparationSlope_hasDerivAt z).differentiableAt)
89
+ (fun z _ => by simpa only [(massSeparationSlope_hasDerivAt z).deriv,Real.norm_eq_abs]
90
+ using massSeparationSlope_deriv_abs_le z) convex_univ (mem_univ x) (mem_univ y)
91
+ simpa only [Real.norm_eq_abs] using h
92
+
93
+ theorem massSeparationTest_remainder_le (x y : ℝ) :
94
+ |massSeparationTest y-massSeparationTest x-massSeparationSlope x*(y-x)| ≤ 8*|y-x|^2 := by
95
+ let f (z : ℝ) := massSeparationTest z-massSeparationTest x-massSeparationSlope x*(z-x)
96
+ have hd (z : ℝ) : HasDerivAt f (massSeparationSlope z-massSeparationSlope x) z := by
97
+ convert ((massSeparationTest_hasDerivAt z).sub_const
98
+ (massSeparationTest x)).sub (((hasDerivAt_id z).sub_const x).const_mul (massSeparationSlope x)) using 1
99
+ · rfl
100
+ · ring
101
+ have h := Convex.norm_image_sub_le_of_norm_deriv_le
102
+ (s := Metric.closedBall x |y-x|) (f := f) (C := 8*|y-x|) (x := x) (y := y)
103
+ (fun z _ => (hd z).differentiableAt)
104
+ (fun z hz => by
105
+ rw [(hd z).deriv,Real.norm_eq_abs]
106
+ exact (massSeparationSlope_lipschitz x z).trans
107
+ (mul_le_mul_of_nonneg_left (by simpa only [Metric.mem_closedBall,Real.dist_eq] using hz) (by norm_num)))
108
+ (convex_closedBall x _) (Metric.mem_closedBall_self (abs_nonneg _))
109
+ (by simp only [Metric.mem_closedBall,Real.dist_eq,le_refl])
110
+ simpa only [f,sub_self,mul_zero,sub_zero,Real.norm_eq_abs,pow_two,mul_assoc] using h
111
+
112
+ theorem massSeparationTest_remainder_linear (x y : ℝ) :
113
+ |massSeparationTest y-massSeparationTest x-massSeparationSlope x*(y-x)| ≤ 4*|y-x| := by
114
+ calc
115
+ _ ≤ |massSeparationTest y-massSeparationTest x|+|massSeparationSlope x*(y-x)| := abs_sub _ _
116
+ _ ≤ 2*|y-x|+2*|y-x| := add_le_add (massSeparationTest_lipschitz x y)
117
+ (by rw [abs_mul]; exact mul_le_mul_of_nonneg_right (massSeparationSlope_abs_le x) (abs_nonneg _))
118
+ _ = _ := by ring
119
+
120
+ end SLEExactGauge
121
+
122
+ end
123
+
124
+ end OAI
lean/OAI/Probability/SLE/Mass/MomentLevels.lean ADDED
@@ -0,0 +1,77 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.MomentGauge
2
+
3
+ namespace OAI
4
+
5
+ /-!
6
+ The prescribed retained level in the first paper's moment-batch construction.
7
+ Its definition counts bad positive integer levels. Monotonicity makes those
8
+ levels an initial segment, so one plus their cardinal is a good level.
9
+ The moment convergence hypotheses here are explicit internal proof inputs.
10
+ -/
11
+
12
+ noncomputable section
13
+ open Set Filter
14
+ open scoped Topology
15
+
16
+ namespace SLEExactGauge.Target
17
+
18
+ theorem batchLevel_ge_one (κ : ℝ) (W : WienerLaw) (n : ℕ) :
19
+ 1 ≤ batchLevel κ W n := by
20
+ unfold batchLevel
21
+ omega
22
+
23
+ theorem finite_bad_moment_levels (κ : ℝ) (W : WienerLaw) (n : ℕ)
24
+ (hm : 0 < moment κ W n)
25
+ (hlim : Tendsto (fun j : ℕ => finiteMoment κ W n j) atTop (𝓝 (moment κ W n))) :
26
+ {j : ℕ | 1 ≤ j ∧ finiteMoment κ W n j ≤ 3 * moment κ W n / 4}.Finite := by
27
+ have hlt : 3 * moment κ W n / 4 < moment κ W n := by linarith
28
+ have hevent : ∀ᶠ j : ℕ in atTop, 3 * moment κ W n / 4 < finiteMoment κ W n j :=
29
+ (tendsto_order.mp hlim).1 _ hlt
30
+ obtain ⟨N, hN⟩ := eventually_atTop.mp hevent
31
+ apply (finite_Iio N).subset
32
+ intro j hj
33
+ show j < N
34
+ by_contra hjN
35
+ exact (not_le_of_gt (hN j (le_of_not_gt hjN))) hj.2
36
+
37
+ /-- The actual `Target.batchLevel`, not a separately chosen large level,
38
+ retains more than three quarters of the limiting moment. -/
39
+ theorem finiteMoment_batchLevel_gt (κ : ℝ) (W : WienerLaw) (n : ℕ)
40
+ (hmono : Monotone (fun j : ℕ => finiteMoment κ W n j))
41
+ (hm : 0 < moment κ W n)
42
+ (hlim : Tendsto (fun j : ℕ => finiteMoment κ W n j) atTop (𝓝 (moment κ W n))) :
43
+ 3 * moment κ W n / 4 < finiteMoment κ W n (batchLevel κ W n) := by
44
+ classical
45
+ let B := {j : ℕ // 1 ≤ j ∧ finiteMoment κ W n j ≤ 3 * moment κ W n / 4}
46
+ let : Finite B := (finite_bad_moment_levels κ W n hm hlim).to_subtype
47
+ by_contra hbad
48
+ have hbad' : finiteMoment κ W n (batchLevel κ W n) ≤ 3 * moment κ W n / 4 :=
49
+ le_of_not_gt hbad
50
+ let f : Fin (batchLevel κ W n) → B := fun j =>
51
+ ⟨(j : ℕ) + 1, by
52
+ refine ⟨by omega, ?_⟩
53
+ exact (hmono (Nat.succ_le_of_lt j.isLt)).trans hbad'⟩
54
+ have hinj : Function.Injective f := by
55
+ intro i j hij
56
+ apply Fin.ext
57
+ have hval := congrArg Subtype.val hij
58
+ dsimp only [f] at hval
59
+ omega
60
+ have hcard := Nat.card_le_card_of_injective f hinj
61
+ rw [Nat.card_fin] at hcard
62
+ change 1 + Nat.card B ≤ Nat.card B at hcard
63
+ omega
64
+
65
+ theorem batchLevel_retains_moment (κ : ℝ) (W : WienerLaw) (n : ℕ)
66
+ (hmono : Monotone (fun j : ℕ => finiteMoment κ W n j))
67
+ (hm : 0 < moment κ W n)
68
+ (hlim : Tendsto (fun j : ℕ => finiteMoment κ W n j) atTop (𝓝 (moment κ W n))) :
69
+ 1 ≤ batchLevel κ W n ∧
70
+ 3 * moment κ W n / 4 < finiteMoment κ W n (batchLevel κ W n) :=
71
+ ⟨batchLevel_ge_one κ W n, finiteMoment_batchLevel_gt κ W n hmono hm hlim⟩
72
+
73
+ end SLEExactGauge.Target
74
+
75
+ end
76
+
77
+ end OAI
lean/OAI/Probability/SLE/Mass/MonotoneMassExhaustion.lean ADDED
@@ -0,0 +1,33 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import Mathlib.MeasureTheory.Integral.Lebesgue.DominatedConvergence
2
+ import Mathlib.Topology.Order.MonotoneConvergence
3
+
4
+ namespace OAI
5
+
6
+ /-! Nonnegative decreasing remaining masses vanish almost surely when
7
+ their expectations tend to zero. -/
8
+
9
+ noncomputable section
10
+ open Set Filter MeasureTheory
11
+ open scoped ENNReal Topology
12
+
13
+ namespace SLEExactGauge
14
+
15
+ theorem ae_tendsto_zero_of_antitone_lintegral
16
+ {Ω : Type*} [MeasurableSpace Ω] (P : Measure Ω) (f : ℕ → Ω → ℝ≥0∞)
17
+ (hf : ∀ n, Measurable (f n)) (hanti : ∀ᵐ ω ∂P, Antitone (fun n => f n ω))
18
+ (hmean : Tendsto (fun n => ∫⁻ ω, f n ω ∂P) atTop (𝓝 0)) :
19
+ ∀ᵐ ω ∂P, Tendsto (fun n => f n ω) atTop (𝓝 0) := by
20
+ have hi : (∫⁻ ω, liminf (fun n => f n ω) atTop ∂P) = 0 := by
21
+ apply le_zero_iff.mp
22
+ exact (lintegral_liminf_le hf).trans_eq hmean.liminf_eq
23
+ have hz := (lintegral_eq_zero_iff (Measurable.liminf hf)).mp hi
24
+ filter_upwards [hanti,hz] with ω ha hz
25
+ have ht := tendsto_atTop_iInf ha
26
+ have he : (⨅ n, f n ω) = 0 := ht.liminf_eq.symm.trans hz
27
+ rwa [he] at ht
28
+
29
+ end SLEExactGauge
30
+
31
+ end
32
+
33
+ end OAI
lean/OAI/Probability/SLE/Mass/NonnegativeL2Passage.lean ADDED
@@ -0,0 +1,56 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.ExponentialMartingales
2
+
3
+ namespace OAI
4
+
5
+ /-! Uniform second moments of terminal tests also control every smaller
6
+ nonnegative test, including tests evaluated at random times. -/
7
+
8
+ noncomputable section
9
+ open Set Filter MeasureTheory
10
+ open scoped ENNReal Topology
11
+
12
+ namespace SLEExactGauge
13
+
14
+ lemma memLp_two_of_nonnegative_square_bound
15
+ {Ω : Type*} [MeasurableSpace Ω] (P : Measure Ω) (X : Ω → ℝ)
16
+ (hm : Measurable X) (hX : ∀ ω, 0 ≤ X ω)
17
+ (M : ℝ≥0∞) (hM : M < ∞)
18
+ (hb : (∫⁻ ω, ENNReal.ofReal (X ω)^2 ∂P) ≤ M) :
19
+ MemLp X 2 P ∧ (∫ ω, X ω^2 ∂P) ≤ M.toReal := by
20
+ have hi : Integrable (fun ω => X ω^2) P := by
21
+ refine ⟨(hm.pow_const 2).aestronglyMeasurable,?_⟩
22
+ apply (hasFiniteIntegral_iff_ofReal (ae_of_all _ (fun ω => sq_nonneg (X ω)))).mpr
23
+ simpa only [ENNReal.ofReal_pow (hX _)] using hb.trans_lt hM
24
+ have hmem := (memLp_two_iff_integrable_sq hm.aestronglyMeasurable).mpr hi
25
+ refine ⟨hmem,?_⟩
26
+ have he : ENNReal.ofReal (∫ ω, X ω^2 ∂P) ≤ M := by
27
+ rw [ofReal_integral_eq_lintegral_ofReal hi (ae_of_all _ (fun ω => sq_nonneg (X ω)))]
28
+ simpa only [ENNReal.ofReal_pow (hX _)] using hb
29
+ have ht := ENNReal.toReal_mono hM.ne he
30
+ rwa [ENNReal.toReal_ofReal (integral_nonneg (fun ω => sq_nonneg (X ω)))] at ht
31
+
32
+ theorem integral_tendsto_of_nonnegative_L2_domination
33
+ {Ω : Type*} [MeasurableSpace Ω] (P : Measure Ω) [IsFiniteMeasure P]
34
+ (X Z : ℕ → Ω → ℝ) (Y : Ω → ℝ)
35
+ (hXm : ∀ n, Measurable (X n)) (hX0 : ∀ n ω, 0 ≤ X n ω)
36
+ (hXZ : ∀ n ω, X n ω ≤ Z n ω) (hZ : ∀ n, MemLp (Z n) 2 P)
37
+ (A : ℝ) (hA : ∀ n, (∫ ω, Z n ω^2 ∂P) ≤ A)
38
+ (hlim : ∀ᵐ ω ∂P, Tendsto (fun n => X n ω) atTop (𝓝 (Y ω))) :
39
+ Integrable Y P ∧
40
+ Tendsto (fun n => ∫ ω, X n ω ∂P) atTop (𝓝 (∫ ω, Y ω ∂P)) := by
41
+ have hX (n : ℕ) : MemLp (X n) 2 P :=
42
+ (hZ n).mono' (hXm n).aestronglyMeasurable
43
+ (ae_of_all _ (fun ω => by simpa only [Real.norm_of_nonneg (hX0 n ω)] using hXZ n ω))
44
+ have hsq (n : ℕ) : (∫ ω, X n ω^2 ∂P) ≤ A := by
45
+ apply (integral_mono (hX n).integrable_sq (hZ n).integrable_sq ?_).trans (hA n)
46
+ intro ω
47
+ exact pow_le_pow_left₀ (hX0 n ω) (hXZ n ω) 2
48
+ obtain ⟨hY,hL1⟩ := finite_L1_tendsto_of_square_bound hX A hsq hlim
49
+ exact ⟨hY,tendsto_integral_of_L1' Y
50
+ (Eventually.of_forall (fun n => (hX n).integrable (by norm_num))) hL1⟩
51
+
52
+ end SLEExactGauge
53
+
54
+ end
55
+
56
+ end OAI
lean/OAI/Probability/SLE/Mass/NormalizedDiskCompensator.lean ADDED
@@ -0,0 +1,92 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Geometry.CanonicalNormalizedPotential
2
+ import OAI.Probability.SLE.Mass.CanonicalMassCompensator
3
+
4
+ namespace OAI
5
+
6
+ /-! Recovery of the actual canonical disk mass on the exact target
7
+ Brownian-time dyadic grid. -/
8
+
9
+ noncomputable section
10
+ open Set Filter _root_.MeasureTheory _root_.OAI.MeasureTheory ProbabilityTheory
11
+ open scoped Topology NNReal ENNReal
12
+
13
+ namespace SLEExactGauge.Multipoint.CanonicalMass
14
+
15
+ variable {Ω : Type*} [mΩ : MeasurableSpace Ω] {P : Measure Ω}
16
+ {κ : ℝ}
17
+ {B : ℝ≥0 → Ω → ℝ} {hBm : Measurable (Function.uncurry B)}
18
+ {γ : Ω → ℝ≥0 → ℂ} {G : Ω → ℝ≥0 → ℂ → ℂ}
19
+ (C : CanonicalMass P κ B hBm γ G)
20
+
21
+ def normalizedDiskScalar (θ : ℝ) (hθ : θ ∈ Ioo (0:ℝ) Real.pi)
22
+ (t : ℝ≥0) (ω : Ω) : ℝ := C.diskScalar θ hθ (t/κ.toNNReal) ω
23
+
24
+ lemma normalizedDiskScalar_measurable (θ : ℝ) (hθ : θ ∈ Ioo (0:ℝ) Real.pi)
25
+ (t : ℝ≥0) : Measurable (C.normalizedDiskScalar θ hθ t) :=
26
+ (compactWeightedMass_measurable _ _
27
+ (Target.diskSourceHalfPlane_compact hθ).measurableSet).comp
28
+ C.progressive.adapted.measurable
29
+
30
+ lemma normalizedDiskScalar_integrable (θ : ℝ) (hθ : θ ∈ Ioo (0:ℝ) Real.pi)
31
+ (t : ℝ≥0) : Integrable (C.normalizedDiskScalar θ hθ t) P := by
32
+ exact (compactWeightedMass_kernel_integrable P κ (C.process (t/κ.toNNReal))
33
+ C.progressive.adapted.measurable
34
+ (by simpa only [Measure.restrict_univ] using
35
+ C.uniqueness_process_mean_le (t/κ.toNNReal) univ)
36
+ _ _ (Target.diskSourceHalfPlane_compact hθ)).1
37
+
38
+ lemma normalizedDiskScalar_stronglyAdapted (hκ : 0<κ)
39
+ (hc : ∀ ω, Continuous (fun t => B t ω)) (h0 : ∀ ω, B 0 ω=0)
40
+ (θ : ℝ) (hθ : θ ∈ Ioo (0:ℝ) Real.pi) :
41
+ StronglyAdapted (Target.normalizedFiltration κ B
42
+ (fun r => (hBm.comp (measurable_const.prodMk measurable_id) : Measurable (B r))) hc h0)
43
+ (C.normalizedDiskScalar θ hθ) := by
44
+ intro t
45
+ erw [Target.normalizedFiltration_at κ hκ]
46
+ exact ((compactWeightedMass_measurable _ _
47
+ (Target.diskSourceHalfPlane_compact hθ).measurableSet).comp
48
+ (C.progressive.adapted (t/κ.toNNReal))).stronglyMeasurable
49
+
50
+ theorem normalizedDiskScalar_paths (hκ : 0<κ)
51
+ (θ : ℝ) (hθ : θ ∈ Ioo (0:ℝ) Real.pi) :
52
+ ∀ᵐ ω ∂P, Monotone (fun t => C.normalizedDiskScalar θ hθ t ω) ∧
53
+ C.normalizedDiskScalar θ hθ 0 ω=0 ∧
54
+ Continuous (fun t => C.normalizedDiskScalar θ hθ t ω) ∧
55
+ Tendsto (fun t => C.normalizedDiskScalar θ hθ t ω) atTop
56
+ (𝓝 (C.diskTerminalScalar θ hθ ω)) ∧
57
+ ∀ t, C.normalizedDiskScalar θ hθ t ω ≤ C.diskTerminalScalar θ hθ ω := by
58
+ filter_upwards [C.compactWeightedMass_paths (Target.diskMassWeight κ θ hθ)
59
+ (Target.diskSourceHalfPlane θ) (Target.diskSourceHalfPlane_compact hθ)] with ω hω
60
+ refine ⟨?_,?_,hω.2.2.1.comp (continuous_id.div_const _),?_,fun t => hω.2.2.2.2 _⟩
61
+ · intro s t hst
62
+ exact hω.1 (div_le_div_of_nonneg_right hst zero_le)
63
+ · simpa only [normalizedDiskScalar,diskScalar,zero_div] using hω.2.1
64
+ · exact hω.2.2.2.1.comp
65
+ ((tendsto_div_const_atTop_of_pos (Real.toNNReal_pos.mpr hκ)).mpr tendsto_id)
66
+
67
+ theorem normalized_disk_compensator_recovery [IsProbabilityMeasure P]
68
+ (hκ : 0<κ) (hc : ∀ ω, Continuous (fun t => B t ω)) (h0 : ∀ ω, B 0 ω=0)
69
+ (θ : ℝ) (hθ : θ ∈ Ioo (0:ℝ) Real.pi) (T : Ω → ℝ≥0∞) (hT : Measurable T) :
70
+ TendstoInMeasure P
71
+ (fun n ω => meshMassCompensator P
72
+ (compensatorMeshFiltration (Target.normalizedFiltration κ B
73
+ (fun r => (hBm.comp (measurable_const.prodMk measurable_id) : Measurable (B r))) hc h0))
74
+ (C.normalizedDiskScalar θ hθ) n (compensatorStopIndex n (T ω)) ω) atTop
75
+ (fun ω => massAtExtendedTime (fun t => C.normalizedDiskScalar θ hθ t ω)
76
+ (C.diskTerminalScalar θ hθ ω) (T ω)) := by
77
+ apply meshMassCompensator_stopped_tendstoInMeasure P _ _ _ _ _
78
+ (C.compactWeightedMass_terminal_memLp _ _ (Target.diskSourceHalfPlane_compact hθ))
79
+ (C.normalizedDiskScalar_paths hκ θ hθ) T hT
80
+ · intro t
81
+ exact C.normalizedDiskScalar_measurable θ hθ t
82
+ · intro n i
83
+ change StronglyMeasurable[Target.normalizedFiltration κ B
84
+ (fun r => (hBm.comp (measurable_const.prodMk measurable_id) : Measurable (B r)))
85
+ hc h0 (compensatorMeshTime n i)] _
86
+ exact C.normalizedDiskScalar_stronglyAdapted hκ hc h0 θ hθ _
87
+
88
+ end SLEExactGauge.Multipoint.CanonicalMass
89
+
90
+ end
91
+
92
+ end OAI
lean/OAI/Probability/SLE/Mass/OriginalShiftedMass.lean ADDED
@@ -0,0 +1,58 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Mass.CanonicalMassRemaining
2
+ import OAI.Probability.SLE.Stochastic.ProgressiveStoppedTime
3
+
4
+ namespace OAI
5
+
6
+ /-! The original canonical mass evaluated after a finite stopping time.
