openAI-math-dataset / lean /OAI /Geometry /SmoothYau /Smoothness /ContDiffSmoothFiniteWave.lean
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import Mathlib
import OAI.Geometry.SmoothYau.Estimates.CanonicalCutoffWave
import OAI.Geometry.SmoothYau.Geometry.WaveDerivCompLinear
import OAI.Geometry.SmoothYau.Limits.FrameDualNorm
import OAI.Geometry.SmoothYau.Smoothness.FlowInitialFderiv
namespace OAI
noncomputable section
namespace YauCounterexamples
section
open Set Filter
open scoped Topology ContDiff
open Set Filter
open scoped Topology ContDiff
open MvPolynomial
open Set Filter
open scoped ContDiff
open Set Filter
open scoped Topology ContDiff
open Set Filter MvPolynomial
open scoped Topology ContDiff
open Set Filter Function MvPolynomial
open scoped Topology ContDiff
open Set Filter Function MvPolynomial
open scoped Topology ContDiff
open Set Filter
open scoped Topology ContDiff
open Set Filter
open scoped Topology ContDiff
open Set Filter Function
open scoped Topology ContDiff
open Set Filter Function
open scoped Topology ContDiff
open scoped Topology
open Set Filter Manifold Bundle MeasureTheory
open scoped Topology ContDiff ENNReal
open Matrix
open scoped Topology Matrix.Norms.Elementwise
open Set Filter Manifold Bundle
open scoped Topology ContDiff
open Set
open scoped Topology ContDiff NNReal
variable {E : Type*} [NormedAddCommGroup E] [InnerProductSpace ℝ E]
[FiniteDimensional ℝ E]
local instance normalFamilyVecNorm : NormedAddCommGroup (E →L[ℝ] E) := inferInstance
local instance normalFamilyVecSpace : NormedSpace ℝ (E →L[ℝ] E) := inferInstance
local instance normalFamilyBiVecNorm : NormedAddCommGroup (E →L[ℝ] E →L[ℝ] E) := inferInstance
local instance normalFamilyBiVecSpace : NormedSpace ℝ (E →L[ℝ] E →L[ℝ] E) := inferInstance
local instance normalFamilyDualNorm : NormedAddCommGroup (E →L[ℝ] ℝ) := inferInstance
local instance normalFamilyDualSpace : NormedSpace ℝ (E →L[ℝ] ℝ) := inferInstance
local instance normalFamilyFormNorm : NormedAddCommGroup (E →L[ℝ] E →L[ℝ] ℝ) := inferInstance
local instance normalFamilyFormSpace : NormedSpace ℝ (E →L[ℝ] E →L[ℝ] ℝ) := inferInstance
lemma contDiff_frameChristoffel (g : SmoothMetric E E) :
ContDiff ℝ ∞ (fun q : E × (E →L[ℝ] E) =>
(metricChristoffel g q.1).bilinearComp q.2 q.2) := by
have h1 : ContDiff ℝ ∞ (fun q : E × (E →L[ℝ] E) => (metricChristoffel g q.1).comp q.2) :=
((contDiff_metricChristoffel g).comp contDiff_fst).clm_comp contDiff_snd
have h2 := (ContinuousLinearMap.flipₗᵢ ℝ E E E).toContinuousLinearMap.contDiff.comp h1
have h3 := h2.clm_comp contDiff_snd
exact (ContinuousLinearMap.flipₗᵢ ℝ E E E).toContinuousLinearMap.contDiff.comp h3
lemma contDiff_normalJetFamily (g : SmoothMetric E E) :
ContDiff ℝ ∞ (fun q : (E × (E →L[ℝ] E)) × E =>
normalJetMap q.1.1 q.1.2 ((metricChristoffel g q.1.1).bilinearComp q.1.2 q.1.2) q.2) := by
have hC : ContDiff ℝ ∞ (fun q : (E × (E →L[ℝ] E)) × E => (metricChristoffel g q.1.1).bilinearComp q.1.2 q.1.2) :=
(contDiff_frameChristoffel g).comp contDiff_fst
exact (contDiff_fst.fst.add (contDiff_fst.snd.clm_apply contDiff_snd)).sub
((hC.clm_apply contDiff_snd |>.clm_apply contDiff_snd).const_smul (1/2 : ℝ))
lemma contDiff_normalMetricFamily_apply (g : SmoothMetric E E) (v w : E) :
ContDiff ℝ ∞ (fun q : (E × (E →L[ℝ] E)) × E =>
normalMetricTensor g q.1.1 q.1.2 q.2 v w) := by
have hC : ContDiff ℝ ∞ (fun q : (E × (E →L[ℝ] E)) × E =>
((metricChristoffel g q.1.1).bilinearComp q.1.2 q.1.2) q.2) :=
