File size: 7,155 Bytes
dd14c26
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
import Mathlib
import OAI.Probability.LogConcave.Numerics.CenteringVelocityPicard

namespace OAI

section
noncomputable section
namespace LogConcaveSampling
open Set MeasureTheory ProbabilityTheory
open scoped Classical BigOperators NNReal

lemma productPointEquiv_lipschitz_one (d e : ℕ) :
    LipschitzWith 1 (productPointEquiv d e) := by
  apply LipschitzWith.of_dist_le_mul
  intro y z
  simp only [NNReal.coe_one,one_mul,dist_eq_norm,←map_sub]
  rw [Prod.norm_def]
  exact max_le (productPointEquiv_fst_norm_le _) (productPointEquiv_snd_norm_le _)

lemma productPointEquiv_symm_norm_le (d e : ℕ) (p : Point d × Point e) :
    ‖(productPointEquiv d e).symm p‖≤2*‖p‖ := by
  have h := productPointEquiv_norm_sq ((productPointEquiv d e).symm p)
  simp only [ContinuousLinearEquiv.apply_symm_apply] at h
  have h1 : ‖p.1‖≤‖p‖ := norm_fst_le p
  have h2 : ‖p.2‖≤‖p‖ := norm_snd_le p
  have h1' := pow_le_pow_left₀ (norm_nonneg p.1) h1 2
  have h2' := pow_le_pow_left₀ (norm_nonneg p.2) h2 2
  nlinarith [norm_nonneg p,norm_nonneg ((productPointEquiv d e).symm p)]

lemma productPointEquiv_symm_lipschitz_two (d e : ℕ) :
    LipschitzWith 2 (productPointEquiv d e).symm := by
  apply LipschitzWith.of_dist_le_mul
  intro y z
  simpa only [NNReal.coe_ofNat,dist_eq_norm,←map_sub] using
    productPointEquiv_symm_norm_le d e (y-z)

lemma centering_joint_product_law {d : ℕ} {F : Point d → ℝ} {lam : ℝ≥0}
    (hF : Primitive F lam) (x : Point d) {r T : ℝ}
    (hr : 0<r) (hl : (lam:ℝ)*r^2≤1/2) (hT0 : 0≤T) (hT1 : T<1) :
    (gibbs (centeringPotential F x r T)).map (productPointEquiv d d)=
      (interpolationLaw F x r T).prod (stdGaussian (Point d)) := by
  rw [centeringPotential,productPotential_gibbs
    (interpolationPotential_smooth hF x hr.le hl hT0 hT1).continuous
    (gaussianPotential_polySmooth d).smooth.continuous,gaussianPotential_gibbs]
  rw [interpolationLaw_eq_gibbs hF x hr.le (by linarith only [hl])
    (by nlinarith [probability_time hT0 hT1])]
end LogConcaveSampling

end

end

section

noncomputable section
namespace LogConcaveSampling
open Set MeasureTheory ProbabilityTheory Quadrature TensorEnergy RMSIntegral
open scoped Classical BigOperators NNReal

def centeringVelocityJoint {d : ℕ} (F : Point d → ℝ) (x : Point d)
    (r T h ψ s : ℝ) (n m N : ℕ) (e : ProbabilityNode T h (n+1))
    (y : Point (d+d)) : Point (d+d) :=
  (productPointEquiv d d).symm
    (centeringVelocityPicard F x r T h ψ s n m N e (productPointEquiv d d y))

lemma actual_centering_joint_field {d : ℕ} {F : Point d → ℝ} {lam : ℝ≥0}
    (hF : Primitive F lam) (x : Point d) {r T : ℝ} (hr : 0<r) (hlam : 0<lam)
    (hl : (lam:ℝ)*r^2≤1/2) (hT0 : 0≤T) (hT1 : T<1) (s : ℝ) (y : Point (d+d)) :
    productPointEquiv d d (skewLieField (centeringPotential F x r T)
      (jointSkew (centeringKernel hF x hr hl hT0 hT1) s) y)=
    skewCenteringField (centeringKernel hF x hr hl hT0 hT1)
      (fun z => conditionalFieldMean F x r T z-primitiveExpectedField F x r) s
      (productPointEquiv d d y) := by
  apply jointSkew_field ((interpolationPotential_smooth hF x hr.le hl hT0 hT1).differentiable (by simp))
  · intro i j
    exact (contDiff_const.inner ℝ
      ((centeringKernel_smooth hF x hr hlam hl hT0 hT1).clm_apply contDiff_const)).differentiable (by simp)
  · exact centeringKernel_strong hF x hr hlam hl hT0 hT1