7
+ Its remaining Green kernel is stated in the full shifted filtration. -/
8
+
9
+ noncomputable section
10
+ open Set Filter _root_.MeasureTheory _root_.OAI.MeasureTheory Classical
11
+ open scoped NNReal ENNReal Topology
12
+
13
+ namespace SLEExactGauge.Multipoint
14
+
15
+ lemma extendedCanonicalMass_finite_time
16
+ {Ω : Type*} (N : ℝ≥0 → Ω → Measure upperHalfPlane)
17
+ (ν : Ω → Measure upperHalfPlane) (τ : Ω → ℝ≥0) (ω : Ω) :
18
+ extendedCanonicalMass N ν (τ ω:ℝ≥0∞) ω=N (τ ω) ω := by
19
+ simp only [extendedCanonicalMass,ENNReal.coe_lt_top,ite_true,ENNReal.toNNReal_coe]
20
+
21
+ variable {Ω : Type*} [MeasurableSpace Ω] {P : Measure Ω} {κ : ℝ}
22
+ {B : ℝ≥0 → Ω → ℝ} {hBm : Measurable (Function.uncurry B)}
23
+ {γ : Ω → ℝ≥0 → ℂ} {G : Ω → ℝ≥0 → ℂ → ℂ}
24
+ (C : CanonicalMass P κ B hBm γ G) (τ : Ω → ℝ≥0)
25
+ (hτ : IsStoppingTime (Filtration.natural B (fun s =>
26
+ (hBm.comp (measurable_const.prodMk measurable_id) : Measurable (B s)).stronglyMeasurable))
27
+ (fun ω => (τ ω:WithTop ℝ≥0)))
28
+
29
+ include C τ hτ in
30
+ lemma CanonicalMass.original_shifted_adapted :
31
+ Adapted (shiftedStoppingFiltration hτ) (fun t ω => C.process (τ ω+t) ω) :=
32
+ _root_.OAI.MeasureTheory.IsProgressive.shifted_adapted C.progressive τ hτ
33
+
34
+ include C τ hτ in
35
+ lemma CanonicalMass.original_shifted_green_kernel
36
+ (t : ℝ≥0) (E : Set Ω) (hE : MeasurableSet[shiftedStoppingFiltration hτ t] E) :
37
+ (P.restrict E).bind C.rational.terminal =
38
+ (P.restrict E).bind (fun ω => C.process (τ ω+t) ω)+
39
+ (P.restrict E).bind (fun ω => halfPlaneGreenMeasure κ B γ G (τ ω+t) ω) := by
40
+ have h := C.kernel (fun ω => ((τ ω+t:ℝ≥0):WithTop ℝ≥0))
41
+ (stopping_time_add_nnreal hτ t) E hE
42
+ change (P.restrict E).bind C.rational.terminal =
43
+ (P.restrict E).bind (fun ω => C.process (τ ω+t) ω)+
44
+ (P.restrict E).bind (fun ω => halfPlaneGreenMeasure κ B γ G (τ ω+t) ω) at h
45
+ exact h
46
+
47
+ include C τ hτ in
48
+ lemma CanonicalMass.original_shifted_mean_le (t : ℝ≥0) (E : Set Ω) :
49
+ (P.restrict E).bind (fun ω => C.process (τ ω+t) ω) ≤ initialGreenMeasure κ := by
50
+ have h := C.atTime_mean_le (fun ω => ((τ ω+t:ℝ≥0):ℝ≥0∞))
51
+ (stopping_time_add_nnreal hτ t).measurable' E
52
+ exact h
53
+
54
+ end SLEExactGauge.Multipoint
55
+
56
+ end
57
+
58
+ end OAI
lean/OAI/Probability/SLE/Mass/PastThresholdMass.lean ADDED
@@ -0,0 +1,63 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Gauge.StrictPastCountable
2
+ import OAI.Probability.SLE.Geometry.WeightedCompactTerminal
3
+
4
+ namespace OAI
5
+
6
+ /-! Continuous mass crosses an intermediate level at a dense test time.
7
+ Consequently a cell with twice the threshold has at least half its mass
8
+ strictly after a successful past test. -/
9
+
10
+ noncomputable section
11
+ open Set Filter _root_.MeasureTheory _root_.OAI.MeasureTheory ProbabilityTheory
12
+ open scoped Topology NNReal ENNReal
13
+ attribute [local instance] Classical.propDecidable
14
+
15
+ namespace SLEExactGauge.Multipoint
16
+
17
+ lemma dense_time_between_mass_levels (q : ℕ → ℝ≥0) (hq : DenseRange q)
18
+ (f : ℝ≥0 → ℝ) (hf : Continuous f) (h0 : f 0=0)
19
+ (M H L : ℝ) (hH : 0<H) (hHL : H<L) (hLM : L<M)
20
+ (hlim : Tendsto f atTop (𝓝 M)) : ∃ n, H<f (q n) ∧ f (q n)<L := by
21
+ obtain ⟨T,hT⟩ := (hlim.eventually (lt_mem_nhds hLM)).exists
22
+ obtain ⟨t,_,ht⟩ := intermediate_value_Icc (show (0:ℝ≥0)≤T from bot_le)
23
+ hf.continuousOn (show (H+L)/2∈Icc (f 0) (f T) by rw [h0]; constructor <;> linarith)
24
+ have hopen : IsOpen (f ⁻¹' Ioo H L) := isOpen_Ioo.preimage hf
25
+ have hne : (f ⁻¹' Ioo H L).Nonempty := ⟨t,by change H<f t ∧ f t<L; rw [ht]; constructor <;> linarith⟩
26
+ exact hq.exists_mem_open hopen hne
27
+
28
+ lemma past_threshold_detects_half
29
+ {X : Type*} [MeasurableSpace X] (μ : Measure X) (K : Set X)
30
+ (hfin : μ K≠∞)
31
+ (A : ℝ≥0 → Set X) (hA : ∀ t, MeasurableSet (A t))
32
+ (q : ℕ → ℝ≥0) (hq : DenseRange q) (f : ℝ≥0 → ℝ)
33
+ (hf : Continuous f) (h0 : f 0=0)
34
+ (hlim : Tendsto f atTop (𝓝 (μ K).toReal))
35
+ (hpast : ∀ n, μ (K ∩ A (q n))=ENNReal.ofReal (f (q n)))
36
+ (H : ℝ) (hH : 0<H) (hlarge : ENNReal.ofReal (2*H)<μ K) :
37
+ μ K≤2*μ (K ∩ ⋃ n, if H<f (q n) then (A (q n))ᶜ else ∅) := by
38
+ have hreal : 2*H<(μ K).toReal := by
39
+ have he := (ENNReal.toReal_lt_toReal ENNReal.ofReal_ne_top hfin).2 hlarge
40
+ simpa only [ENNReal.toReal_ofReal (by positivity : 0≤2*H)] using he
41
+ obtain ⟨n,hnH,hnM⟩ := dense_time_between_mass_levels q hq f hf h0 (μ K).toReal H
42
+ ((μ K).toReal/2) hH (by linarith) (by linarith) hlim
43
+ have hsub : K \ A (q n) ⊆ K ∩ ⋃ n, if H<f (q n) then (A (q n))ᶜ else ∅ := by
44
+ intro x hx
45
+ exact ⟨hx.1,mem_iUnion.mpr ⟨n,by rw [ite_eq_left hnH]; exact hx.2⟩⟩
46
+ have hfuture : μ K≤2*μ (K \ A (q n)) := by
47
+ have he := measure_inter_add_sdiff (μ:=μ) K (hA (q n))
48
+ rw [hpast n] at he
49
+ have hd : μ (K \ A (q n))≠∞ := ne_top_of_le_ne_top hfin (measure_mono sdiff_subset)
50
+ have hsum := congrArg ENNReal.toReal he
51
+ rw [ENNReal.toReal_add ENNReal.ofReal_ne_top hd,
52
+ ENNReal.toReal_ofReal (hH.trans hnH).le] at hsum
53
+ apply (ENNReal.toReal_le_toReal hfin (ENNReal.mul_ne_top (by norm_num) hd)).mp
54
+ rw [ENNReal.toReal_mul]
55
+ norm_num only [ENNReal.toReal_ofNat]
56
+ linarith
57
+ exact hfuture.trans (mul_le_mul' (show (2:ℝ≥0∞)≤2 from le_rfl) (measure_mono hsub))
58
+
59
+ end SLEExactGauge.Multipoint
60
+
61
+ end
62
+
63
+ end OAI
lean/OAI/Probability/SLE/Mass/PhysicalDiskMass.lean ADDED
@@ -0,0 +1,94 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Mass.DiskChartMass
2
+ import OAI.Probability.SLE.Geometry.PhysicalCellDisk
3
+
4
+ namespace OAI
5
+
6
+ /-! The disk scalar controls the actual centered and rescaled inverse
7
+ Loewner pushforward. The marked angle is retained exactly. -/
8
+
9
+ noncomputable section
10
+ open Set Filter _root_.MeasureTheory _root_.OAI.MeasureTheory Metric
11
+ open scoped Topology NNReal ENNReal
12
+
13
+ namespace SLEExactGauge
14
+ open Multipoint
15
+
16
+ lemma diskChartMass_eq_of_coordinates
17
+ (κ θ : ℝ) (f H : ℂ → ℂ)
18
+ (he : ∀ z ∈ upperHalfPlane, f (Target.diskMap θ z)=H z)
19
+ (μ : Measure upperHalfPlane) :
20
+ diskChartMass κ θ f μ = weightedImageMass (fun z : upperHalfPlane => H z)
21
+ (fun z : upperHalfPlane => ENNReal.ofReal (‖deriv H z‖^dimension κ)) μ := by
22
+ have hmap : (fun z : upperHalfPlane => f (Target.diskMap θ z))=
23
+ (fun z : upperHalfPlane => H z) := funext (fun z => he z z.property)
24
+ have hder (z : upperHalfPlane) : deriv (f ∘ Target.diskMap θ) z=deriv H z := by
25
+ apply Filter.EventuallyEq.deriv_eq
26
+ filter_upwards [isOpen_upperHalfPlane.mem_nhds z.property] with w hw
27
+ exact he w hw
28
+ unfold diskChartMass
29
+ rw [hmap]
30
+ congr 1
31
+ funext z
32
+ rw [hder]
33
+
34
+ lemma diskToHalfPlane_real_affine (c a : ℝ) (z ξ : ℂ)
35
+ (hξ : ξ ∈ ball (0:ℂ) 1) :
36
+ diskToHalfPlane ((c:ℂ)+(a:ℂ)*z) ξ =
37
+ (c:ℂ)+(a:ℂ)*diskToHalfPlane z ξ := by
38
+ simp only [diskToHalfPlane,star_add,star_mul,Complex.star_def,Complex.conj_ofReal]
39
+ field_simp [disk_denominator_ne hξ]
40
+ ring
41
+
42
+ lemma physicalDiskChart_normalized
43
+ (F G : ℝ≥0 → ℂ → ℂ) (t : ℝ≥0) (z : ℂ) (c a θ : ℝ)
44
+ (he : G t z=(c:ℂ)+(a:ℂ)*Complex.exp (θ*Complex.I))
45
+ {ξ : ℂ} (hξ : ξ ∈ ball (0:ℂ) 1) :
46
+ physicalDiskChart id F G t z ξ =
47
+ F t ((c:ℂ)+(a:ℂ)*Target.diskMapInv θ ξ) := by
48
+ change F t (diskToHalfPlane (G t z) ξ)=_
49
+ rw [he,diskToHalfPlane_real_affine c a _ ξ hξ,← Target.diskMapInv_eq_diskToHalfPlane]
50
+
51
+ lemma physicalDiskChart_mass_eq
52
+ (κ θ : ℝ) (hθ : θ ∈ Ioo (0:ℝ) Real.pi)
53
+ (F G : ℝ≥0 → ℂ → ℂ) (t : ℝ≥0) (z : ℂ) (c a : ℝ)
54
+ (he : G t z=(c:ℂ)+(a:ℂ)*Complex.exp (θ*Complex.I))
55
+ (μ : Measure upperHalfPlane) :
56
+ diskChartMass κ θ (physicalDiskChart id F G t z) μ =
57
+ weightedImageMass (fun w : upperHalfPlane => F t ((c:ℂ)+(a:ℂ)*w))
58
+ (fun w : upperHalfPlane => ENNReal.ofReal
59
+ (‖deriv (fun v : ℂ => F t ((c:ℂ)+(a:ℂ)*v)) w‖^dimension κ)) μ := by
60
+ apply diskChartMass_eq_of_coordinates κ θ (physicalDiskChart id F G t z)
61
+ (fun v : ℂ => F t ((c:ℂ)+(a:ℂ)*v))
62
+ intro w hw
63
+ rw [physicalDiskChart_normalized F G t z c a θ he (Target.diskMap_maps hθ hw),
64
+ Target.diskMapInv_diskMap hθ hw]
65
+
66
+ lemma IsCapacityTwoWitness.physical_quarter_mass_bounds
67
+ {U : ℝ≥0 → ℝ} {γ : ℝ≥0 → ℂ} {G F : ℝ≥0 → ℂ → ℂ}
68
+ (hw : IsCapacityTwoWitness U γ G F) (hgrowth : PublishedDiskUnivalentGrowth)
69
+ (κ : ℝ) (hκ : 0 < κ) (θ : ℝ) (hθ : θ ∈ Ioo (0:ℝ) Real.pi)
70
+ (t : ℝ≥0) (z : ℂ) (hz : z ∈ survivingDomain γ t) (a : ℝ)
71
+ (he : G t z=(U t:ℂ)+(a:ℂ)*Complex.exp (θ*Complex.I))
72
+ (μ : Measure upperHalfPlane) [IsFiniteMeasureOnCompacts μ] :
73
+ let f := physicalDiskChart id F G t z
74
+ let ν := weightedImageMass (fun w : upperHalfPlane => F t ((U t:ℂ)+(a:ℂ)*w))
75
+ (fun w : upperHalfPlane => ENNReal.ofReal
76
+ (‖deriv (fun v : ℂ => F t ((U t:ℂ)+(a:ℂ)*v)) w‖^dimension κ)) μ
77
+ let L := ENNReal.ofReal (compactWeightedMass (Target.diskMassWeight κ θ hθ)
78
+ (Target.diskSourceHalfPlane θ) μ)
79
+ ENNReal.ofReal ((fullRadius G t z/16)^dimension κ)*L ≤ ν (f '' Target.diskK) ∧
80
+ ν (f '' Target.diskK) ≤ ENNReal.ofReal ((16*fullRadius G t z)^dimension κ)*L := by
81
+ obtain ⟨hd,hi,_,hder,_⟩ := hw.physical_disk_chart id differentiableOn_id
82
+ (fun _ _ _ _ h => h) t z hz
83
+ have hder' : ‖deriv (physicalDiskChart id F G t z) 0‖=fullRadius G t z := by
84
+ simpa [physicalConformalRadius] using hder
85
+ have hb := diskChartMass_quarter_bounds hgrowth κ hκ θ hθ
86
+ (physicalDiskChart id F G t z) hd hi μ
87
+ rw [hder',physicalDiskChart_mass_eq κ θ hθ F G t z (U t) a he μ] at hb
88
+ exact hb
89
+
90
+ end SLEExactGauge
91
+
92
+ end
93
+
94
+ end OAI
lean/OAI/Probability/SLE/Mass/PositiveMassContinuity.lean ADDED
@@ -0,0 +1,37 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Loewner.StoppedInversePaths
2
+
3
+ namespace OAI
4
+
5
+ /-! Positive compact tests determine continuity of every real compact test. -/
6
+ noncomputable section
7
+ open Set Filter _root_.MeasureTheory _root_.OAI.MeasureTheory
8
+ open scoped Topology NNReal ENNReal CompactlySupported
9
+
10
+ namespace SLEExactGauge
11
+
12
+ lemma PositiveMassPaths.continuous_real_tests
13
+ {N : ℝ≥0 → Measure upperHalfPlane} {ν : Measure upperHalfPlane}
14
+ (h : PositiveMassPaths N ν) (f : C_c(upperHalfPlane,ℝ)) :
15
+ Continuous (fun t => ∫ z, f z ∂N t) := by
16
+ let fp : C_c(upperHalfPlane,ℝ) := f ⊔ 0
17
+ let fm : C_c(upperHalfPlane,ℝ) := -f ⊔ 0
18
+ have hp : ∀ z, 0 ≤ fp z := fun z => le_max_right _ _
19
+ have hm : ∀ z, 0 ≤ fm z := fun z => le_max_right _ _
20