((contDiff_frameChristoffel g).comp contDiff_fst).clm_apply contDiff_snd
have hD := (show ContDiff ℝ ∞ (fun q : (E × (E →L[ℝ] E)) × E => q.1.2) from contDiff_fst.snd).sub hC
exact (((contDiff_selfMetricFlat g).comp (contDiff_normalJetFamily g)).clm_apply
(hD.clm_apply contDiff_const)).clm_apply (hD.clm_apply contDiff_const)
theorem compact_normal_coordinate_radius [Nontrivial E] (g : SmoothMetric E E)
{K : Set E} (hK : IsCompact K) :
∃ r : ℝ≥0, 0 < r ∧ ∀ q ∈ metricFrameSet g K,
∃ e : OpenPartialHomeomorph E E,
(e : E → E) = normalJetMap q.1 q.2
((metricChristoffel g q.1).bilinearComp q.2 q.2) ∧
e.source = Metric.ball 0 r ∧ ContDiffOn ℝ ∞ e.symm e.target := by
obtain ⟨R,hR,hRb⟩ := metricFrameSet_inverse_bound g hK
obtain ⟨B,hBb⟩ := (metricFrameSet_isCompact g hK).exists_bound_of_continuousOn
(f := fun q : E × (E →L[ℝ] E) =>
(metricChristoffel g q.1).bilinearComp q.2 q.2)
(contDiff_frameChristoffel g).continuous.continuousOn
let r : ℝ≥0 := ⟨(2*(R+1)*(max B 0+1))⁻¹, by positivity⟩
have hr : 0 < r := by change 0 < (2*(R+1)*(max B 0+1))⁻¹; positivity
refine ⟨r,hr,?_⟩
intro q hq
obtain ⟨A,hA⟩ := metricFrameSet_equiv g hq
let C := (metricChristoffel g q.1).bilinearComp q.2 q.2
have hAi : (A.symm : E →L[ℝ] E) = q.2.inverse := by
rw [←hA, ContinuousLinearMap.inverse_equiv]
have hAiPos : 0 < ‖(A.symm : E →L[ℝ] E)‖₊ := by
rw [nnnorm_pos]
intro hz
obtain ⟨v,hv⟩ := exists_ne (0 : E)
have hh := congrArg (fun T : E →L[ℝ] E => T (A v)) hz
simp only [ContinuousLinearEquiv.coe_coe, A.symm_apply_apply, _root_.zero_apply] at hh
exact hv hh
have hb : ‖(A.symm : E →L[ℝ] E)‖ * (‖C‖ * (r : ℝ)) < 1 := by
have hi : ‖(A.symm : E →L[ℝ] E)‖ ≤ R := by rw [hAi]; exact hRb q hq
have hc : ‖C‖ ≤ max B 0 := (hBb q hq).trans (le_max_left _ _)
have hm : ‖(A.symm : E →L[ℝ] E)‖ * (‖C‖ * (r : ℝ)) ≤
R * (max B 0 * (2*(R+1)*(max B 0+1))⁻¹) := by
change ‖(A.symm : E →L[ℝ] E)‖ * (‖C‖ * (2*(R+1)*(max B 0+1))⁻¹) ≤ _
gcongr
apply lt_of_le_of_lt hm
rw [←mul_assoc, ←div_eq_mul_inv, div_lt_one (by positivity)]
nlinarith [le_max_right B 0]
have hsmall : ‖C‖₊ * r < ‖(A.symm : E →L[ℝ] E)‖₊⁻¹ := by
have hnn : ‖(A.symm : E →L[ℝ] E)‖₊ * (‖C‖₊ * r) < 1 := by exact_mod_cast hb
simpa only [mul_one] using (lt_inv_mul_iff₀ hAiPos).mpr hnn
obtain ⟨e,he,hs,hi⟩ := normalJetMap_uniform_inverse q.1 A C
(fun v w => metricChristoffel_symm g q.1 (q.2 v) (q.2 w)) r hsmall
exact ⟨e, by simpa only [hA] using he, hs, hi⟩
end
section
open Set Filter
open scoped Topology ContDiff
open Set Filter
open scoped Topology ContDiff
open MvPolynomial
open Set Filter
open scoped ContDiff
open Set Filter
open scoped Topology ContDiff
open Set Filter MvPolynomial
open scoped Topology ContDiff
open Set Filter Function MvPolynomial
open scoped Topology ContDiff
open Set Filter Function MvPolynomial
open scoped Topology ContDiff
open Set Filter
open scoped Topology ContDiff
open Set Filter
open scoped Topology ContDiff
open Set Filter Function
open scoped Topology ContDiff
open Set Filter Function
open scoped Topology ContDiff
open scoped Topology
open Set Filter Manifold Bundle MeasureTheory
open scoped Topology ContDiff ENNReal
open Matrix
open scoped Topology Matrix.Norms.Elementwise
open Set Filter Manifold Bundle
open scoped Topology ContDiff
open Set Filter
open scoped Topology ContDiff
variable {P E F G : Type*} [NormedAddCommGroup P] [NormedSpace ℝ P]
[NormedAddCommGroup E] [NormedSpace ℝ E] [NormedAddCommGroup F] [NormedSpace ℝ F]