lemma centeringVelocityJoint_error_sq {d : ℕ} {F : Point d → ℝ} {lam : ℝ≥0}
    (hF : Primitive F lam) (x : Point d) {r T h ψ s : ℝ} (hr : 0<r) (hlam : 0<lam)
    (hl : (lam:ℝ)*r^2≤1/2) (hT0 : 0≤T) (hT1 : T<1)
    (n m N : ℕ) (e : ProbabilityNode T h (n+1)) (y : Point (d+d)) :
    ‖centeringVelocityJoint F x r T h ψ s n m N e y-
      skewLieField (centeringPotential F x r T)
        (jointSkew (centeringKernel hF x hr hl hT0 hT1) s) y‖^2=
    (r*s)⁻¹^2 * ‖kernelQuadraturePicard F x r T h ψ (n+1) m N e
        (terminalQuadratureWeight T h n) (productPointEquiv d d y)-
        r • (centeringKernel hF x hr hl hT0 hT1 (productPointEquiv d d y).1).adjoint
          (productPointEquiv d d y).2‖^2 := by
  rw [productPointEquiv_norm_sq,map_sub,actual_centering_joint_field hF x hr hlam hl hT0 hT1]
  simp only [centeringVelocityJoint,ContinuousLinearEquiv.apply_symm_apply,
    centeringVelocityPicard,skewCenteringField,Prod.fst_sub,Prod.snd_sub,sub_self,norm_zero]
  have hscale : -(r*s)⁻¹*r= -s⁻¹ := by field_simp
  rw [←hscale,←smul_smul,←smul_sub,norm_smul,mul_pow]
  simp only [Real.norm_eq_abs,sq_abs,neg_sq]
  ring

lemma centeringVelocityJoint_rms_of_kernel {d : ℕ} {F : Point d → ℝ} {lam : ℝ≥0}
    (hF : Primitive F lam) (x : Point d) {r T h ψ s : ℝ} (hr : 0<r) (hlam : 0<lam)
    (hl : (lam:ℝ)*r^2≤1/2) (hT0 : 0≤T) (hT1 : T<1)
    (n m N : ℕ) (e : ProbabilityNode T h (n+1)) {B : ℝ}
    (hK : Continuous (kernelQuadraturePicard F x r T h ψ (n+1) m N e (terminalQuadratureWeight T h n)))
    (hi : Integrable (fun p => ‖kernelQuadraturePicard F x r T h ψ (n+1) m N e
      (terminalQuadratureWeight T h n) p-r •
      (centeringKernel hF x hr hl hT0 hT1 p.1).adjoint p.2‖^2)
      ((interpolationLaw F x r T).prod (stdGaussian (Point d))))
    (hb : (∫p,‖kernelQuadraturePicard F x r T h ψ (n+1) m N e (terminalQuadratureWeight T h n) p-
      r • (centeringKernel hF x hr hl hT0 hT1 p.1).adjoint p.2‖^2
      ∂((interpolationLaw F x r T).prod (stdGaussian (Point d))))≤B) :
    let err := fun y => centeringVelocityJoint F x r T h ψ s n m N e y-
      skewLieField (centeringPotential F x r T) (jointSkew (centeringKernel hF x hr hl hT0 hT1) s) y
    Integrable (fun y => ‖err y‖^2) (gibbs (centeringPotential F x r T)) ∧
      (∫y,‖err y‖^2 ∂gibbs (centeringPotential F x r T))≤(r*s)⁻¹^2*B := by
  intro err
  let f := fun p : Point d × Point d => ‖kernelQuadraturePicard F x r T h ψ (n+1) m N e
      (terminalQuadratureWeight T h n) p-r •(centeringKernel hF x hr hl hT0 hT1 p.1).adjoint p.2‖^2
  have hc : Continuous f := by
    apply Continuous.pow
    apply Continuous.norm
    apply hK.sub
    exact (continuous_const_smul r).comp
      ((ContinuousLinearMap.adjoint.continuous.comp
        ((centeringKernel_smooth hF x hr hlam hl hT0 hT1).continuous.comp continuous_fst)).clm_apply continuous_snd)
  have he := centering_joint_product_law hF x hr hl hT0 hT1
  have hp : Integrable (fun y => f (productPointEquiv d d y)) (gibbs (centeringPotential F x r T)) := by
    apply (integrable_map_measure hc.measurable.aestronglyMeasurable
      (productPointEquiv d d).continuous.measurable.aemeasurable).mp
    rw [he]
    exact hi
  have hb' : (∫y,f (productPointEquiv d d y) ∂gibbs (centeringPotential F x r T))≤B := by
    rw [←integral_map (productPointEquiv d d).continuous.measurable.aemeasurable hc.measurable.aestronglyMeasurable,he]
    exact hb
  dsimp only [err]
  simp_rw [centeringVelocityJoint_error_sq hF x hr hlam hl hT0 hT1]
  refine ⟨hp.const_mul _,?_⟩
  rw [integral_const_mul]
  exact mul_le_mul_of_nonneg_left hb' (sq_nonneg _)
end LogConcaveSampling

end

end

end OAI