+ have he (t : ℝ≥0) : (∫ z, f z ∂N t) = (∫ z, fp z ∂N t)-(∫ z, fm z ∂N t) := by
21
+ let := (h.radon t).2
22
+ rw [← integral_sub fp.integrable fm.integrable]
23
+ apply integral_congr_ae
24
+ exact ae_of_all _ (fun z => by
25
+ change f z = max (f z) 0-max (-f z) 0
26
+ rcases le_total 0 (f z) with hz | hz
27
+ · rw [max_eq_left hz,max_eq_right (neg_nonpos.mpr hz)]; ring
28
+ · rw [max_eq_right hz,max_eq_left (neg_nonneg.mpr hz)]; ring)
29
+ have hcont : Continuous (fun t => (∫ z, fp z ∂N t)-(∫ z, fm z ∂N t)) :=
30
+ (h.continuous_tests fp hp).sub (h.continuous_tests fm hm)
31
+ exact hcont.congr (fun t => (he t).symm)
32
+
33
+ end SLEExactGauge
34
+
35
+ end
36
+
37
+ end OAI
lean/OAI/Probability/SLE/Mass/PositiveMassGerm.lean ADDED
@@ -0,0 +1,98 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Stochastic.BrownianGerm
2
+ import OAI.Probability.SLE.Mass.CanonicalMassConstruction
3
+
4
+ namespace OAI
5
+
6
+ /-! A uniform positive chance of early mass, together with the Brownian
7
+ germ law, gives mass before every positive time. The scaling estimate
8
+ needed to apply this lemma is kept explicit. -/
9
+
10
+ noncomputable section
11
+ open Set Filter _root_.MeasureTheory _root_.OAI.MeasureTheory ProbabilityTheory
12
+ open scoped NNReal ENNReal Topology
13
+
14
+ namespace SLEExactGauge
15
+
16
+ lemma earlyMassGerm_tail {Ω : Type*} (E : ℕ → Set Ω) (k : ℕ) :
17
+ (⋂ N : ℕ, ⋃ j ≥ N, E j) = (⋂ N : ℕ, ⋃ j ≥ max N k, E j) := by
18
+ ext ω
19
+ simp only [mem_iInter,mem_iUnion]
20
+ constructor
21
+ · intro h N
22
+ exact h (max N k)
23
+ · intro h N
24
+ obtain ⟨j,hj,hE⟩ := h N
25
+ exact ⟨j,(le_max_left N k).trans hj,hE⟩
26
+
27
+ /-- This is the zero-one step of the canonical mass positivity argument.
28
+ The lower bound will come from scaling a single nonzero compact mean. -/
29
+ theorem positive_mass_all_times_of_uniform_probability
30
+ {Ω : Type*} [mΩ : MeasurableSpace Ω] {P : Measure Ω} [IsProbabilityMeasure P]
31
+ {B : ℝ≥0 → Ω → ℝ} (hB : IsBrownianReal B P) (hm : ∀ t, Measurable (B t))
32
+ (hc : ∀ ω, Continuous (fun t => B t ω)) (h0 : ∀ ω, B 0 ω=0)
33
+ (Z : ℝ≥0 → Ω → ℝ≥0∞)
34
+ (hZ : Adapted (Filtration.natural B (fun t => (hm t).stronglyMeasurable)) Z)
35
+ (hmono : ∀ᵐ ω ∂P, Monotone (fun t => Z t ω))
36
+ (ε : ℕ → ℝ≥0) (hεanti : Antitone ε) (hε : Tendsto ε atTop (𝓝 0))
37
+ (p : ℝ≥0∞) (hp : 0<p) (hprob : ∀ n, p ≤ P {ω | 0<Z (ε n) ω}) :
38
+ ∀ᵐ ω ∂P, ∀ t : ℝ≥0, 0<t → 0<Z t ω := by
39
+ let E : ℕ → Set Ω := fun n => {ω | 0<Z (ε n) ω}
40
+ let A : ℕ → Set Ω := fun N => ⋃ j ≥ N, E j
41
+ let G : Set Ω := ⋂ N, A N
42
+ have hEp (j k : ℕ) (hkj : k≤j) :
43
+ MeasurableSet[Filtration.natural B (fun t => (hm t).stronglyMeasurable) (ε k)] (E j) := by
44
+ have hz : Measurable[Filtration.natural B (fun t => (hm t).stronglyMeasurable) (ε k)]
45
+ (Z (ε j)) := (hZ (ε j)).mono
46
+ ((Filtration.natural B (fun t => (hm t).stronglyMeasurable)).mono (hεanti hkj)) le_rfl
47
+ exact measurableSet_lt measurable_const hz
48
+ have hGp (k : ℕ) : MeasurableSet[Filtration.natural B (fun t => (hm t).stronglyMeasurable) (ε k)] G := by
49
+ change MeasurableSet[Filtration.natural B (fun t => (hm t).stronglyMeasurable) (ε k)]
50
+ (⋂ N : ℕ, ⋃ j ≥ N, E j)
51
+ rw [earlyMassGerm_tail E k]
52
+ apply MeasurableSet.iInter
53
+ intro N
54
+ apply MeasurableSet.iUnion
55
+ intro j
56
+ apply MeasurableSet.iUnion
57
+ intro hj
58
+ exact hEp j k ((le_max_right N k).trans hj)
59
+ have hEm (j : ℕ) : MeasurableSet (E j) :=
60
+ (Filtration.natural B (fun t => (hm t).stronglyMeasurable)).le _ _ (hEp j j le_rfl)
61
+ have hAm (N : ℕ) : MeasurableSet (A N) :=
62
+ MeasurableSet.iUnion (fun j => MeasurableSet.iUnion (fun _ => hEm j))
63
+ have hGm : MeasurableSet G := MeasurableSet.iInter hAm
64
+ have hAa : Antitone A := by
65
+ intro N M hNM ω hω
66
+ obtain ⟨j,hj⟩ := mem_iUnion.mp hω
67
+ obtain ⟨hjM,hωE⟩ := mem_iUnion.mp hj
68
+ exact mem_iUnion.mpr ⟨j,mem_iUnion.mpr ⟨hNM.trans hjM,hωE⟩⟩
69
+ have hpG : p≤P G := by
70
+ change p≤P (⋂ N, A N)
71
+ rw [hAa.measure_iInter (fun N => (hAm N).nullMeasurableSet) ⟨0,measure_ne_top P _⟩]
72
+ apply le_iInf
73
+ intro N
74
+ apply (hprob N).trans (measure_mono ?_)
75
+ intro ω hω
76
+ exact mem_iUnion.mpr ⟨N,mem_iUnion.mpr ⟨le_rfl,hω⟩⟩
77
+ have hGone : P G=1 := by
78
+ rcases brownian_germ_zero_one hB hm hc h0 ε hε G hGp with hG | hG
79
+ · exact ((ne_of_gt hp) (le_zero_iff.mp (hpG.trans hG.le))).elim
80
+ · exact hG
81
+ have hGa : ∀ᵐ ω ∂P, ω∈G := (mem_ae_iff_prob_eq_one hGm).mpr hGone
82
+ filter_upwards [hGa,hmono] with ω hω hωmono
83
+ intro t ht
84
+ obtain ⟨N,hN⟩ := (hε.eventually (eventually_lt_nhds ht)).exists
85
+ have hg : ∀ N : ℕ, ∃ j, N≤j ∧ ω∈E j := by
86
+ intro N
87
+ change ω∈⋂ N, ⋃ j ≥ N, E j at hω
88
+ obtain ⟨j,hj⟩ := mem_iUnion.mp (mem_iInter.mp hω N)
89
+ obtain ⟨hNj,hmem⟩ := mem_iUnion.mp hj
90
+ exact ⟨j,hNj,hmem⟩
91
+ obtain ⟨j,hj,hωj⟩ := hg N
92
+ exact lt_of_lt_of_le hωj (hωmono ((hεanti hj).trans hN.le))
93
+
94
+ end SLEExactGauge
95
+
96
+ end
97
+
98
+ end OAI
lean/OAI/Probability/SLE/Mass/PositiveRestartMass.lean ADDED
@@ -0,0 +1,167 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Mass.CanonicalMassRestart
2
+ import OAI.Probability.SLE.Geometry.RestartGreenKernel
3
+
4
+ namespace OAI
5
+
6
+ /-! Positive mass survives the actual inverse-Loewner transport and
7
+ passes from initial intervals to every finite Brownian restart. -/
8
+
9
+ noncomputable section
10
+ open Set Filter _root_.MeasureTheory _root_.OAI.MeasureTheory ProbabilityTheory
11
+ open scoped NNReal ENNReal Topology
12
+
13
+ namespace SLEExactGauge
14
+
15
+ lemma weightedImageMass_ne_zero {X : Type*} [MeasurableSpace X]
16
+ (J : upperHalfPlane → X) (hJ : Measurable J)
17
+ (w : upperHalfPlane → ℝ≥0∞) (hw : Measurable w) (hp : ∀ z, 0<w z)
18
+ (μ : Measure upperHalfPlane) (hμ : μ≠0) : weightedImageMass J w μ≠0 := by
19
+ apply Measure.measure_univ_pos.mp
20
+ rw [weightedImageMass_apply J hJ w μ univ MeasurableSet.univ]
21
+ simp only [preimage_univ,indicator_univ]
22
+ rw [lintegral_pos_iff_support hw]
23
+ have he : Function.support w=univ := by
24
+ ext z
25
+ simp only [Function.mem_support,mem_univ,iff_true]
26
+ exact (hp z).ne'
27
+ rw [he]
28
+ exact Measure.measure_univ_pos.mpr hμ
29
+
30
+ namespace Multipoint.CanonicalMass
31
+
32
+ local instance : LocallyCompactSpace upperHalfPlane := isOpen_upperHalfPlane.locallyCompactSpace
33
+
34
+ local instance positiveRestartDriverMeasurable : MeasurableSpace C(ℝ≥0,ℝ) := borel _
35
+ local instance positiveRestartDriverBorel : BorelSpace C(ℝ≥0,ℝ) := ⟨rfl⟩
36
+
37
+ variable {Ω : Type*} [mΩ : MeasurableSpace Ω] {P : Measure Ω} [IsProbabilityMeasure P] {κ : ℝ}
38
+ {B : ℝ≥0 → Ω → ℝ} {hBm : Measurable (Function.uncurry B)}
39
+ {γ : Ω → ℝ≥0 → ℂ} {G : Ω → ℝ≥0 → ℂ → ℂ}
40
+ (C : CanonicalMass P κ B hBm γ G)
41
+
42
+ lemma raw_restart_positive_time
43
+ (hB : IsBrownianReal B P) (hc : ∀ ω, Continuous (fun t => B t ω))
44
+ (R : RawCanonicalMass)
45
+ (he : ∀ᵐ ω ∂P, ∀ t, R.process t (sourceDriverPath B hc ω)=C.process t ω)
46
+ (hpos : ∀ᵐ ω ∂P, ∀ t : ℝ≥0, 0<t → C.process t ω≠0)
47
+ (τ : Ω → ℝ≥0)
48
+ (hτ : IsStoppingTime (Filtration.natural B (fun s =>
49
+ (hBm.comp (measurable_const.prodMk measurable_id) : Measurable (B s)).stronglyMeasurable))
50
+ (fun ω => (τ ω:WithTop ℝ≥0)))
51
+ (t : ℝ≥0) (ht : 0<t) :
52
+ ∀ᵐ ω ∂P, R.process t (sourceRestartDriverPath B hc τ ω)≠0 := by
53
+ let E : Set C(ℝ≥0,ℝ) := {p | 0<R.process t p univ}
54
+ have hEm : MeasurableSet E := measurableSet_lt measurable_const
55
+ ((Measure.measurable_coe MeasurableSet.univ).comp (R.progressive.adapted.measurable (i:=t)))
56
+ have hm (s : ℝ≥0) : Measurable (B s) := hBm.comp (measurable_const.prodMk measurable_id)
57
+ have hp := source_path_measurable (sourceDriverPath B hc) hm
58
+ have hEfull : ∀ᵐ p ∂P.map (sourceDriverPath B hc), p∈E := by
59
+ apply (ae_map_iff hp.aemeasurable hEm).mpr
60
+ filter_upwards [he,hpos] with ω hω hωp
61
+ rw [hω t]
62
+ exact Measure.measure_univ_pos.mpr (hωp t ht)
63
+ filter_upwards [sourceRestart_mem_full_driver_set hB hm hc τ hτ E hEm hEfull] with ω hω
64
+ exact Measure.measure_univ_pos.mp hω
65
+
66
+ lemma positive_increment_after_stop
67
+ (hB : IsBrownianReal B P) (hc : ∀ ω, Continuous (fun t => B t ω)) (hκ : 0<κ)
68
+ (F : Ω → ℝ≥0 → ℂ → ℂ)
69
+ (hw : ∀ ω, IsCapacityTwoWitness (fun t => Real.sqrt κ*B t ω) (γ ω) (G ω) (F ω))
70
+ (hpublished : PublishedTraceGeneration (P.map (sourceDriverPath B hc)) κ (fun t p => p t))
71
+ (hpos : ∀ᵐ ω ∂P, ∀ t : ℝ≥0, 0<t → C.process t ω≠0)
72
+ (τ : Ω → ℝ≥0)
73
+ (hτ : IsStoppingTime (Filtration.natural B (fun s =>
74
+ (hBm.comp (measurable_const.prodMk measurable_id) : Measurable (B s)).stronglyMeasurable))
75
+ (fun ω => (τ ω:WithTop ℝ≥0)))
76
+ (t : ℝ≥0) (ht : 0<t) :
77
+ ∀ᵐ ω ∂P, C.process (τ ω+t) ω-C.process (τ ω) ω≠0 := by
78
+ obtain ⟨R,he,hr⟩ := C.exists_raw_pathwise_restart hB hc hκ F hw hpublished
79
+ have hm (s : ℝ≥0) : Measurable (B s) := hBm.comp (measurable_const.prodMk measurable_id)
80
+ have hJ := stoppedMassPoint_measurable B κ γ G F hw τ hm hc hτ
81
+ have hW := stoppedMassWeight_measurable B κ γ G F hw τ hm hc hτ hκ
82
+ have hpair (ω : Ω) : @Measurable upperHalfPlane (Ω × upperHalfPlane) inferInstance
83
+ (hτ.measurableSpace.prod inferInstance) (fun z => (ω,z)) :=
84
+ @measurable_prodMk_left Ω upperHalfPlane hτ.measurableSpace inferInstance ω
85
+ have hJsec (ω : Ω) : Measurable (stoppedMassPoint B κ γ G F hw τ ω) :=
86
+ @Measurable.comp upperHalfPlane (Ω × upperHalfPlane) upperHalfPlane
87
+ inferInstance (hτ.measurableSpace.prod inferInstance) inferInstance
88
+ (fun p => stoppedMassPoint B κ γ G F hw τ p.1 p.2) (fun z => (ω,z)) hJ (hpair ω)
89
+ have hWsec (ω : Ω) : Measurable (stoppedMassWeight B κ F τ ω) :=
90
+ @Measurable.comp upperHalfPlane (Ω × upperHalfPlane) ℝ≥0∞
91
+ inferInstance (hτ.measurableSpace.prod inferInstance) inferInstance
92
+ (fun p => stoppedMassWeight B κ F τ p.1 p.2) (fun z => (ω,z)) hW (hpair ω)
93
+ filter_upwards [hr τ hτ,C.raw_restart_positive_time hB hc R (he.mono fun _ h => h.1)
94
+ hpos τ hτ t ht,fresh_capacity_witness_exists hB hm hc hpublished τ hτ] with ω hω hp hf
95
+ rw [hω.1 t]
96
+ obtain ⟨β,G',F',hf⟩ := hf
97
+ apply weightedImageMass_ne_zero (stoppedMassPoint B κ γ G F hw τ ω)
98
+ (hJsec ω)
99
+ (stoppedMassWeight B κ F τ ω)
100
+ (hWsec ω)
101
+ (fun z => ?_) _ hp
102
+ exact ENNReal.ofReal_pos.mpr (Real.rpow_pos_of_pos
103
+ ((hw ω).restart_inverse_derivative_norm_pos ((hc ω).const_mul _) (τ ω) hf z z.property) _)
104
+
105
+ lemma positive_increment_fixed_times
106
+ (hB : IsBrownianReal B P) (hc : ∀ ω, Continuous (fun t => B t ω)) (hκ : 0 < κ)
107
+ (F : Ω → ℝ≥0 → ℂ → ℂ)
108