[NormedAddCommGroup G] [NormedSpace ℝ G]
lemma normal_iteratedFDeriv_comp_clm_at (L : F →L[ℝ] E) {f : E → G} {x : F} (n : ℕ)
(hf : ContDiffAt ℝ n f (L x)) :
iteratedFDeriv ℝ n (f ∘ L) x =
(iteratedFDeriv ℝ n f (L x)).compContinuousLinearMap (fun _ => L) := by
obtain ⟨U,hU,hu⟩ := hf.contDiffOn le_rfl (by simp)
obtain ⟨V,hVU,hVo,hx⟩ := mem_nhds_iff.mp hU
have he := L.iteratedFDerivWithin_comp_right (hu.mono hVU) hVo.uniqueDiffOn
(hVo.preimage L.continuous).uniqueDiffOn hx (le_refl (n : WithTop ℕ∞))
rw [iteratedFDerivWithin_of_isOpen n hVo hx,
iteratedFDerivWithin_of_isOpen n (hVo.preimage L.continuous) hx] at he
exact he
lemma parameter_iteratedFDeriv (f : P × E → F) (t : P) (x : E) (n : ℕ)
(hf : ContDiffAt ℝ n f (t,x)) :
iteratedFDeriv ℝ n (fun y => f (t,y)) x =
(iteratedFDeriv ℝ n f (t,x)).compContinuousLinearMap
(fun _ => ContinuousLinearMap.inr ℝ P E) := by
let L := ContinuousLinearMap.inr ℝ P E
let q : P × E → F := fun z => f ((t,0)+z)
have hq : ContDiffAt ℝ n q (L x) := by
have hg : ContDiffAt ℝ n (fun z : P × E => (t,0)+z) (L x) := by fun_prop
exact (show ContDiffAt ℝ n f ((t,0)+L x) by simpa [L] using hf).comp (L x) hg
have hj := normal_iteratedFDeriv_comp_clm_at L n hq
simpa [q,L,Function.comp_def,iteratedFDeriv_comp_add_left] using hj
lemma continuousAt_parameter_iteratedFDeriv (f : P × E → F) {z : P × E} (n : ℕ)
(hf : ContDiffAt ℝ ∞ f z) :
ContinuousAt (fun w : P × E => iteratedFDeriv ℝ n (fun y => f (w.1,y)) w.2) z := by
have hc := (ContinuousMultilinearMap.continuous_precomp
(fun _ : Fin n => ContinuousLinearMap.inr ℝ P E)).continuousAt.comp
(hf.continuousAt_iteratedFDeriv (k := n) (ENat.natCast_le_of_coe_top_le_withTop le_rfl n))
apply hc.congr_of_eventuallyEq
filter_upwards [(hf.of_le (show (n : WithTop ℕ∞) ≤ (∞ : WithTop ℕ∞) from ENat.natCast_le_of_coe_top_le_withTop le_rfl n)).eventually (by simp)] with w hw
exact parameter_iteratedFDeriv f w.1 w.2 n hw
end
section
open Set Filter
open scoped Topology ContDiff
open Set Filter
open scoped Topology ContDiff
open MvPolynomial
open Set Filter
open scoped ContDiff
open Set Filter
open scoped Topology ContDiff
open Set Filter MvPolynomial
open scoped Topology ContDiff
open Set Filter Function MvPolynomial
open scoped Topology ContDiff
open Set Filter Function MvPolynomial
open scoped Topology ContDiff
open Set Filter
open scoped Topology ContDiff
open Set Filter
open scoped Topology ContDiff
open Set Filter Function
open scoped Topology ContDiff
open Set Filter Function
open scoped Topology ContDiff
open scoped Topology
open Set Filter Manifold Bundle MeasureTheory
open scoped Topology ContDiff ENNReal
open Matrix
open scoped Topology Matrix.Norms.Elementwise
open Set Filter Manifold Bundle
open scoped Topology ContDiff
open Set Filter
open scoped Topology ContDiff
section ParameterDerivative
variable {P E F : Type*} [NormedAddCommGroup P] [NormedSpace ℝ P]
[NormedAddCommGroup E] [NormedSpace ℝ E] [NormedAddCommGroup F] [NormedSpace ℝ F]
lemma parameter_fderiv_apply (f : P × E → F) (hf : Differentiable ℝ f)
(p : P) (x v : E) :
fderiv ℝ (fun y => f (p,y)) x v = fderiv ℝ f (p,x) (0,v) := by
have h := (hf (p,x)).hasFDerivAt.comp x
((hasFDerivAt_const p x).prodMk (hasFDerivAt_id x))
exact congrArg (fun T => T v) h.fderiv
lemma contDiff_parameter_fderiv_apply (f : P × E → F) (hf : ContDiff ℝ ∞ f) (v : E) :
ContDiff ℝ ∞ (fun q : P × E => fderiv ℝ (fun x => f (q.1,x)) q.2 v) := by
simp only [parameter_fderiv_apply f (hf.differentiable (by simp))]
exact (hf.fderiv_right (by simp)).clm_apply contDiff_const
lemma continuous_parameter_iteratedFDeriv (f : P × E → F) (hf : ContDiff ℝ ∞ f) (k : ℕ) :
Continuous (fun q : P × E => iteratedFDeriv ℝ k (fun x => f (q.1,x)) q.2) :=
continuous_iff_continuousAt.mpr (fun _ => continuousAt_parameter_iteratedFDeriv f k hf.contDiffAt)
end ParameterDerivative
variable {P ι : Type*} [NormedAddCommGroup P] [NormedSpace ℝ P]
[Fintype ι] [DecidableEq ι]
lemma contDiff_matrix_det (A : P → Matrix ι ι ℝ)
(hA : ∀ i j, ContDiff ℝ ∞ (fun p => A p i j)) :
ContDiff ℝ ∞ (fun p => (A p).det) := by
simp only [Matrix.det_apply']
apply ContDiff.sum
intro σ _
apply contDiff_const.mul
apply contDiff_prod
intro i _
exact hA _ _
lemma contDiff_matrix_adjugate (A : P → Matrix ι ι ℝ)
(hA : ∀ i j, ContDiff ℝ ∞ (fun p => A p i j)) (i j : ι) :
ContDiff ℝ ∞ (fun p => (A p).adjugate i j) := by
simp only [Matrix.adjugate_apply, Matrix.det_apply']
apply ContDiff.sum
intro σ _
apply contDiff_const.mul
apply contDiff_prod
intro k _
simp only [Matrix.updateRow_apply]
split_ifs
· exact contDiff_const
· exact hA _ _
lemma contDiffOn_matrix_inv (A : P → Matrix ι ι ℝ)
(hA : ∀ i j, ContDiff ℝ ∞ (fun p => A p i j)) (i j : ι) :
ContDiffOn ℝ ∞ (fun p => (A p)⁻¹ i j) {p | (A p).det ≠ 0} := by
simp only [Matrix.inv_def, Ring.inverse_eq_inv, Matrix.smul_apply, smul_eq_mul]
exact ((contDiff_matrix_det A hA).contDiffOn.inv (fun _ hp => hp)).mul
(contDiff_matrix_adjugate A hA i j).contDiffOn
end
section
open Set Filter
open scoped Topology ContDiff
open Set Filter
open scoped Topology ContDiff
open MvPolynomial
open Set Filter
open scoped ContDiff
open Set Filter
open scoped Topology ContDiff
open Set Filter MvPolynomial
open scoped Topology ContDiff
open Set Filter Function MvPolynomial
open scoped Topology ContDiff
open Set Filter Function MvPolynomial
open scoped Topology ContDiff
open Set Filter
open scoped Topology ContDiff
open Set Filter
open scoped Topology ContDiff
open Set Filter Function
open scoped Topology ContDiff
open Set Filter Function
open scoped Topology ContDiff
open scoped Topology
open Set Filter Manifold Bundle MeasureTheory
open scoped Topology ContDiff ENNReal
open Matrix
open scoped Topology Matrix.Norms.Elementwise
open Set Filter Manifold Bundle
open scoped Topology ContDiff
open Set Filter Matrix
open scoped Topology ContDiff Matrix Matrix.Norms.Elementwise
abbrev NormalWaveSpace := EuclideanSpace ℝ (Fin 3)
abbrev NormalWaveParameter := NormalWaveSpace × (NormalWaveSpace →L[ℝ] NormalWaveSpace)
def normalWaveMetric (g : SmoothMetric NormalWaveSpace NormalWaveSpace)
(q : NormalWaveParameter) (x : NormalWaveSpace) : Matrix (Fin 3) (Fin 3) ℝ :=
fun i j => normalMetricTensor g q.1 q.2 x
(EuclideanSpace.basisFun (Fin 3) ℝ i) (EuclideanSpace.basisFun (Fin 3) ℝ j)
lemma contDiff_normalWaveMetric (g : SmoothMetric NormalWaveSpace NormalWaveSpace) (i j : Fin 3) :
ContDiff ℝ ∞ (fun q : NormalWaveParameter × NormalWaveSpace => normalWaveMetric g q.1 q.2 i j) :=
contDiff_normalMetricFamily_apply g _ _
lemma normalWaveMetric_zero (g : SmoothMetric NormalWaveSpace NormalWaveSpace)
{K : Set NormalWaveSpace} {q : NormalWaveParameter} (hq : q ∈ metricFrameSet g K) :
normalWaveMetric g q 0 = 1 := by
ext i j
change normalMetricTensor g q.1 q.2 0 _ _ = _
rw [normalMetricTensor_at_zero]
change selfMetricFlat g q.1 (q.2 _) (q.2 _) = _
rw [hq.2]