+ (hw : ∀ ω, IsCapacityTwoWitness (fun t => Real.sqrt κ*B t ω) (γ ω) (G ω) (F ω))
109
+ (hpublished : PublishedTraceGeneration (P.map (sourceDriverPath B hc)) κ (fun t p => p t))
110
+ (hpos : ∀ᵐ ω ∂P, ∀ t : ℝ≥0, 0 < t → C.process t ω ≠ 0)
111
+ (s t : ℝ≥0) (hst : s < t) :
112
+ ∀ᵐ ω ∂P, C.process t ω-C.process s ω ≠ 0 := by
113
+ have hτ := isStoppingTime_const (Filtration.natural B (fun r =>
114
+ (hBm.comp (measurable_const.prodMk measurable_id) : Measurable (B r)).stronglyMeasurable)) s
115
+ have h := C.positive_increment_after_stop hB hc hκ F hw hpublished hpos
116
+ (fun _ => s) hτ (t-s) (tsub_pos_iff_lt.mpr hst)
117
+ simpa only [add_tsub_cancel_of_le hst.le] using h
118
+
119
+ lemma positive_increment_all_times
120
+ (hB : IsBrownianReal B P) (hc : ∀ ω, Continuous (fun t => B t ω)) (hκ : 0 < κ)
121
+ (F : Ω → ℝ≥0 → ℂ → ℂ)
122
+ (hw : ∀ ω, IsCapacityTwoWitness (fun t => Real.sqrt κ*B t ω) (γ ω) (G ω) (F ω))
123
+ (hpublished : PublishedTraceGeneration (P.map (sourceDriverPath B hc)) κ (fun t p => p t))
124
+ (hpos : ∀ᵐ ω ∂P, ∀ t : ℝ≥0, 0 < t → C.process t ω ≠ 0) :
125
+ ∀ᵐ ω ∂P, ∀ s t : ℝ≥0, s < t → C.process t ω-C.process s ω ≠ 0 := by
126
+ have hq (p q : ℚ) : ∀ᵐ ω ∂P,
127
+ (p:ℝ).toNNReal < (q:ℝ).toNNReal →
128
+ C.process (q:ℝ).toNNReal ω-C.process (p:ℝ).toNNReal ω ≠ 0 := by
129
+ by_cases hpq : (p:ℝ).toNNReal < (q:ℝ).toNNReal
130
+ · exact (C.positive_increment_fixed_times hB hc hκ F hw hpublished hpos _ _ hpq).mono
131
+ (fun _ h _ => h)
132
+ · exact ae_of_all _ (fun _ h => (hpq h).elim)
133
+ filter_upwards [C.paths,ae_all_iff.mpr (fun p => ae_all_iff.mpr (hq p))] with ω hp hqω
134
+ intro s t hst hz
135
+ obtain ⟨p,hsp,hpt⟩ := exists_rat_btwn (show (s:ℝ) < (t:ℝ) from hst)
136
+ obtain ⟨q,hpq,hqt⟩ := exists_rat_btwn hpt
137
+ have hp0 : (0:ℝ) ≤ p := s.coe_nonneg.trans hsp.le
138
+ have hq0 : (0:ℝ) ≤ q := hp0.trans hpq.le
139
+ have hsp' : s ≤ (p:ℝ).toNNReal := by
140
+ exact_mod_cast (show (s:ℝ) ≤ ((p:ℝ).toNNReal:ℝ) by rw [Real.coe_toNNReal _ hp0]; exact hsp.le)
141
+ have hpq' : (p:ℝ).toNNReal < (q:ℝ).toNNReal := by
142
+ exact_mod_cast (show ((p:ℝ).toNNReal:ℝ) < ((q:ℝ).toNNReal:ℝ) by
143
+ rw [Real.coe_toNNReal _ hp0,Real.coe_toNNReal _ hq0]; exact hpq)
144
+ have hqt' : (q:ℝ).toNNReal ≤ t := by
145
+ exact_mod_cast (show ((q:ℝ).toNNReal:ℝ) ≤ (t:ℝ) by rw [Real.coe_toNNReal _ hq0]; exact hqt.le)
146
+ let : IsFiniteMeasureOnCompacts (C.process s ω) := (C.radon s ω).2
147
+ have hts : C.process t ω=C.process s ω := by
148
+ have h := sigmaFinite_sub_add_cancel_of_le (hp.monotone hst.le)
149
+ rw [hz,zero_add] at h
150
+ exact h.symm
151
+ have hps : C.process (p:ℝ).toNNReal ω=C.process s ω := by
152
+ apply le_antisymm
153
+ · exact (hp.monotone (hpq'.le.trans hqt')).trans_eq hts
154
+ · exact hp.monotone hsp'
155
+ have hqs : C.process (q:ℝ).toNNReal ω=C.process s ω := by
156
+ apply le_antisymm
157
+ · exact (hp.monotone hqt').trans_eq hts
158
+ · exact hp.monotone (hsp'.trans hpq'.le)
159
+ apply hqω p q hpq'
160
+ rw [hps,hqs,Measure.sub_self]
161
+
162
+ end Multipoint.CanonicalMass
163
+ end SLEExactGauge
164
+
165
+ end
166
+
167
+ end OAI
lean/OAI/Probability/SLE/Mass/PositiveTraceMass.lean ADDED
@@ -0,0 +1,72 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Mass.PositiveRestartMass
2
+ import OAI.Probability.SLE.Mass.CanonicalMassScaling
3
+
4
+ namespace OAI
5
+
6
+ /-! Positive increments and trace support force positive canonical mass
7
+ in each open set visited at a positive time. -/
8
+
9
+ noncomputable section
10
+ open Set Filter _root_.MeasureTheory _root_.OAI.MeasureTheory ProbabilityTheory
11
+ open scoped Topology NNReal ENNReal
12
+
13
+ namespace SLEExactGauge.Multipoint
14
+
15
+ lemma positive_trace_mass_of_positive_increments
16
+ (γ : ℝ≥0 → ℂ) (hγ : Continuous γ) (N : ℝ≥0 → Measure upperHalfPlane)
17
+ (hmono : Monotone N)
18
+ (hinc : ∀ s t, s ≤ t → (N t-N s)
19
+ {z : upperHalfPlane | (z:ℂ) ∉ (fun r : ℝ => γ r.toNNReal) '' Icc (s:ℝ) t}=0)
20
+ (hpos : ∀ s t, s < t → N t-N s ≠ 0)
21
+ (V : Set ℂ) (hV : IsOpen V) (u T : ℝ≥0) (hu : 0 < u) (huT : u ≤ T)
22
+ (hvisit : γ u ∈ V) : 0 < N T (Subtype.val ⁻¹' V) := by
23
+ have hpre : γ ⁻¹' V ∈ 𝓝 u := hγ.continuousAt.preimage_mem_nhds (hV.mem_nhds hvisit)
24
+ obtain ⟨a,ha,haV⟩ := exists_Ioc_subset_of_mem_nhds' hpre hu
25
+ obtain ⟨b,hab,hbu⟩ := exists_between ha.2
26
+ have hseg : (fun r : ℝ => γ r.toNNReal) '' Icc (b:ℝ) u ⊆ V := by
27
+ rintro _ ⟨r,hr,rfl⟩
28
+ apply haV
29
+ have hbr : b ≤ r.toNNReal := by
30
+ simpa only [Real.toNNReal_coe] using Real.toNNReal_mono hr.1
31
+ have hru : r.toNNReal ≤ u := by
32
+ simpa only [Real.toNNReal_coe] using Real.toNNReal_mono hr.2
33
+ exact ⟨hab.trans_le hbr,hru⟩
34
+ have hnull : (N u-N b) (Subtype.val ⁻¹' V)ᶜ=0 := by
35
+ apply le_antisymm ?_ bot_le
36
+ apply (measure_mono (show (Subtype.val ⁻¹' V)ᶜ ⊆
37
+ {z : upperHalfPlane | (z:ℂ) ∉ (fun r : ℝ => γ r.toNNReal) '' Icc (b:ℝ) u} from ?_)).trans_eq
38
+ (hinc b u hbu.le)
39
+ intro z hz hs
40
+ exact hz (hseg hs)
41
+ have hVmeas : MeasurableSet ((Subtype.val : upperHalfPlane → ℂ) ⁻¹' V) :=
42
+ (hV.preimage (continuous_subtype_val : Continuous (Subtype.val : upperHalfPlane → ℂ))).measurableSet
43
+ have he := measure_add_measure_compl (μ:=N u-N b) hVmeas
44
+ rw [hnull,add_zero] at he
45
+ have hp : 0 < (N u-N b) (Subtype.val ⁻¹' V) := by
46
+ rw [he]
47
+ exact Measure.measure_univ_pos.mpr (hpos b u hbu)
48
+ exact hp.trans_le (((Measure.sub_le : N u-N b ≤ N u).trans (hmono huT)) _)
49
+
50
+ variable {Ω : Type*} [MeasurableSpace Ω] {P : Measure Ω} [IsProbabilityMeasure P]
51
+ {κ : ℝ} {B : ℝ≥0 → Ω → ℝ} {hBm : Measurable (Function.uncurry B)}
52
+ {γ : Ω → ℝ≥0 → ℂ} {G : Ω → ℝ≥0 → ℂ → ℂ}
53
+
54
+ lemma CanonicalMass.positive_open_visited
55
+ (C : CanonicalMass P κ B hBm γ G) (hB : IsBrownianReal B P)
56
+ (hc : ∀ ω, Continuous (fun t => B t ω)) (h0 : ∀ ω, B 0 ω=0) (hκ : 0 < κ)
57
+ (F : Ω → ℝ≥0 → ℂ → ℂ)
58
+ (hw : ∀ ω, IsCapacityTwoWitness (fun t => Real.sqrt κ*B t ω) (γ ω) (G ω) (F ω))
59
+ (hpublished : PublishedTraceGeneration (P.map (sourceDriverPath B hc)) κ (fun t p => p t)) :
60
+ ∀ᵐ ω ∂P, ∀ V : Set ℂ, IsOpen V → ∀ u T : ℝ≥0,
61
+ 0 < u → u ≤ T → γ ω u ∈ V → 0 < C.process T ω (Subtype.val ⁻¹' V) := by
62
+ have hp := C.positive_all_times hB hc h0 F hw
63
+ have hi := C.positive_increment_all_times hB hc hκ F hw hpublished hp
64
+ filter_upwards [C.paths,hi] with ω hω hωi
65
+ exact positive_trace_mass_of_positive_increments (γ ω) (hw ω).1 (fun t => C.process t ω)
66
+ hω.monotone hω.increment_support hωi
67
+
68
+ end SLEExactGauge.Multipoint
69
+
70
+ end
71
+
72
+ end OAI
lean/OAI/Probability/SLE/Mass/RadonApproximationList.lean ADDED
@@ -0,0 +1,56 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Mass.RadonTestLimit
2
+ import Mathlib.Topology.Bases
3
+ import Mathlib.Topology.Instances.Real.Lemmas
4
+
5
+ namespace OAI
6
+
7
+ /-! A countable list of positive Radon measures approximates every finite
8
+ list of compact-test integrals. This uses separability of the image in
9
+ real sequence space, without a topology on the space of measures. -/
10
+
11
+ noncomputable section
12
+ open Set Filter MeasureTheory Classical
13
+ open scoped Topology CompactlySupported
14
+
15
+ namespace SLEExactGauge
16
+
17
+ variable {X : Type*} [TopologicalSpace X] [T2Space X] [LocallyCompactSpace X]
18
+ [MeasurableSpace X] [BorelSpace X]
19
+
20
+ omit [T2Space X] [LocallyCompactSpace X] [BorelSpace X] in
21
+ lemma LocalTestFamily.exists_countable_measure_approximants (D : LocalTestFamily X) :
22
+ ∃ μ : ℕ → Measure X, (∀ k, (μ k).Regular) ∧
23
+ ∀ (ν : Measure X), ν.Regular → ∀ n : ℕ, ∀ ε : ℝ, 0 < ε →
24
+ ∃ k, ∀ j < n+1, |(∫ x, D.test j x ∂μ k)-(∫ x, D.test j x ∂ν)| < ε := by
25
+ let R := {ν : Measure X // ν.Regular}
26
+ let V : R → ℕ → ℝ := fun ν j => ∫ x, D.test j x ∂ν.val
27
+ let S := range V
28
+ let : Nonempty S := ⟨⟨V ⟨0,inferInstance⟩,⟨⟨0,inferInstance⟩,rfl⟩⟩⟩
29
+ let q : ℕ → S := TopologicalSpace.denseSeq S
30
+ have hq : DenseRange q := TopologicalSpace.denseRange_denseSeq S
31
+ choose μ hμ using fun k => (q k).property
32
+ refine ⟨fun k => (μ k).val,fun k => (μ k).property,?_⟩
33
+ intro ν hν n ε hε
34
+ let v : S := ⟨V ⟨ν,hν⟩,⟨⟨ν,hν⟩,rfl⟩⟩
35
+ let U : Set S := {w | ∀ j : Fin (n+1), |w.val j.val-v.val j.val| < ε}
36
+ have hU : IsOpen U := by
37
+ simp only [U,Set.ofPred_forall]
38
+ apply isOpen_iInter_of_finite
39
+ intro j
40
+ exact isOpen_lt (((continuous_apply j.val).comp continuous_subtype_val).sub continuous_const).abs
41
+ continuous_const
42
+ have hv : v ∈ U := by
43
+ intro j
44
+ simpa only [sub_self,abs_zero] using hε
45
+ obtain ⟨k,hk⟩ := hq.exists_mem_open hU ⟨v,hv⟩
46
+ refine ⟨k,fun j hj => ?_⟩
47
+ have hh := hk (⟨j,hj⟩ : Fin (n+1))
48
+ change |(V (μ k)) j-(V ⟨ν,hν⟩) j| < ε
49
+ rw [hμ k]
50
+ exact hh
51
+
52
+ end SLEExactGauge
53
+
54
+ end
55
+
56
+ end OAI
lean/OAI/Probability/SLE/Mass/RadonFactorization.lean ADDED
@@ -0,0 +1,97 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Mass.RadonApproximationList
2
+ import OAI.Probability.SLE.Mass.RawRadonLimit
3
+ import OAI.Probability.SLE.Mass.RadonTestDetermines
4
+ import Mathlib.MeasureTheory.Function.FactorsThrough
5
+
6
+ namespace OAI
7
+
8
+ /-! Doob--Dynkin factorization of a locally finite Radon kernel through
9
+ countably many real compact tests. The factor is regular on every input and
10
+ is reconstructed in the target data space, without ambient null-set changes. -/
11
+
12
+ noncomputable section
13
+ open Set Filter MeasureTheory Classical
14
+ open scoped Topology CompactlySupported
15
+
16
+ namespace SLEExactGauge
17
+
18
+ lemma exists_measurable_nat_choice
19
+ {Y : Type*} [MeasurableSpace Y] (p : Y → ℕ → Prop)
20
+ (hm : ∀ k, MeasurableSet {y | p y k}) :
21
+ ∃ i : Y → ℕ, Measurable i ∧ ∀ y, (∃ k, p y k) → p y (i y) := by
22
+ let q (y : Y) (k : ℕ) := (∃ j, p y j) → p y k
23
+ have hq (y : Y) : ∃ k, q y k := by
24
+ by_cases h : ∃ j, p y j
25
+ · obtain ⟨k,hk⟩ := h
26
+ exact ⟨k,fun _ => hk⟩
27
+ · exact ⟨0,fun h' => (h h').elim⟩
28
+ have hqm (k : ℕ) : MeasurableSet {y | q y k} := by
29
+ have he : {y | q y k} = (⋃ j, {y | p y j})ᶜ ∪ {y | p y k} := by
30
+ ext y
31
+ simp only [q,mem_ofPred_eq,mem_union,mem_compl_iff,mem_iUnion]
32
+ tauto
33
+ rw [he]
34
+ exact (MeasurableSet.iUnion hm).compl.union (hm k)
35
+ exact ⟨fun y => Nat.find (hq y),measurable_find hq hqm,
36
+ fun y hy => Nat.find_spec (hq y) hy⟩
37
+
38
+ variable {X : Type*} [TopologicalSpace X] [T2Space X] [LocallyCompactSpace X]
39
+ [SecondCountableTopology X] [MeasurableSpace X] [BorelSpace X]
40
+
41
+ /-- Countable compact tests suffice for a raw measurable Radon factor.