exact (EuclideanSpace.basisFun (Fin 3) ℝ).inner_eq_ite i j
lemma normalWaveMetric_first_jet (g : SmoothMetric NormalWaveSpace NormalWaveSpace)
(q : NormalWaveParameter) : HasFDerivAt (𝕜 := ℝ) (normalWaveMetric g q) 0 0 := by
have hc (i j : Fin 3) : HasFDerivAt (𝕜 := ℝ) (fun x => normalWaveMetric g q x i j) 0 0 := by
have h := (contDiff_normalMetricTensor_apply g q.1 q.2
(EuclideanSpace.basisFun (Fin 3) ℝ i) (EuclideanSpace.basisFun (Fin 3) ℝ j)).differentiable (by simp) 0
simpa only [normalWaveMetric, normalMetricTensor_normal_jet] using h.hasFDerivAt
convert (hasFDerivAt_pi.mpr (fun i => hasFDerivAt_pi.mpr (fun j => hc i j))) using 1 <;> rfl
lemma hasFDerivAt_matrix_inv_zero {ι : Type*} [Fintype ι] [DecidableEq ι]
{E : Type*} [NormedAddCommGroup E] [NormedSpace ℝ E]
(A : E → Matrix ι ι ℝ) {x : E} (hA : HasFDerivAt (𝕜 := ℝ) A 0 x) (hdet : (A x).det ≠ 0) :
HasFDerivAt (𝕜 := ℝ) (fun y => (A y)⁻¹) 0 x := by
have hc (i j : ι) : ContDiffAt ℝ ∞ (fun M : Matrix ι ι ℝ => M⁻¹ i j) (A x) := by
have hO : IsOpen {M : Matrix ι ι ℝ | M.det ≠ 0} :=
isOpen_ne_fun (contDiff_matrix_det id (fun _ _ => by fun_prop)).continuous continuous_const
exact (contDiffOn_matrix_inv id (fun _ _ => by fun_prop) i j _ hdet).contDiffAt
(hO.mem_nhds hdet)
have hi : DifferentiableAt ℝ (fun M : Matrix ι ι ℝ => M⁻¹) (A x) := by
apply differentiableAt_pi.mpr
intro i
apply differentiableAt_pi.mpr
intro j
exact (hc i j).differentiableAt (by simp)
have h := hi.hasFDerivAt.comp x hA
erw [ContinuousLinearMap.comp_zero] at h
exact h
lemma normalWaveInverse_first_jet (g : SmoothMetric NormalWaveSpace NormalWaveSpace)
{K : Set NormalWaveSpace} {q : NormalWaveParameter} (hq : q ∈ metricFrameSet g K) :
HasFDerivAt (𝕜 := ℝ) (fun x => (normalWaveMetric g q x)⁻¹) 0 0 :=
hasFDerivAt_matrix_inv_zero _ (normalWaveMetric_first_jet g q) (by rw [normalWaveMetric_zero g hq]; simp)
theorem exists_normal_inverse_extension (g : SmoothMetric NormalWaveSpace NormalWaveSpace)
{K : Set NormalWaveSpace} (hK : IsCompact K) :
∃ A : NormalWaveParameter × NormalWaveSpace → Matrix (Fin 3) (Fin 3) ℝ,
∃ d : NormalWaveParameter × NormalWaveSpace → ℝ,
ContDiff ℝ ∞ A ∧ ContDiff ℝ ∞ d ∧
∃ O : Set (NormalWaveParameter × NormalWaveSpace), IsOpen O ∧
metricFrameSet g K ×ˢ {(0 : NormalWaveSpace)} ⊆ O ∧
∀ q ∈ O, A q = (normalWaveMetric g q.1 q.2)⁻¹ ∧
d q = (normalWaveMetric g q.1 q.2).det⁻¹ := by
let G := fun q : NormalWaveParameter × NormalWaveSpace => normalWaveMetric g q.1 q.2
let V := {q | (G q).det ≠ 0}
have hG (i j : Fin 3) : ContDiff ℝ ∞ (fun q => G q i j) := contDiff_normalWaveMetric g i j
have hV : IsOpen V := isOpen_ne_fun (contDiff_matrix_det G hG).continuous continuous_const
have hc : IsCompact (metricFrameSet g K ×ˢ {(0 : NormalWaveSpace)}) :=
(metricFrameSet_isCompact g hK).prod isCompact_singleton
have hsub : metricFrameSet g K ×ˢ {(0 : NormalWaveSpace)} ⊆ V := by
rintro ⟨q,x⟩ ⟨hq,hx⟩
have hx0 : x = 0 := mem_singleton_iff.mp hx
subst x
change (normalWaveMetric g q 0).det ≠ 0
rw [normalWaveMetric_zero g hq]
simp
have hF : ContDiffOn ℝ ∞ (fun q => ((G q)⁻¹,(G q).det⁻¹)) V := by
apply ContDiffOn.prodMk
· apply contDiffOn_pi.mpr
intro i
apply contDiffOn_pi.mpr
intro j
exact contDiffOn_matrix_inv G hG i j
· exact (contDiff_matrix_det G hG).contDiffOn.inv (fun _ h => h)
obtain ⟨ψ,hψ,he⟩ := smooth_extension_near_compact hc hV hsub hF
obtain ⟨O,hO,hKO,hEq⟩ := mem_nhdsSet_iff_exists.mp he
refine ⟨fun q => (ψ q).1,fun q => (ψ q).2,hψ.fst,hψ.snd,O,hO,hKO,?_⟩