42
+ The factorization equality holds at every original input. -/
43
+ theorem LocalTestFamily.measurable_radon_factor
44
+ (D : LocalTestFamily X) {Ω Y : Type*} [MeasurableSpace Y]
45
+ (F : Ω → Y) (μ : Ω → Measure X) (hμ : ∀ ω, (μ ω).Regular)
46
+ (htest : ∀ j, Measurable[MeasurableSpace.comap F inferInstance]
47
+ (fun ω => ∫ x, D.test j x ∂μ ω)) :
48
+ ∃ ν : Y → Measure X, Measurable ν ∧ (∀ y, (ν y).Regular) ∧ ∀ ω, ν (F ω)=μ ω := by
49
+ choose g hgm hg using fun j => (htest j).exists_eq_measurable_comp
50
+ obtain ⟨a,ha,happrox⟩ := D.exists_countable_measure_approximants
51
+ let p (n : ℕ) (y : Y) (k : ℕ) : Prop :=
52
+ ∀ j < n+1, |(∫ x, D.test j x ∂a k)-g j y| < 1/(n+1:ℝ)
53
+ have hpm (n k : ℕ) : MeasurableSet {y | p n y k} := by
54
+ simp only [p,Set.ofPred_forall]
55
+ apply MeasurableSet.iInter
56
+ intro j
57
+ apply MeasurableSet.iInter
58
+ intro _
59
+ simpa only [Real.norm_eq_abs,Pi.sub_apply] using
60
+ measurableSet_lt (measurable_const.sub (hgm j)).norm measurable_const
61
+ choose i him hi using fun n => exists_measurable_nat_choice (p n) (hpm n)
62
+ let μn (n : ℕ) (y : Y) := a (i n y)
63
+ have hμnm (n : ℕ) (f : C_c(X,ℝ)) : Measurable (fun y => ∫ x, f x ∂μn n y) :=
64
+ (measurable_of_countable (fun k => ∫ x, f x ∂a k)).comp (him n)
65
+ have hvalid (n : ℕ) (ω : Ω) : p n (F ω) (i n (F ω)) := by
66
+ apply hi n
67
+ obtain ⟨k,hk⟩ := happrox (μ ω) (hμ ω) n (1/(n+1:ℝ)) (by positivity)
68
+ refine ⟨k,fun j hj => ?_⟩
69
+ have he : g j (F ω) = ∫ x, D.test j x ∂μ ω := congr_fun (hg j) ω |>.symm
70
+ rw [he]
71
+ exact hk j hj
72
+ have hlim (ω : Ω) (j : ℕ) : Tendsto (fun n => ∫ x, D.test j x ∂μn n (F ω)) atTop
73
+ (𝓝 (∫ x, D.test j x ∂μ ω)) := by
74
+ apply Metric.tendsto_atTop.mpr
75
+ intro ε hε
76
+ obtain ⟨N,hN⟩ := eventually_atTop.mp
77
+ ((tendsto_one_div_add_atTop_nhds_zero_nat (𝕜 := ℝ)).eventually (gt_mem_nhds hε))
78
+ refine ⟨max j N,fun n hn => ?_⟩
79
+ rw [Real.dist_eq]
80
+ have hjn : j < n+1 := by omega
81
+ have hv := hvalid n ω j hjn
82
+ have he : g j (F ω) = ∫ x, D.test j x ∂μ ω := congr_fun (hg j) ω |>.symm
83
+ rw [he] at hv
84
+ exact hv.trans (hN n (le_trans (le_max_right _ _) hn))
85
+ obtain ⟨ν,hνm,hν,hνlim⟩ := D.exists_raw_radon_limit μn (fun n y => ha (i n y)) hμnm
86
+ refine ⟨ν,hνm,hν,fun ω => ?_⟩
87
+ let := hν (F ω)
88
+ let := hμ ω
89
+ apply D.measure_eq_of_test_integrals
90
+ intro j
91
+ exact tendsto_nhds_unique (hνlim (F ω) (fun j => (hlim ω j).cauchySeq) (D.test j)) (hlim ω j)
92
+
93
+ end SLEExactGauge
94
+
95
+ end
96
+
97
+ end OAI
lean/OAI/Probability/SLE/Mass/RadonKernelIntegral.lean ADDED
@@ -0,0 +1,67 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import Mathlib.MeasureTheory.Measure.GiryMonad
2
+ import Mathlib.MeasureTheory.Integral.Bochner.Basic
3
+
4
+ namespace OAI
5
+
6
+ /-! Signed integrals of a random Radon measure can be computed from its
7
+ mean measure. The positive and negative parts use Tonelli separately. -/
8
+
9
+ noncomputable section
10
+ open Set Filter MeasureTheory
11
+ open scoped ENNReal
12
+
13
+ namespace SLEExactGauge
14
+
15
+ lemma lintegral_ofReal_lt_top_of_integrable
16
+ {X : Type*} [MeasurableSpace X] {μ : Measure X} {f : X → ℝ}
17
+ (hf : Integrable f μ) : (∫⁻ x, ENNReal.ofReal (f x) ∂μ) < ⊤ := by
18
+ apply (lintegral_mono (fun x => ENNReal.ofReal_le_ofReal (le_abs_self (f x)))).trans_lt
19
+ exact (hasFiniteIntegral_iff_ofReal (Eventually.of_forall (fun x => norm_nonneg (f x)))).mp
20
+ hf.norm.hasFiniteIntegral
21
+
22
+ theorem integrable_integral_bind_of_sections
23
+ {Ω X : Type*} [MeasurableSpace Ω] [MeasurableSpace X]
24
+ (P : Measure Ω) (μ : Ω → Measure X) (hμ : Measurable μ)
25
+ (f : X → ℝ) (hf : Measurable f)
26
+ (hfi : ∀ ω, Integrable f (μ ω)) (hfP : Integrable f (P.bind μ)) :
27
+ Integrable (fun ω => ∫ x, f x ∂μ ω) P ∧
28
+ (∫ ω, (∫ x, f x ∂μ ω) ∂P) = ∫ x, f x ∂P.bind μ := by
29
+ let A (ω : Ω) := ∫⁻ x, ENNReal.ofReal (f x) ∂μ ω
30
+ let B (ω : Ω) := ∫⁻ x, ENNReal.ofReal (-f x) ∂μ ω
31
+ have hAm : Measurable A := (Measure.measurable_lintegral hf.ennreal_ofReal).comp hμ
32
+ have hBm : Measurable B := (Measure.measurable_lintegral hf.neg.ennreal_ofReal).comp hμ
33
+ have hA : (∫⁻ ω, A ω ∂P) = ∫⁻ x, ENNReal.ofReal (f x) ∂P.bind μ :=
34
+ (Measure.lintegral_bind hμ.aemeasurable hf.ennreal_ofReal.aemeasurable).symm
35
+ have hB : (∫⁻ ω, B ω ∂P) = ∫⁻ x, ENNReal.ofReal (-f x) ∂P.bind μ :=
36
+ (Measure.lintegral_bind hμ.aemeasurable hf.neg.ennreal_ofReal.aemeasurable).symm
37
+ have hAf : (∫⁻ ω, A ω ∂P) < ⊤ := hA.trans_lt (lintegral_ofReal_lt_top_of_integrable hfP)
38
+ have hBf : (∫⁻ ω, B ω ∂P) < ⊤ := hB.trans_lt (lintegral_ofReal_lt_top_of_integrable hfP.neg)
39
+ have he (ω : Ω) : (∫ x, f x ∂μ ω) = (A ω).toReal - (B ω).toReal :=
40
+ integral_eq_lintegral_pos_part_sub_lintegral_neg_part (hfi ω)
41
+ refine ⟨?_,?_⟩
42
+ · convert (integrable_toReal_of_lintegral_ne_top hAm.aemeasurable hAf.ne).sub
43
+ (integrable_toReal_of_lintegral_ne_top hBm.aemeasurable hBf.ne) using 1
44
+ funext ω
45
+ exact he ω
46
+ simp_rw [he]
47
+ rw [integral_sub (integrable_toReal_of_lintegral_ne_top hAm.aemeasurable hAf.ne)
48
+ (integrable_toReal_of_lintegral_ne_top hBm.aemeasurable hBf.ne),
49
+ integral_toReal hAm.aemeasurable (Eventually.of_forall (fun ω =>
50
+ lintegral_ofReal_lt_top_of_integrable (hfi ω))),
51
+ integral_toReal hBm.aemeasurable (Eventually.of_forall (fun ω =>
52
+ lintegral_ofReal_lt_top_of_integrable (hfi ω).neg)),hA,hB]
53
+ exact (integral_eq_lintegral_pos_part_sub_lintegral_neg_part hfP).symm
54
+
55
+ theorem integral_bind_of_integrable_sections
56
+ {Ω X : Type*} [MeasurableSpace Ω] [MeasurableSpace X]
57
+ (P : Measure Ω) (μ : Ω → Measure X) (hμ : Measurable μ)
58
+ (f : X → ℝ) (hf : Measurable f)
59
+ (hfi : ∀ ω, Integrable f (μ ω)) (hfP : Integrable f (P.bind μ)) :
60
+ (∫ ω, (∫ x, f x ∂μ ω) ∂P) = ∫ x, f x ∂P.bind μ :=
61
+ (integrable_integral_bind_of_sections P μ hμ f hf hfi hfP).2
62
+
63
+ end SLEExactGauge
64
+
65
+ end
66
+
67
+ end OAI
lean/OAI/Probability/SLE/Mass/RadonPathCertificates.lean ADDED
@@ -0,0 +1,77 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Mass.RadonTestDetermines
2
+ import OAI.Probability.SLE.Mass.RadonTestLimitProperties
3
+ import OAI.Probability.SLE.Mass.RationalTraceMassProgressiveVersion
4
+
5
+ namespace OAI
6
+
7
+ /-! Countable compact-test certificates for order and continuous Radon paths.