intro q hq
have hh := hEq hq
exact ⟨(congrArg Prod.fst hh).symm,(congrArg Prod.snd hh).symm⟩
def normalWaveFirstCoefficient (g : SmoothMetric NormalWaveSpace NormalWaveSpace)
(q : NormalWaveParameter) (x : NormalWaveSpace) (j : Fin 3) : ℝ :=
∑ i, (fderiv ℝ (fun y => (normalWaveMetric g q y)⁻¹ i j) x
(EuclideanSpace.basisFun (Fin 3) ℝ i) +
(1/2 : ℝ) * (normalWaveMetric g q x)⁻¹ i j * (normalWaveMetric g q x).det⁻¹ *
fderiv ℝ (fun y => (normalWaveMetric g q y).det) x
(EuclideanSpace.basisFun (Fin 3) ℝ i))
lemma normalWaveMetric_det_first_jet (g : SmoothMetric NormalWaveSpace NormalWaveSpace)
(q : NormalWaveParameter) : HasFDerivAt (𝕜 := ℝ)
(fun x => (normalWaveMetric g q x).det) 0 0 := by
have hd := (contDiff_matrix_det (id : Matrix (Fin 3) (Fin 3) ℝ → _) (fun _ _ => by fun_prop)).differentiable (by simp)
have h := (hd (normalWaveMetric g q 0)).hasFDerivAt.comp 0
(normalWaveMetric_first_jet g q)
erw [ContinuousLinearMap.comp_zero] at h
exact h
lemma normalWaveFirstCoefficient_zero (g : SmoothMetric NormalWaveSpace NormalWaveSpace)
{K : Set NormalWaveSpace} {q : NormalWaveParameter} (hq : q ∈ metricFrameSet g K) :
normalWaveFirstCoefficient g q 0 = 0 := by
let : ContinuousSMul ℝ NormalWaveSpace := IsBoundedSMul.continuousSMul
funext j
have hi := normalWaveInverse_first_jet g hq
have hc (i j : Fin 3) : fderiv ℝ (fun y => (normalWaveMetric g q y)⁻¹ i j) 0 = 0 := by
have h1 := (ContinuousLinearMap.proj i : Matrix (Fin 3) (Fin 3) ℝ →L[ℝ] (Fin 3 → ℝ)).hasFDerivAt.comp 0 hi
have h2 := (ContinuousLinearMap.proj j : (Fin 3 → ℝ) →L[ℝ] ℝ).hasFDerivAt.comp 0 h1
have h := h2.fderiv
erw [ContinuousLinearMap.comp_zero] at h
exact h
simp [normalWaveFirstCoefficient,hc,(normalWaveMetric_det_first_jet g q).fderiv]
theorem exists_normal_wave_coefficients (g : SmoothMetric NormalWaveSpace NormalWaveSpace)
{K : Set NormalWaveSpace} (hK : IsCompact K) :
∃ A : NormalWaveParameter × NormalWaveSpace → Matrix (Fin 3) (Fin 3) ℝ,
∃ b : NormalWaveParameter × NormalWaveSpace → Fin 3 → ℝ,
ContDiff ℝ ∞ A ∧ ContDiff ℝ ∞ b ∧
∃ r > 0, ∀ q ∈ metricFrameSet g K,
A (q,0) = 1 ∧ HasFDerivAt (𝕜 := ℝ) (fun x => A (q,x)) 0 0 ∧ b (q,0) = 0 ∧
∀ x ∈ Metric.ball (0 : NormalWaveSpace) r,
A (q,x) = (normalWaveMetric g q x)⁻¹ ∧ b (q,x) = normalWaveFirstCoefficient g q x := by
obtain ⟨A,d,hA,hd,O,hO,hsub,he⟩ := exists_normal_inverse_extension g hK
let b := fun q : NormalWaveParameter × NormalWaveSpace => fun j : Fin 3 =>
∑ i, (fderiv ℝ (fun x => A (q.1,x) i j) q.2 (EuclideanSpace.basisFun (Fin 3) ℝ i) +
(1/2 : ℝ) * A q i j * d q * fderiv ℝ (fun x => (normalWaveMetric g q.1 x).det) q.2
(EuclideanSpace.basisFun (Fin 3) ℝ i))
have hb : ContDiff ℝ ∞ b := by
apply contDiff_pi.mpr
intro j
dsimp only [b]
apply ContDiff.sum
intro i _
apply ContDiff.add
· exact contDiff_parameter_fderiv_apply (fun q => A q i j) (contDiff_pi.mp (contDiff_pi.mp hA i) j) _
· exact ((contDiff_const.mul (contDiff_pi.mp (contDiff_pi.mp hA i) j)).mul hd).mul
(contDiff_parameter_fderiv_apply _
(contDiff_matrix_det _ (contDiff_normalWaveMetric g)) _)
have hgerm (q : NormalWaveParameter) (x : NormalWaveSpace) (hx : (q,x) ∈ O) :
(fun y => A (q,y)) =ᶠ[𝓝 x] (fun y => (normalWaveMetric g q y)⁻¹) := by
have ht : Tendsto (fun y : NormalWaveSpace => (q,y)) (𝓝 x) (𝓝 (q,x)) :=
(continuous_const.prodMk continuous_id).continuousAt
filter_upwards [ht (hO.mem_nhds hx)] with y hy
exact (he (q,y) hy).1
have hbe (q : NormalWaveParameter) (x : NormalWaveSpace) (hx : (q,x) ∈ O) :