8
+ The cutoff coordinates in the determining family supply local mass bounds. -/
9
+
10
+ noncomputable section
11
+ open Set Filter MeasureTheory
12
+ open scoped Topology CompactlySupported NNReal
13
+
14
+ namespace SLEExactGauge
15
+
16
+ variable {X : Type*} [TopologicalSpace X] [T2Space X] [LocallyCompactSpace X]
17
+ [MeasurableSpace X] [BorelSpace X]
18
+
19
+ private lemma positive_part_error {a b e : ℝ} (ha : 0 ≤ a) (h : |a-b| ≤ e) :
20
+ |a-max b 0| ≤ e := by
21
+ rcases le_total 0 b with hb | hb
22
+ · simpa only [max_eq_left hb] using h
23
+ · rw [max_eq_right hb,sub_zero,abs_of_nonneg ha]
24
+ rw [abs_of_nonneg (sub_nonneg.mpr (hb.trans ha))] at h
25
+ linarith
26
+
27
+ theorem LocalTestFamily.measure_le_of_positive_tests (D : LocalTestFamily X)
28
+ (μ ν : Measure X) [μ.Regular] [ν.Regular]
29
+ (h : ∀ j, (∫ x, (D.test j ⊔ 0) x ∂μ) ≤ ∫ x, (D.test j ⊔ 0) x ∂ν) : μ ≤ ν := by
30
+ apply radon_measure_le_of_nonneg_tests
31
+ intro f hf
32
+ obtain ⟨k,_,happrox⟩ := D.weighted_approximation f
33
+ let A := ∫ x, f x ∂μ
34
+ let B := ∫ x, f x ∂ν
35
+ let M := (∫ x, D.test k x ∂μ)+(∫ x, D.test k x ∂ν)
36
+ have hb (n : ℕ) : A ≤ B+(1/(n+1:ℝ))*M := by
37
+ obtain ⟨j,hj⟩ := happrox (1/(n+1:ℝ)) (by positivity)
38
+ have hp (x : X) : |f x-(D.test j ⊔ 0) x| ≤ (1/(n+1:ℝ))*D.test k x :=
39
+ positive_part_error (hf x) (hj x)
40
+ have hμ := integral_sub_le_cutoff μ f (D.test j ⊔ 0) (D.test k) _ hp
41
+ have hν := integral_sub_le_cutoff ν f (D.test j ⊔ 0) (D.test k) _ hp
42
+ have hh := h j
43
+ dsimp only [A,B,M]
44
+ have hμ' := le_abs_self ((∫ x, f x ∂μ)-(∫ x, (D.test j ⊔ 0) x ∂μ))
45
+ have hν' := neg_le_abs ((∫ x, f x ∂ν)-(∫ x, (D.test j ⊔ 0) x ∂ν))
46
+ nlinarith
47
+ have hl : Tendsto (fun n : ℕ => B+(1/(n+1:ℝ))*M) atTop (𝓝 B) := by
48
+ simpa only [zero_mul,add_zero] using tendsto_const_nhds.add
49
+ ((tendsto_one_div_add_atTop_nhds_zero_nat (𝕜 := ℝ)).mul_const M)
50
+ exact le_of_tendsto_of_tendsto' tendsto_const_nhds hl hb
51
+
52
+ theorem LocalTestFamily.continuous_integrals_of_tests (D : LocalTestFamily X)
53
+ {T : Type*} [TopologicalSpace T] [SequentialSpace T]
54
+ (N : T → Measure X) (hr : ∀ t, (N t).Regular)
55
+ (hc : ∀ j, Continuous (fun t => ∫ x, D.test j x ∂N t)) :
56
+ ∀ f : C_c(X,ℝ), Continuous (fun t => ∫ x, f x ∂N t) := by
57
+ intro f
58
+ apply SeqContinuous.continuous
59
+ intro t a hta
60
+ let (n : ℕ) : IsFiniteMeasureOnCompacts (N (t n)) := by
61
+ let := hr (t n)
62
+ infer_instance
63
+ obtain ⟨ν,hν,_,hl⟩ := D.exists_radon_limit (fun n => N (t n))
64
+ (fun j => ⟨∫ x, D.test j x ∂N a,(hc j).continuousAt.tendsto.comp hta⟩)
65
+ have he : ν=N a := by
66
+ let := hν
67
+ let := hr a
68
+ apply D.measure_eq_of_test_integrals
69
+ intro j
70
+ exact tendsto_nhds_unique (hl (D.test j)) ((hc j).continuousAt.tendsto.comp hta)
71
+ simpa only [he,Function.comp_def] using hl f
72
+
73
+ end SLEExactGauge
74
+
75
+ end
76
+
77
+ end OAI
lean/OAI/Probability/SLE/Mass/RadonProcessAEUniqueness.lean ADDED
@@ -0,0 +1,39 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Mass.RadonProcessUniqueness
2
+
3
+ namespace OAI
4
+
5
+ /-! A single almost-sure Radon certificate suffices when upgrading
6
+ simultaneous positive-test identities to identities of measure paths. -/
7
+
8
+ noncomputable section
9
+ open Set Filter MeasureTheory
10
+ open scoped Topology CompactlySupported NNReal
11
+
12
+ namespace SLEExactGauge
13
+
14
+ theorem random_radon_process_eq_of_positive_tests_ae
15
+ {X : Type*} [TopologicalSpace X] [T2Space X] [LocallyCompactSpace X]
16
+ [MeasurableSpace X] [BorelSpace X]
17
+ {Ω : Type*} [MeasurableSpace Ω] (P : Measure Ω)
18
+ (D : LocalTestFamily X) (N M : ℝ≥0 → Ω → Measure X)
19
+ (hNr : ∀ᵐ ω ∂P, ∀ t, (N t ω).Regular)
20
+ (hMr : ∀ᵐ ω ∂P, ∀ t, (M t ω).Regular)
21
+ (htest : ∀ f : C_c(X,ℝ), (∀ x, 0 ≤ f x) →
22
+ ∀ᵐ ω ∂P, ∀ t, (∫ x, f x ∂N t ω)=∫ x, f x ∂M t ω) :
23
+ ∀ᵐ ω ∂P, ∀ t, N t ω=M t ω := by
24
+ have hp (j : ℕ) := htest (D.test j ⊔ 0) (fun x => le_max_right _ _)
25
+ have hn (j : ℕ) := htest ((-D.test j) ⊔ 0) (fun x => le_max_right _ _)
26
+ filter_upwards [hNr,hMr,ae_all_iff.mpr hp,ae_all_iff.mpr hn] with ω hN hM hωp hωn
27
+ intro t
28
+ let := hN t
29
+ let := hM t
30
+ apply D.measure_eq_of_test_integrals
31
+ intro j
32
+ rw [compact_test_integral_pos_sub_neg (N t ω) (D.test j),
33
+ compact_test_integral_pos_sub_neg (M t ω) (D.test j),hωp j t,hωn j t]
34
+
35
+ end SLEExactGauge
36
+
37
+ end
38
+
39
+ end OAI
lean/OAI/Probability/SLE/Mass/RadonProcessUniqueness.lean ADDED
@@ -0,0 +1,51 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Mass.MassKernelUniqueness
2
+ import OAI.Probability.SLE.Mass.RadonTestDetermines
3
+
4
+ namespace OAI
5
+
6
+ /-! Countably many positive compact tests give one common full-measure event
7
+ on which all times of two random Radon processes agree. -/
8
+
9
+ noncomputable section
10
+ open Set Filter MeasureTheory
11
+ open scoped Topology CompactlySupported NNReal
12
+
13
+ namespace SLEExactGauge
14
+
15
+ variable {X : Type*} [TopologicalSpace X] [T2Space X] [LocallyCompactSpace X]
16
+ [MeasurableSpace X] [BorelSpace X]
17
+
18
+ omit [T2Space X] [LocallyCompactSpace X] in
19
+ lemma compact_test_integral_pos_sub_neg (μ : Measure X) [μ.Regular] (f : C_c(X,ℝ)) :
20
+ (∫ x, f x ∂μ) = (∫ x, (f ⊔ 0) x ∂μ)-(∫ x, ((-f) ⊔ 0) x ∂μ) := by
21
+ rw [← integral_sub (f ⊔ 0).integrable ((-f) ⊔ 0).integrable]
22
+ apply integral_congr_ae
23
+ filter_upwards [] with x
24
+ change f x = max (f x) 0-max (-f x) 0
25
+ rcases le_total 0 (f x) with h | h
26
+ · rw [max_eq_left h,max_eq_right (neg_nonpos.mpr h),sub_zero]
27
+ · rw [max_eq_right h,max_eq_left (neg_nonneg.mpr h),zero_sub,neg_neg]
28
+
29
+ theorem random_radon_process_eq_of_positive_tests
30
+ {Ω : Type*} [MeasurableSpace Ω] (P : Measure Ω)
31
+ (D : LocalTestFamily X) (N M : ℝ≥0 → Ω → Measure X)
32
+ (hNr : ∀ t ω, (N t ω).Regular) (hMr : ∀ t ω, (M t ω).Regular)
33
+ (htest : ∀ f : C_c(X,ℝ), (∀ x, 0 ≤ f x) →
34
+ ∀ᵐ ω ∂P, ∀ t, (∫ x, f x ∂N t ω) = ∫ x, f x ∂M t ω) :
35
+ ∀ᵐ ω ∂P, ∀ t, N t ω = M t ω := by
36
+ have hp (j : ℕ) := htest (D.test j ⊔ 0) (fun x => le_max_right _ _)
37
+ have hn (j : ℕ) := htest ((-D.test j) ⊔ 0) (fun x => le_max_right _ _)
38
+ filter_upwards [ae_all_iff.mpr hp,ae_all_iff.mpr hn] with ω hωp hωn
39
+ intro t
40
+ let := hNr t ω
41
+ let := hMr t ω
42
+ apply D.measure_eq_of_test_integrals
43
+ intro j
44
+ rw [compact_test_integral_pos_sub_neg (N t ω) (D.test j),
45
+ compact_test_integral_pos_sub_neg (M t ω) (D.test j),hωp j t,hωn j t]
46
+
47
+ end SLEExactGauge
48
+
49
+ end
50
+
51
+ end OAI
lean/OAI/Probability/SLE/Mass/RadonRandomTesting.lean ADDED
@@ -0,0 +1,64 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Geometry.RandomSpatialTesting
2
+ import OAI.Probability.SLE.LoewnerCharts
3
+
4
+ namespace OAI
5
+
6
+ /-! Nonnegative random tests of locally finite half-plane measures.
7
+ Compact restrictions remove any need for a finite total mass. -/
8
+
9
+ noncomputable section
10
+ open Set Filter MeasureTheory ProbabilityTheory Classical
11
+ open scoped ENNReal
12
+
13
+ namespace SLEExactGauge
14
+
15
+ local instance : LocallyCompactSpace upperHalfPlane := isOpen_upperHalfPlane.locallyCompactSpace
16
+
17
+ private lemma finite_halfPlane_random_test_measurable
18
+ {Ω : Type*} [MeasurableSpace Ω]
19
+ (μ : Ω → Measure upperHalfPlane) (hμ : Measurable μ)
20
+ (hfin : ∀ ω, IsFiniteMeasure (μ ω))
21
+ (f : Ω × upperHalfPlane → ℝ≥0∞) (hf : Measurable f) :
22
+ Measurable (fun ω => ∫⁻ z, f (ω,z) ∂μ ω) := by
23
+ let K : Kernel Ω upperHalfPlane := ⟨μ,hμ⟩
24
+ have hp : Measurable (fun ω => (μ ω).map (Prod.mk ω)) := by
25
+ apply Measure.measurable_of_measurable_coe
26
+ intro A hA
27
+ have h := Kernel.measurable_kernel_prodMk_left_of_finite (κ := K) hA hfin
28
+ change Measurable (fun a => μ a (Prod.mk a ⁻¹' A)) at h
29
+ simpa only [Measure.map_apply measurable_prodMk_left hA] using h
30
+ have h := (Measure.measurable_lintegral hf).comp hp
31
+ convert h using 1
32
+ funext ω
33
+ exact (lintegral_map hf measurable_prodMk_left).symm
34
+
35
+ theorem halfPlane_random_test_measurable
36
+ {Ω : Type*} [MeasurableSpace Ω]
37
+ (μ : Ω → Measure upperHalfPlane) (hμ : Measurable μ)
38
+ (hfin : ∀ ω, IsFiniteMeasureOnCompacts (μ ω))
39
+ (f : Ω × upperHalfPlane → ℝ≥0∞) (hf : Measurable f) :
40
+ Measurable (fun ω => ∫⁻ z, f (ω,z) ∂μ ω) := by
41
+ have he (ω : Ω) : (∫⁻ z, f (ω,z) ∂μ ω) =
42
+ ⨆ n, ∫⁻ z in compactCovering upperHalfPlane n, f (ω,z) ∂μ ω := by
43
+ rw [← setLIntegral_iUnion_of_directed _ (Monotone.directed_le (compactCovering_subset upperHalfPlane)),
44
+ iUnion_compactCovering,Measure.restrict_univ]
45
+ simp_rw [he]
46
+ apply Measurable.iSup
47
+ intro n
48
+ have hK := (isCompact_compactCovering upperHalfPlane n).measurableSet
49
+ have hm : Measurable (fun ω => (μ ω).restrict (compactCovering upperHalfPlane n)) := by
50
+ apply Measure.measurable_of_measurable_coe
51
+ intro A hA
52
+ simp only [Measure.restrict_apply hA]
53
+ exact (Measure.measurable_coe (hA.inter hK)).comp hμ
54
+ apply finite_halfPlane_random_test_measurable _ hm _ f hf
55
+ intro ω
56
+ let := hfin ω
57
+ exact ⟨by simpa only [Measure.restrict_apply_univ] using
58
+ (isCompact_compactCovering upperHalfPlane n).measure_lt_top (μ := μ ω)⟩
59
+
60
+ end SLEExactGauge
61
+
62
+ end
63
+
64
+ end OAI
lean/OAI/Probability/SLE/Mass/RadonTerminalUniqueness.lean ADDED
@@ -0,0 +1,49 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Mass.RadonProcessUniqueness
2
+ import OAI.Probability.SLE.Mass.RationalTraceMassLocalVariation
3
+ import OAI.Probability.SLE.Mass.LocallyFiniteMeasureSubtract
4
+
5
+ namespace OAI
6
+
7
+ /-! Local exhaustion determines the terminal measure once the finite-time
8
+ increasing Radon family is fixed. -/
9
+
10
+ noncomputable section
11
+ open Set Filter MeasureTheory
12
+ open scoped ENNReal NNReal Topology
13
+
14
+ namespace SLEExactGauge
15
+
16
+ lemma radon_terminal_eq_of_common_exhaustion
17
+ {X : Type*} [TopologicalSpace X] [T2Space X] [LocallyCompactSpace X]
18
+ [MeasurableSpace X] [BorelSpace X]
19
+ (μ ν : Measure X) [μ.Regular] [ν.Regular]
20
+ (N : ℝ≥0 → Measure X)
21
+ (hμ : ∀ t, N t ≤ μ) (hν : ∀ t, N t ≤ ν)
22
+ (hlμ : ∀ K : Set X, IsCompact K → Tendsto (fun t : ℝ≥0 => (μ-N t) K) atTop (𝓝 0))
23
+ (hlν : ∀ K : Set X, IsCompact K → Tendsto (fun t : ℝ≥0 => (ν-N t) K) atTop (𝓝 0)) :
24
+ μ = ν := by
25
+ have hle (ρ σ : Measure X) [ρ.Regular] (hρ : ∀ t, N t ≤ ρ) (hσ : ∀ t, N t ≤ σ)
26
+ (hl : ∀ K : Set X, IsCompact K → Tendsto (fun t : ℝ≥0 => (ρ-N t) K) atTop (𝓝 0))
27
+ (K : Set X) (hK : IsCompact K) : ρ K ≤ σ K := by
28
+ have hb (t : ℝ≥0) : ρ K ≤ σ K+(ρ-N t) K := by
29
+ let : IsFiniteMeasureOnCompacts (N t) :=
30
+ ⟨fun L hL => lt_of_le_of_lt (hρ t L) hL.measure_lt_top⟩
31
+ rw [sub_apply_of_finite_restriction (hρ t) hK.measurableSet hK.measure_lt_top.ne]
32
+ calc
33
+ ρ K = (ρ K-N t K)+N t K := (tsub_add_cancel_of_le (hρ t K)).symm
34
+ _ ≤ (ρ K-N t K)+σ K := add_le_add le_rfl (hσ t K)
35
+ _ = _ := add_comm _ _
36
+ have hlim := (tendsto_const_nhds (x := σ K)).add (hl K hK)
37
+ simp only [add_zero] at hlim
38
+ exact le_of_tendsto_of_tendsto' tendsto_const_nhds hlim hb
39
+ apply Measure.OuterRegular.ext_isOpen
40
+ apply Measure.InnerRegularWRT.eq_of_innerRegularWRT_of_forall_eq
41
+ Measure.Regular.innerRegular Measure.Regular.innerRegular
42
+ intro K hK
43
+ exact (hle μ ν hμ hν hlμ K hK).antisymm (hle ν μ hν hμ hlν K hK)
44
+
45
+ end SLEExactGauge
46
+
47
+ end
48
+
49
+ end OAI
lean/OAI/Probability/SLE/Mass/RadonTestDetermines.lean ADDED
@@ -0,0 +1,49 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Mass.RadonTestLimit
2
+
3
+ namespace OAI
4
+
5
+ /-! The constructed countable local family determines a regular measure. -/
6
+
7
+ noncomputable section
8
+ open Set Filter MeasureTheory
9
+ open scoped Topology CompactlySupported
10
+
11
+ namespace SLEExactGauge
12
+
13
+ variable {X : Type*} [TopologicalSpace X] [T2Space X] [LocallyCompactSpace X]
14
+ [MeasurableSpace X] [BorelSpace X]
15
+
16
+ theorem LocalTestFamily.measure_eq_of_test_integrals (D : LocalTestFamily X)
17
+ (μ ν : Measure X) [μ.Regular] [ν.Regular]
18