b (q,x) = normalWaveFirstCoefficient g q x := by
funext j
dsimp only [b,normalWaveFirstCoefficient]
apply Finset.sum_congr rfl
intro i _
have hg : (fun y => A (q,y) i j) =ᶠ[𝓝 x] (fun y => (normalWaveMetric g q y)⁻¹ i j) :=
(hgerm q x hx).fun_comp (fun M => M i j)
rw [hg.fderiv_eq,(he (q,x) hx).1,(he (q,x) hx).2]
obtain ⟨U,V,hU,hV,hKU,h0V,hUV⟩ := generalized_tube_lemma (metricFrameSet_isCompact g hK)
isCompact_singleton hO hsub
obtain ⟨r,hr,hrV⟩ := Metric.isOpen_iff.mp hV 0 (h0V (mem_singleton 0))
refine ⟨A,b,hA,hb,r,hr,?_⟩
intro q hq
have hq0 : (q,0) ∈ O := hsub ⟨hq,mem_singleton 0⟩
refine ⟨?_,?_,?_,?_⟩
· rw [(he (q,0) hq0).1,normalWaveMetric_zero g hq]; simp
· exact (normalWaveInverse_first_jet g hq).congr_of_eventuallyEq (hgerm q 0 hq0)
· rw [hbe q 0 hq0,normalWaveFirstCoefficient_zero g hq]
· intro x hx
have hqx : (q,x) ∈ O := hUV ⟨hKU hq,hrV hx⟩
exact ⟨(he (q,x) hqx).1,hbe q x hqx⟩
end
section
open Set Filter
open scoped Topology ContDiff
open Set Filter
open scoped Topology ContDiff
open MvPolynomial
open Set Filter
open scoped ContDiff
open Set Filter
open scoped Topology ContDiff
open Set Filter MvPolynomial
open scoped Topology ContDiff
open Set Filter Function MvPolynomial
open scoped Topology ContDiff
open Set Filter Function MvPolynomial
open scoped Topology ContDiff
open Set Filter
open scoped Topology ContDiff
open Set Filter
open scoped Topology ContDiff
open Set Filter Function
open scoped Topology ContDiff
open Set Filter Function
open scoped Topology ContDiff
open scoped Topology
open Set Filter Manifold Bundle MeasureTheory
open scoped Topology ContDiff ENNReal
open Matrix
open scoped Topology Matrix.Norms.Elementwise
open Set Filter Manifold Bundle
open scoped Topology ContDiff
open Set Filter Matrix
open scoped Topology ContDiff Matrix.Norms.Elementwise
section Density
variable {E : Type*} [NormedAddCommGroup E] [NormedSpace ℝ E]
lemma density_first_derivative {d a : E → ℝ} {x : E}
(hd : DifferentiableAt ℝ d x) (ha : DifferentiableAt ℝ a x)
(hx : 0 < d x) (v : E) :
(Real.sqrt (d x))⁻¹ * fderiv ℝ (fun y => Real.sqrt (d y) * a y) x v =
fderiv ℝ a x v + (1/2 : ℝ) * a x * (d x)⁻¹ * fderiv ℝ d x v := by
erw [fderiv_fun_mul (hd.sqrt hx.ne') ha, _root_.add_apply]
simp only [_root_.smul_apply, smul_eq_mul, fderiv_sqrt hd hx.ne']
have hs : Real.sqrt (d x) ≠ 0 := (Real.sqrt_pos.mpr hx).ne'
have hs2 : Real.sqrt (d x) ^ 2 = d x := Real.sq_sqrt hx.le
field_simp
rw [hs2]
ring
end Density
lemma normalWaveDensity_firstCoefficient (g : SmoothMetric NormalWaveSpace NormalWaveSpace)
(q : NormalWaveParameter) {x : NormalWaveSpace}
(hx : 0 < (normalWaveMetric g q x).det) (j : Fin 3) :
(Real.sqrt (normalWaveMetric g q x).det)⁻¹ *
∑ i, fderiv ℝ (fun y => Real.sqrt (normalWaveMetric g q y).det *
(normalWaveMetric g q y)⁻¹ i j) x (EuclideanSpace.basisFun (Fin 3) ℝ i) =
normalWaveFirstCoefficient g q x j := by
rw [Finset.mul_sum]
apply Finset.sum_congr rfl
intro i hi
have hG (i j : Fin 3) : ContDiff ℝ ∞ (fun y => normalWaveMetric g q y i j) :=
(contDiff_normalMetricTensor_apply g q.1 q.2
(EuclideanSpace.basisFun (Fin 3) ℝ i) (EuclideanSpace.basisFun (Fin 3) ℝ j))
have hd := (contDiff_matrix_det _ hG).differentiable (by simp) x
have hO : IsOpen {y : NormalWaveSpace | (normalWaveMetric g q y).det ≠ 0} :=
isOpen_ne_fun (contDiff_matrix_det _ hG).continuous continuous_const
have ha := (contDiffOn_matrix_inv (normalWaveMetric g q) hG i j x hx.ne').contDiffAt