+ (h : ∀ j, (∫ x, D.test j x ∂μ) = ∫ x, D.test j x ∂ν) : μ = ν := by
19
+ apply Measure.ext_of_integral_eq_on_compactlySupported
20
+ intro f
21
+ let M (n : ℕ) := if n % 2 = 0 then μ else ν
22
+ let (n : ℕ) : IsFiniteMeasureOnCompacts (M n) := by
23
+ dsimp only [M]
24
+ split_ifs <;> infer_instance
25
+ have hc : CauchySeq (fun n => ∫ x, f x ∂M n) := D.integrals_cauchy M (fun j => by
26
+ refine ⟨∫ x, D.test j x ∂ν,?_⟩
27
+ have he : (fun n => ∫ x, D.test j x ∂M n) = fun _ => ∫ x, D.test j x ∂ν := by
28
+ funext n
29
+ dsimp only [M]
30
+ split_ifs
31
+ · exact h j
32
+ · rfl
33
+ rw [he]
34
+ exact tendsto_const_nhds) f
35
+ apply eq_of_dist_eq_zero
36
+ apply le_antisymm _ dist_nonneg
37
+ apply le_of_forall_pos_le_add
38
+ intro ε hε
39
+ obtain ⟨N,hN⟩ := Metric.cauchySeq_iff.mp hc ε hε
40
+ have hh := hN (2*N) (by omega) (2*N+1) (by omega)
41
+ have hm0 : (2*N)%2=0 := by omega
42
+ have hm1 : (2*N+1)%2≠0 := by omega
43
+ simpa only [M,hm0,hm1,ite_true,ite_false,zero_add] using hh.le
44
+
45
+ end SLEExactGauge
46
+
47
+ end
48
+
49
+ end OAI
lean/OAI/Probability/SLE/Mass/RadonTestFamily.lean ADDED
@@ -0,0 +1,118 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Mass.RadonTestLimit
2
+ import Mathlib.Topology.ContinuousMap.SecondCountableSpace
3
+ import Mathlib.Topology.UrysohnsLemma
4
+
5
+ namespace OAI
6
+
7
+ /-! A countable determining family on a second-countable locally compact
8
+ space, constructed from compact exhaustion and separability on compacts. -/
9
+
10
+ noncomputable section
11
+ open Set Filter MeasureTheory
12
+ open scoped Topology CompactlySupported
13
+
14
+ namespace SLEExactGauge
15
+
16
+ variable {X : Type*} [TopologicalSpace X] [T2Space X] [LocallyCompactSpace X]
17
+ [SecondCountableTopology X]
18
+
19
+ omit [LocallyCompactSpace X] in
20
+ /-- Compact support in a fixed compact set admits a countable uniformly
21
+ dense family, with the same support constraint. -/
22
+ theorem exists_compact_test_sequence (K : Set X) (hK : IsCompact K) :
23
+ ∃ f : ℕ → C_c(X, ℝ), (∀ j, tsupport (f j) ⊆ K) ∧
24
+ ∀ g : C_c(X, ℝ), tsupport g ⊆ K → ∀ ε : ℝ, 0 < ε →
25
+ ∃ j, ∀ x, |g x-f j x| ≤ ε := by
26
+ classical
27
+ let : CompactSpace K := isCompact_iff_compactSpace.mp hK
28
+ let S : Set C(K, ℝ) := {g | ∃ f : C_c(X, ℝ), tsupport f ⊆ K ∧ ∀ x : K, g x=f x}
29
+ have hzero : (0 : C(K, ℝ)) ∈ S := by
30
+ refine ⟨0, ?_, fun _ => rfl⟩
31
+ simp
32
+ let : Nonempty S := ⟨⟨0,hzero⟩⟩
33
+ obtain ⟨d,hd⟩ := TopologicalSpace.exists_dense_seq S
34
+ have hrep (j : ℕ) : ∃ f : C_c(X, ℝ), tsupport f ⊆ K ∧ ∀ x : K, (d j).1 x=f x :=
35
+ (d j).2
36
+ choose f hf hrep using hrep
37
+ refine ⟨f,hf,fun g hg ε hε => ?_⟩
38
+ let r : C(K, ℝ) := ⟨fun x => g x, g.continuous.comp continuous_subtype_val⟩
39
+ have hr : r ∈ S := ⟨g,hg,fun _ => rfl⟩
40
+ obtain ⟨j,hj⟩ := Metric.denseRange_iff.mp hd ⟨r,hr⟩ ε hε
41
+ refine ⟨j,fun x => ?_⟩
42
+ by_cases hx : x ∈ K
43
+ · have hb := ContinuousMap.norm_coe_le_norm (r-(d j).1) ⟨x,hx⟩
44
+ have hb' : |g x-f j x| ≤ dist (⟨r,hr⟩ : S) (d j) := by
45
+ change |g x-f j x| ≤ dist r (d j).1
46
+ rw [dist_eq_norm]
47
+ simpa only [ContinuousMap.sub_apply, Real.norm_eq_abs, hrep j ⟨x,hx⟩, r,
48
+ ContinuousMap.coe_mk] using hb
49
+ exact hb'.trans hj.le
50
+ · have hgx : g x=0 := image_eq_zero_of_notMem_tsupport (fun h => hx (hg h))
51
+ have hfx : f j x=0 := image_eq_zero_of_notMem_tsupport (fun h => hx (hf j h))
52
+ simpa only [hgx,hfx,sub_self,abs_zero] using hε.le
53
+
54
+ omit [SecondCountableTopology X] in
55
+ /-- One nonnegative compactly supported cutoff dominates one on a given
56
+ compact set. -/
57
+ theorem exists_compact_test_cutoff (K : Set X) (hK : IsCompact K) :
58
+ ∃ f : C_c(X, ℝ), (∀ x, 0 ≤ f x) ∧ ∀ x ∈ K, 1 ≤ f x := by
59
+ obtain ⟨f,hf,hfc,_,h01⟩ := exists_continuousMap_one_of_isCompact_subset_isOpen
60
+ hK isOpen_univ (subset_univ K)
61
+ refine ⟨⟨f,hfc⟩,fun x => (h01 x).1,fun x hx => ?_⟩
62
+ change 1 ≤ f x
63
+ rw [hf hx]
64
+ rfl
65
+
66
+ /-- The determining family required by Radon reconstruction exists
67
+ without an additional density or cutoff hypothesis. -/
68
+ theorem exists_localTestFamily : Nonempty (LocalTestFamily X) := by
69
+ classical
70
+ let K := CompactExhaustion.choice X
71
+ have hdense (n : ℕ) := exists_compact_test_sequence (K n) (K.isCompact n)
72
+ choose f hf hfdense using hdense
73
+ have hcut (n : ℕ) := exists_compact_test_cutoff (K n) (K.isCompact n)
74
+ choose ψ hψ0 hψ1 using hcut
75
+ let test (j : ℕ) : C_c(X, ℝ) :=
76
+ match Encodable.decode (α := ℕ ⊕ (ℕ × ℕ)) j with
77
+ | some (.inl n) => ψ n
78
+ | some (.inr (n,k)) => f n k
79
+ | none => 0
80
+ have htest_cut (n : ℕ) : test (Encodable.encode (Sum.inl n : ℕ ⊕ (ℕ × ℕ)))=ψ n := by
81
+ simp only [test, Encodable.encodek]
82
+ have htest_dense (n j : ℕ) :
83
+ test (Encodable.encode (Sum.inr (n,j) : ℕ ⊕ (ℕ × ℕ)))=f n j := by
84
+ simp only [test, Encodable.encodek]
85
+ refine ⟨{
86
+ compactSet := K
87
+ isCompact := K.isCompact
88
+ exhaustive := fun _ h => K.exists_superset_of_isCompact h
89
+ test := test
90
+ cutoffIndex := fun n => Encodable.encode (Sum.inl n : ℕ ⊕ (ℕ × ℕ))
91
+ cutoff_nonneg := ?_
92
+ cutoff_one_le := ?_
93
+ dense := ?_ }⟩
94
+ · intro n x
95
+ rw [htest_cut]
96
+ exact hψ0 n x
97
+ · intro n x hx
98
+ rw [htest_cut]
99
+ exact hψ1 n x hx
100
+ · intro n g hg ε hε
101
+ obtain ⟨j,hj⟩ := hfdense n g hg ε hε
102
+ refine ⟨Encodable.encode (Sum.inr (n,j) : ℕ ⊕ (ℕ × ℕ)), ?_, ?_⟩
103
+ · rw [htest_dense]
104
+ exact hf n j
105
+ · rw [htest_dense]
106
+ exact hj
107
+
108
+ /-- A chosen countable family can be used for all times and all random
109
+ outcomes of a measure-valued construction. -/
110
+ def localTestFamily (X : Type*) [TopologicalSpace X] [T2Space X] [LocallyCompactSpace X]
111
+ [SecondCountableTopology X] : LocalTestFamily X :=
112
+ Classical.choice exists_localTestFamily
113
+
114
+ end SLEExactGauge
115
+
116
+ end
117
+
118
+ end OAI
lean/OAI/Probability/SLE/Mass/RadonTestLimit.lean ADDED
@@ -0,0 +1,138 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import Mathlib.MeasureTheory.Integral.RieszMarkovKakutani.Real
2
+ import Mathlib.Topology.MetricSpace.Sequences
3
+
4
+ namespace OAI
5
+
6
+ /-! Deterministic reconstruction in `mass:construction`. A countable
7
+ family locally dense in compactly supported continuous functions,
8
+ including nonnegative exhaustion cutoffs, determines one Radon limit. -/
9
+
10
+ noncomputable section
11
+ open Set Filter MeasureTheory
12
+ open scoped Topology CompactlySupported
13
+
14
+ namespace SLEExactGauge
15
+
16
+ variable {X : Type*} [TopologicalSpace X] [T2Space X] [LocallyCompactSpace X]
17
+ [MeasurableSpace X] [BorelSpace X]
18
+
19
+ /-- A countable determining family with explicit support control.
20
+ Density is in the uniform norm within each compact exhaustion set. -/
21
+ structure LocalTestFamily (X : Type*) [TopologicalSpace X] where
22
+ compactSet : ℕ → Set X
23
+ isCompact : ∀ n, IsCompact (compactSet n)
24
+ exhaustive : ∀ K : Set X, IsCompact K → ∃ n, K ⊆ compactSet n
25
+ test : ℕ → C_c(X, ℝ)
26
+ cutoffIndex : ℕ → ℕ
27
+ cutoff_nonneg : ∀ n x, 0 ≤ test (cutoffIndex n) x
28
+ cutoff_one_le : ∀ n x, x ∈ compactSet n → 1 ≤ test (cutoffIndex n) x
29
+ dense : ∀ n (f : C_c(X, ℝ)), tsupport f ⊆ compactSet n →
30
+ ∀ ε : ℝ, 0 < ε → ∃ j, tsupport (test j) ⊆ compactSet n ∧
31
+ ∀ x, |f x-test j x| ≤ ε
32
+
33
+ omit [T2Space X] [LocallyCompactSpace X] [MeasurableSpace X] [BorelSpace X] in
34
+ lemma LocalTestFamily.weighted_approximation (D : LocalTestFamily X) (f : C_c(X, ℝ)) :
35
+ ∃ k, (∀ x, 0 ≤ D.test k x) ∧ ∀ ε : ℝ, 0 < ε →
36
+ ∃ j, ∀ x, |f x-D.test j x| ≤ ε * D.test k x := by
37
+ obtain ⟨n,hn⟩ := D.exhaustive (tsupport f) f.hasCompactSupport
38
+ refine ⟨D.cutoffIndex n,D.cutoff_nonneg n,fun ε hε => ?_⟩
39
+ obtain ⟨j,hj,happrox⟩ := D.dense n f hn ε hε
40
+ refine ⟨j,fun x => ?_⟩
41
+ by_cases hx : x ∈ D.compactSet n
42
+ · exact (happrox x).trans (le_mul_of_one_le_right hε.le (D.cutoff_one_le n x hx))
43
+ · have hfx : f x=0 := image_eq_zero_of_notMem_tsupport (fun h => hx (hn h))
44
+ have hjx : D.test j x=0 := image_eq_zero_of_notMem_tsupport (fun h => hx (hj h))
45
+ rw [hfx,hjx,sub_self,abs_zero]
46
+ exact mul_nonneg hε.le (D.cutoff_nonneg n x)
47
+
48
+ omit [T2Space X] [LocallyCompactSpace X] in
49
+ lemma integral_sub_le_cutoff (μ : Measure X) [IsFiniteMeasureOnCompacts μ]
50
+ (f g ψ : C_c(X, ℝ)) (ε : ℝ)
51
+ (h : ∀ x, |f x-g x| ≤ ε*ψ x) :
52
+ |(∫ x, f x ∂μ)-(∫ x, g x ∂μ)| ≤ ε*(∫ x, ψ x ∂μ) := by
53
+ rw [← integral_sub f.integrable g.integrable]
54
+ have hh := norm_integral_le_of_norm_le (f := fun x => f x-g x) (ψ.integrable.const_mul ε)
55
+ (ae_of_all μ (fun x => by simpa only [Real.norm_eq_abs] using h x))
56
+ simpa only [Real.norm_eq_abs,integral_const_mul] using hh
57
+
58
+ omit [T2Space X] [LocallyCompactSpace X] in
59
+ /-- Compactly supported integrals are Cauchy once the countable tests
60
+ converge. Cutoff convergence supplies the uniform local mass bounds. -/
61
+ theorem LocalTestFamily.integrals_cauchy (D : LocalTestFamily X)
62
+ (μ : ℕ → Measure X) [∀ n, IsFiniteMeasureOnCompacts (μ n)]
63
+ (htest : ∀ j, ∃ a : ℝ, Tendsto (fun n => ∫ x, D.test j x ∂μ n) atTop (𝓝 a))
64
+ (f : C_c(X, ℝ)) : CauchySeq (fun n => ∫ x, f x ∂μ n) := by
65
+ obtain ⟨k,_,hk⟩ := D.weighted_approximation f
66
+ obtain ⟨a,ha⟩ := htest k
67
+ obtain ⟨B,hB⟩ := (Metric.isBounded_range_of_tendsto _ ha).exists_norm_le
68
+ have hB0 : 0 ≤ B := (norm_nonneg _).trans (hB _ (mem_range_self 0))
69
+ have hB' (n : ℕ) : (∫ x, D.test k x ∂μ n) ≤ B :=
70
+ (le_abs_self _).trans (by simpa only [Real.norm_eq_abs] using hB _ (mem_range_self n))
71
+ apply Metric.cauchySeq_iff.mpr
72
+ intro ε hε
73
+ let δ : ℝ := ε/(4*(B+1))
74
+ have hδ : 0 < δ := by dsimp [δ]; positivity
75
+ have hδB : δ*B < ε/4 := by
76
+ dsimp [δ]
77
+ rw [div_mul_eq_mul_div,div_lt_div_iff₀ (by positivity) (by norm_num : (0:ℝ)<4)]
78
+ nlinarith
79
+ obtain ⟨j,hj⟩ := hk δ hδ
80
+ obtain ⟨a,ha⟩ := htest j
81
+ obtain ⟨N,hN⟩ := Metric.cauchySeq_iff.mp ha.cauchySeq (ε/2) (by positivity)
82
+ have herror (n : ℕ) : dist (∫ x, f x ∂μ n) (∫ x, D.test j x ∂μ n) ≤ δ*B := by
83
+ rw [Real.dist_eq]
84
+ exact (integral_sub_le_cutoff (μ n) f (D.test j) (D.test k) δ hj).trans
85
+ (mul_le_mul_of_nonneg_left (hB' n) hδ.le)
86
+ refine ⟨N,fun n hn m hm => ?_⟩
87
+ have hmid := hN n hn m hm
88
+ have htri := dist_triangle (∫ x, f x ∂μ n) (∫ x, D.test j x ∂μ n) (∫ x, f x ∂μ m)
89
+ have htri' := dist_triangle (∫ x, D.test j x ∂μ n) (∫ x, D.test j x ∂μ m) (∫ x, f x ∂μ m)
90
+ have hright : dist (∫ x, D.test j x ∂μ m) (∫ x, f x ∂μ m) ≤ δ*B := by
91
+ rw [dist_comm]
92
+ exact herror m
93
+ have hleft := herror n
94
+ linarith
95
+
96
+ /-- Positive limits of compact continuous tests are represented by one
97
+ locally finite regular measure. -/
98
+ theorem radon_limit_of_all_test_limits (μ : ℕ → Measure X)
99
+ [∀ n, IsFiniteMeasureOnCompacts (μ n)]
100
+ (hlimit : ∀ f : C_c(X, ℝ), ∃ a : ℝ,
101
+ Tendsto (fun n => ∫ x, f x ∂μ n) atTop (𝓝 a)) :
102
+ ∃ ν : Measure X, ν.Regular ∧ IsFiniteMeasureOnCompacts ν ∧
103
+ ∀ f : C_c(X, ℝ), Tendsto (fun n => ∫ x, f x ∂μ n) atTop (𝓝 (∫ x, f x ∂ν)) := by
104
+ choose L hL using hlimit
105
+ let I (n : ℕ) : C_c(X, ℝ) →ₚ[ℝ] ℝ :=
106
+ CompactlySupportedContinuousMap.integralPositiveLinearMap (μ n)
107
+ have hI (f : C_c(X, ℝ)) : Tendsto (fun n => I n f) atTop (𝓝 (L f)) := hL f
108
+ have hadd (f g : C_c(X, ℝ)) : L (f+g) = L f+L g := by
109
+ apply tendsto_nhds_unique (hI (f+g))
110
+ simpa only [map_add] using (hI f).add (hI g)
111
+ have hsmul (c : ℝ) (f : C_c(X, ℝ)) : L (c • f) = c • L f := by
112
+ apply tendsto_nhds_unique (hI (c • f))
113
+ simpa only [map_smul] using tendsto_const_nhds.smul (hI f)
114
+ let Λ : C_c(X, ℝ) →ₚ[ℝ] ℝ :=
115
+ { toFun := L
116
+ map_add' := hadd
117
+ map_smul' := hsmul
118
+ monotone' := fun f g hfg => le_of_tendsto_of_tendsto' (hI f) (hI g)
119
+ (fun n => (I n).monotone hfg) }
120
+ refine ⟨RealRMK.rieszMeasure Λ,inferInstance,inferInstance,fun f => ?_⟩
121
+ rw [RealRMK.integral_rieszMeasure]
122
+ exact hL f
123
+
124
+ /-- Reconstruction from a single countable locally determining family. -/
125
+ theorem LocalTestFamily.exists_radon_limit (D : LocalTestFamily X)
126
+ (μ : ℕ → Measure X) [∀ n, IsFiniteMeasureOnCompacts (μ n)]
127
+ (htest : ∀ j, ∃ a : ℝ, Tendsto (fun n => ∫ x, D.test j x ∂μ n) atTop (𝓝 a)) :
128
+ ∃ ν : Measure X, ν.Regular ∧ IsFiniteMeasureOnCompacts ν ∧
129
+ ∀ f : C_c(X, ℝ), Tendsto (fun n => ∫ x, f x ∂μ n) atTop (𝓝 (∫ x, f x ∂ν)) := by
130
+ apply radon_limit_of_all_test_limits μ
131
+ intro f
132
+ exact cauchySeq_tendsto_of_complete (D.integrals_cauchy μ htest f)
133
+
134
+ end SLEExactGauge
135
+
136
+ end
137
+
138
+ end OAI
lean/OAI/Probability/SLE/Mass/RadonTestLimitProperties.lean ADDED
@@ -0,0 +1,101 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Mass.RadonTestFamily
2
+
3
+ namespace OAI
4
+
5
+ /-! Order and closed-support properties of the reconstructed Radon limits. -/
6
+
7
+ noncomputable section
8
+ open Set Filter MeasureTheory
9
+ open scoped Topology CompactlySupported ENNReal
10
+
11
+ namespace SLEExactGauge
12
+
13
+ variable {X : Type*} [TopologicalSpace X] [T2Space X] [LocallyCompactSpace X]
14
+ [MeasurableSpace X] [BorelSpace X]
15
+
16
+ lemma compact_measure_le_test_integral (μ : Measure X) [μ.Regular]
17
+ (f : C_c(X, ℝ)) (hf : ∀ x, 0 ≤ f x) {K : Set X} (hK : IsCompact K)
18
+ (hfone : ∀ x ∈ K, f x=1) : μ K ≤ ENNReal.ofReal (∫ x, f x ∂μ) := by
19
+ simpa only [RealRMK.rieszMeasure_integralPositiveLinearMap,
20
+ CompactlySupportedContinuousMap.integralPositiveLinearMap_apply] using
21
+ RealRMK.rieszMeasure_le_of_eq_one
22
+ (CompactlySupportedContinuousMap.integralPositiveLinearMap μ) hf hK hfone
23
+
24
+ lemma test_integral_le_measure (μ : Measure X) [μ.Regular]
25
+ (f : C_c(X, ℝ)) (hf : ∀ x, 0 ≤ f x ∧ f x ≤ 1) {U : Set X}
26
+ (hs : tsupport f ⊆ U) : ENNReal.ofReal (∫ x, f x ∂μ) ≤ μ U := by
27
+ simpa only [RealRMK.rieszMeasure_integralPositiveLinearMap,
28
+ CompactlySupportedContinuousMap.integralPositiveLinearMap_apply] using
29
+ RealRMK.le_rieszMeasure_tsupport_subset
30
+ (CompactlySupportedContinuousMap.integralPositiveLinearMap μ) hf hs
31
+
32
+ /-- The positive compact-test order determines the order of Radon measures. -/
33
+ theorem radon_measure_le_of_nonneg_tests (μ ν : Measure X) [μ.Regular] [ν.Regular]
34
+ (h : ∀ f : C_c(X, ℝ), (∀ x, 0 ≤ f x) → (∫ x, f x ∂μ) ≤ ∫ x, f x ∂ν) : μ ≤ ν := by
35
+ have hc (K : Set X) (hK : IsCompact K) : μ K ≤ ν K := by
36
+ apply ENNReal.le_of_forall_pos_le_add
37
+ intro ε hε _
38
+ obtain ⟨U,hKU,hU,hνU⟩ := K.exists_isOpen_le_add ν
39
+ (ne_of_gt (ENNReal.coe_lt_coe.mpr hε))
40
+ obtain ⟨f,hf1,hfc,hfs,hf01⟩ := exists_continuousMap_one_of_isCompact_subset_isOpen
41
+ hK hU hKU
42
+ let g : C_c(X, ℝ) := ⟨f,hfc⟩
43
+ have hg0 : ∀ x, 0 ≤ g x := fun x => (hf01 x).1
44
+ calc
45
+ μ K ≤ ENNReal.ofReal (∫ x, g x ∂μ) := compact_measure_le_test_integral μ g hg0 hK hf1
46
+ _ ≤ ENNReal.ofReal (∫ x, g x ∂ν) := ENNReal.ofReal_le_ofReal (h g hg0)
47
+ _ ≤ ν U := test_integral_le_measure ν g hf01 hfs
48
+ _ ≤ ν K+ε := hνU
49
+ have ho (U : Set X) (hU : IsOpen U) : μ U ≤ ν U := by
50
+ rw [Measure.Regular.innerRegular.measure_eq_iSup hU]
51
+ exact iSup_le fun K => iSup_le fun hKU => iSup_le fun hK => (hc K hK).trans (measure_mono hKU)
52
+ apply Measure.le_iff'.mpr
53
+ intro A
54
+ rw [A.measure_eq_iInf_isOpen ν]
55
+ exact le_iInf fun U => le_iInf fun hAU => le_iInf fun hU => (measure_mono hAU).trans (ho U hU)
56
+
57
+ /-- Order of positive approximants passes to every compact-test limit. -/
58
+ theorem radon_limits_mono (μ ν : ℕ → Measure X)
59
+ [∀ n, IsFiniteMeasureOnCompacts (μ n)] [∀ n, IsFiniteMeasureOnCompacts (ν n)]
60
+ (μ₀ ν₀ : Measure X) [μ₀.Regular] [ν₀.Regular]
61
+ (hμ : ∀ f : C_c(X, ℝ), Tendsto (fun n => ∫ x, f x ∂μ n) atTop (𝓝 (∫ x, f x ∂μ₀)))
62
+ (hν : ∀ f : C_c(X, ℝ), Tendsto (fun n => ∫ x, f x ∂ν n) atTop (𝓝 (∫ x, f x ∂ν₀)))
63
+ (hle : ∀ n, μ n ≤ ν n) : μ₀ ≤ ν₀ := by
64
+ apply radon_measure_le_of_nonneg_tests
65
+ intro f hf
66
+ exact le_of_tendsto_of_tendsto' (hμ f) (hν f) (fun n =>
67
+ integral_mono_measure (hle n) (ae_of_all _ hf) f.integrable)
68
+
69
+ /-- Vanishing compact tests inside an open set force the Radon mass of
70
+ that open set to vanish. -/
71
+ theorem radon_open_eq_zero_of_tests (μ : Measure X) [μ.Regular] (U : Set X) (hU : IsOpen U)
72
+ (hzero : ∀ f : C_c(X, ℝ), tsupport f ⊆ U → (∫ x, f x ∂μ)=0) : μ U=0 := by
73
+ apply le_antisymm ?_ bot_le
74
+ rw [Measure.Regular.innerRegular.measure_eq_iSup hU]
75
+ refine iSup_le fun K => iSup_le fun hKU => iSup_le fun hK => ?_
76
+ obtain ⟨f,hf1,hfc,hfs,hf01⟩ := exists_continuousMap_one_of_isCompact_subset_isOpen
77
+ hK hU hKU
78
+ let g : C_c(X, ℝ) := ⟨f,hfc⟩
79
+ have hg0 : ∀ x, 0 ≤ g x := fun x => (hf01 x).1
80
+ have hb := compact_measure_le_test_integral μ g hg0 hK hf1
81
+ change μ K ≤ 0
82
+ simpa only [hzero g hfs,ENNReal.ofReal_zero] using hb
83
+
84
+ /-- The compact-test limit is carried by a closed set if each compact
85
+ test separated from it eventually vanishes. -/
86
+ theorem radon_limit_carried_by_closed (μ : ℕ → Measure X) (ν : Measure X) [ν.Regular]
87
+ (hlim : ∀ f : C_c(X, ℝ), Tendsto (fun n => ∫ x, f x ∂μ n) atTop (𝓝 (∫ x, f x ∂ν)))
88
+ (S : Set X) (hS : IsClosed S)
89
+ (hvanish : ∀ f : C_c(X, ℝ), tsupport f ⊆ Sᶜ →
90
+ ∀ᶠ n in atTop, (∫ x, f x ∂μ n)=0) : ν Sᶜ=0 := by
91
+ apply radon_open_eq_zero_of_tests ν Sᶜ hS.isOpen_compl
92
+ intro f hf
93
+ have heq : (fun _ : ℕ => (0:ℝ)) =ᶠ[atTop] (fun n => ∫ x, f x ∂μ n) :=
94
+ (hvanish f hf).mono (fun _ h => h.symm)
95
+ exact tendsto_nhds_unique (hlim f) (tendsto_const_nhds.congr' heq)
96
+
97
+ end SLEExactGauge
98
+
99
+ end
100
+
101
+ end OAI
lean/OAI/Probability/SLE/Mass/RadonTestMeasurability.lean ADDED
@@ -0,0 +1,138 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import OAI.Probability.SLE.Mass.RadonTestLimitProperties
2
+ import Mathlib.MeasureTheory.Measure.GiryMonad
3
+ import Mathlib.MeasureTheory.Constructions.Polish.Basic
4
+
5
+ namespace OAI
6
+
7
+ /-! A Radon measure determined by measurable compact continuous tests is
8
+ a measurable measure-valued function. Local finite restrictions are used,
9
+ so no finite total-mass hypothesis is imposed. -/
10
+
11
+ noncomputable section
12
+ open Set Filter MeasureTheory
13
+ open scoped Topology CompactlySupported ENNReal
14
+
15
+ namespace SLEExactGauge
16
+
17
+ variable {X : Type*} [TopologicalSpace X] [T2Space X] [LocallyCompactSpace X]
18
+ [SecondCountableTopology X] [MeasurableSpace X] [BorelSpace X]
19
+
20
+ /-- A fixed countable list of compact cutoffs recovers the mass of a fixed
21
+ open set simultaneously for all Radon measures. -/
22
+ theorem exists_open_cutoff_sequence (U : Set X) (hU : IsOpen U) :
23
+ ∃ f : ℕ → C_c(X, ℝ), (∀ n x, 0 ≤ f n x ∧ f n x ≤ 1) ∧
24
+ (∀ n, tsupport (f n) ⊆ U) ∧ ∀ (μ : Measure X), μ.Regular →
25
+ μ U = ⨆ n, ENNReal.ofReal (∫ x, f n x ∂μ) := by
26
+ let : LocallyCompactSpace U := hU.locallyCompactSpace
27
+ let K := CompactExhaustion.choice U
28
+ let A (n : ℕ) : Set X := Subtype.val '' K n
29
+ have hAc (n : ℕ) : IsCompact (A n) := (K.isCompact n).image continuous_subtype_val
30
+ have hAU (n : ℕ) : A n ⊆ U := by rintro _ ⟨x,_,rfl⟩; exact x.2
31
+ have hcut (n : ℕ) := exists_continuousMap_one_of_isCompact_subset_isOpen (hAc n) hU (hAU n)
32
+ choose f hf1 hfc hfs hf01 using hcut
33
+ let g (n : ℕ) : C_c(X, ℝ) := ⟨f n,hfc n⟩
34
+ have hAm : Monotone A := fun _ _ h => image_mono (K.subset h)
35
+ have hUnion : (⋃ n, A n)=U := by
36
+ ext x
37
+ constructor
38
+ · intro hx
39
+ obtain ⟨n,hn⟩ := mem_iUnion.mp hx
40
+ exact hAU n hn
41
+ · intro hx
42
+ obtain ⟨n,hn⟩ := K.exists_mem (⟨x,hx⟩ : U)
43
+ exact mem_iUnion.mpr ⟨n,⟨⟨x,hx⟩,hn,rfl⟩⟩
44
+ refine ⟨g,hf01,hfs,fun μ hμ => ?_⟩
45
+ let : μ.Regular := hμ
46
+ apply le_antisymm
47
+ · rw [← hUnion,hAm.measure_iUnion]
48
+ exact iSup_mono fun n => compact_measure_le_test_integral μ (g n)
49
+ (fun x => (hf01 n x).1) (hAc n) (hf1 n)
50
+ · exact iSup_le fun n => test_integral_le_measure μ (g n) (hf01 n) (hfs n)
51
+
52
+ /-- Measurability of all compact continuous test integrals implies
53
+ measurability of every open-set evaluation. -/
54
+ theorem measurable_open_evaluation_of_tests
55
+ {Ω : Type*} [MeasurableSpace Ω] (ν : Ω → Measure X)
56
+ (hν : ∀ ω, (ν ω).Regular)
57
+ (htest : ∀ f : C_c(X, ℝ), Measurable (fun ω => ∫ x, f x ∂ν ω))
58
+ (U : Set X) (hU : IsOpen U) : Measurable (fun ω => ν ω U) := by
59
+ obtain ⟨f,_,_,hf⟩ := exists_open_cutoff_sequence U hU
60
+ have he : (fun ω => ν ω U)=(fun ω => ⨆ n, ENNReal.ofReal (∫ x, f n x ∂ν ω)) :=
61
+ funext fun ω => hf (ν ω) (hν ω)
62
+ rw [he]
63
+ exact Measurable.iSup fun n => (htest (f n)).ennreal_ofReal
64
+
65
+ omit [T2Space X] in
66
+ /-- Locally finite Radon kernels are measurable once all their open-set
67
+ evaluations are measurable. -/
68
+ theorem measurable_radon_of_open_evaluations
69
+ {Ω : Type*} [MeasurableSpace Ω] (ν : Ω → Measure X)
70
+ (hν : ∀ ω, (ν ω).Regular)
71
+ (hopen : ∀ U : Set X, IsOpen U → Measurable (fun ω => ν ω U)) : Measurable ν := by
72
+ let K := CompactExhaustion.choice X
73
+ let U (n : ℕ) := interior (K n)
74
+ have hU (n : ℕ) : IsOpen (U n) := isOpen_interior
75
+ have hfinite (n : ℕ) (ω : Ω) : ν ω (U n) < ⊤ := by
76
+ let : (ν ω).Regular := hν ω
77
+ exact (measure_mono interior_subset).trans_lt (K.isCompact n).measure_lt_top
78
+ have hlocal (n : ℕ) : ∀ A : Set X, MeasurableSet A →
79
+ Measurable (fun ω => ν ω (A ∩ U n)) := by
80
+ apply MeasurableSet.induction_on_open
81
+ · intro A hA
82
+ exact hopen _ (hA.inter (hU n))
83
+ · intro A hA hm
84
+ have he (ω : Ω) : ν ω (Aᶜ ∩ U n)=ν ω (U n)-ν ω (A ∩ U n) := by
85
+ have hset : Aᶜ ∩ U n=U n \ (A ∩ U n) := by ext x; simp only [Set.mem_inter_iff,Set.mem_compl_iff,Set.mem_sdiff]; tauto
86
+ rw [hset]
87
+ exact measure_sdiff inter_subset_right (hA.inter (hU n).measurableSet).nullMeasurableSet
88
+ ((measure_mono inter_subset_right).trans_lt (hfinite n ω)).ne
89
+ simp_rw [he]
90
+ exact (hopen _ (hU n)).sub hm
91
+ · intro A hd hA hm
92
+ have hd' : Pairwise (fun i j => Disjoint (A i ∩ U n) (A j ∩ U n)) :=
93
+ fun i j hij => (hd hij).mono inter_subset_left inter_subset_left
94
+ have he (ω : Ω) : ν ω ((⋃ i, A i) ∩ U n)=∑' i, ν ω (A i ∩ U n) := by
95
+ rw [iUnion_inter]
96
+ exact measure_iUnion hd' (fun i => (hA i).inter (hU n).measurableSet)
97
+ simp_rw [he]
98
+ exact Measurable.tsum hm
99
+ have hUnion : (⋃ n, U n)=univ := by
100
+ apply eq_univ_of_forall
101
+ intro x
102
+ obtain ⟨n,hn⟩ := K.exists_mem x
103
+ exact mem_iUnion.mpr ⟨n+1,K.subset_interior_succ n hn⟩
104
+ have hUm : Monotone U := fun _ _ h => interior_mono (K.subset h)
105
+ apply Measure.measurable_of_measurable_coe
106
+ intro A hA
107
+ have he (ω : Ω) : ν ω A=⨆ n, ν ω (A ∩ U n) := by
108
+ have hmono : Monotone (fun n => A ∩ U n) := monotone_const.inter hUm
109
+ rw [← hmono.measure_iUnion,← inter_iUnion,hUnion,inter_univ]
110
+ simp_rw [he]
111
+ exact Measurable.iSup fun n => hlocal n A hA
112
+
113
+ /-- A reconstruction with measurable compact-test integrals is a genuine
114
+ measurable measure-valued map, not only a collection of scalar tests. -/
115
+ theorem measurable_radon_of_tests
116
+ {Ω : Type*} [MeasurableSpace Ω] (ν : Ω → Measure X)
117
+ (hν : ∀ ω, (ν ω).Regular)
118
+ (htest : ∀ f : C_c(X, ℝ), Measurable (fun ω => ∫ x, f x ∂ν ω)) : Measurable ν :=
119
+ measurable_radon_of_open_evaluations ν hν (measurable_open_evaluation_of_tests ν hν htest)
120
+
121
+ /-- Pointwise convergence of measurable compact-test integrals provides
122
+ measurability of the reconstructed Radon kernel. -/
123
+ theorem measurable_radon_of_test_limits
124
+ {Ω : Type*} [MeasurableSpace Ω] (μ : ℕ → Ω → Measure X) (ν : Ω → Measure X)
125
+ (hν : ∀ ω, (ν ω).Regular)
126
+ (hmeas : ∀ n (f : C_c(X, ℝ)), Measurable (fun ω => ∫ x, f x ∂μ n ω))
127
+ (hlim : ∀ ω (f : C_c(X, ℝ)), Tendsto (fun n => ∫ x, f x ∂μ n ω)
128
+ atTop (𝓝 (∫ x, f x ∂ν ω))) : Measurable ν := by
129
+ apply measurable_radon_of_tests ν hν
130
+ intro f
131
+ exact measurable_of_tendsto_metrizable (fun n => hmeas n f)
132
+ (tendsto_pi_nhds.mpr (fun ω => hlim ω f))
133
+
134
+ end SLEExactGauge
135
+
136
+ end
137
+
138
+ end OAI