(hO.mem_nhds hx.ne')
exact density_first_derivative hd (ha.differentiableAt (by simp)) hx _
lemma compact_family_positive_radius {P E : Type*} [TopologicalSpace P]
[NormedAddCommGroup E] {K : Set P} (hK : IsCompact K)
(f : P × E → ℝ) (hf : Continuous f) (hpos : ∀ p ∈ K, 0 < f (p,0)) :
∃ r > 0, ∀ p ∈ K, ∀ x ∈ Metric.ball (0 : E) r, 0 < f (p,x) := by
let O : Set (P × E) := {q | 0 < f q}
have hO : IsOpen O := isOpen_lt continuous_const hf
have hsub : K ×ˢ {(0 : E)} ⊆ O := by
rintro ⟨p,x⟩ ⟨hp,hx⟩
change 0 < f (p,x)
have hx0 : x = 0 := hx
rw [hx0]
exact hpos p hp
obtain ⟨U,V,hU,hV,hKU,h0V,hUV⟩ := generalized_tube_lemma hK
isCompact_singleton hO hsub
obtain ⟨r,hr,hrV⟩ := Metric.isOpen_iff.mp hV 0 (h0V (mem_singleton 0))
exact ⟨r,hr,fun p hp x hx => hUV ⟨hKU hp,hrV hx⟩⟩
lemma compact_normal_density_radius (g : SmoothMetric NormalWaveSpace NormalWaveSpace)
{K : Set NormalWaveSpace} (hK : IsCompact K) :
∃ r > 0, ∀ q ∈ metricFrameSet g K, ∀ x ∈ Metric.ball (0 : NormalWaveSpace) r,
0 < (normalWaveMetric g q x).det := by
apply compact_family_positive_radius (metricFrameSet_isCompact g hK)
(fun q : NormalWaveParameter × NormalWaveSpace => (normalWaveMetric g q.1 q.2).det)
(contDiff_matrix_det _ (contDiff_normalWaveMetric g)).continuous
intro q hq
rw [normalWaveMetric_zero g hq]
simp
end
section
open Set Filter
open scoped Topology ContDiff
open Set Filter
open scoped Topology ContDiff
open MvPolynomial
open Set Filter
open scoped ContDiff
open Set Filter
open scoped Topology ContDiff
open Set Filter MvPolynomial
open scoped Topology ContDiff
open Set Filter Function MvPolynomial
open scoped Topology ContDiff
open Set Filter Function MvPolynomial
open scoped Topology ContDiff
open Set Filter
open scoped Topology ContDiff
open Set Filter
open scoped Topology ContDiff
open Set Filter Function
open scoped Topology ContDiff
open Set Filter Function
open scoped Topology ContDiff
open scoped Topology
open Set Filter Manifold Bundle MeasureTheory
open scoped Topology ContDiff ENNReal
open Matrix
open scoped Topology Matrix.Norms.Elementwise
open Set Filter Manifold Bundle
open scoped Topology ContDiff
open Set Filter Matrix
open scoped Topology ContDiff Matrix.Norms.Elementwise
abbrev normalWaveEquiv : (Fin 3 → ℝ) ≃L[ℝ] NormalWaveSpace :=
(PiLp.continuousLinearEquiv 2 ℝ (fun _ : Fin 3 => ℝ)).symm
lemma normalWaveEquiv_single (i : Fin 3) :
normalWaveEquiv (Pi.single i 1) = EuclideanSpace.basisFun (Fin 3) ℝ i := by
rw [EuclideanSpace.basisFun_apply]
rfl
theorem exists_normal_wave_pi_coefficients (g : SmoothMetric NormalWaveSpace NormalWaveSpace)
{K : Set NormalWaveSpace} (hK : IsCompact K) :
∃ A : NormalWaveParameter × (Fin 3 → ℝ) → Matrix (Fin 3) (Fin 3) ℂ,
∃ b : NormalWaveParameter × (Fin 3 → ℝ) → Fin 3 → ℂ,
ContDiff ℝ ∞ A ∧ ContDiff ℝ ∞ b ∧
∃ r > 0, ∀ q ∈ metricFrameSet g K,
(∀ i j, A (q,0) i j = if i = j then 1 else 0) ∧
(∀ i j, fderiv ℝ (fun x => A (q,x) i j) 0 = 0) ∧
b (q,0) = 0 ∧
∀ x, ‖normalWaveEquiv x‖ < r →
(∀ i j, A (q,x) i j = ((normalWaveMetric g q (normalWaveEquiv x))⁻¹ i j : ℂ)) ∧
(∀ j, b (q,x) j = (normalWaveFirstCoefficient g q (normalWaveEquiv x) j : ℂ)) := by
obtain ⟨A,b,hA,hb,r,hr,he⟩ := exists_normal_wave_coefficients g hK
let Ap := fun q : NormalWaveParameter × (Fin 3 → ℝ) =>
fun i j : Fin 3 => (A (q.1,normalWaveEquiv q.2) i j : ℂ)
let bp := fun q : NormalWaveParameter × (Fin 3 → ℝ) =>
fun j : Fin 3 => (b (q.1,normalWaveEquiv q.2) j : ℂ)
have hT : ContDiff ℝ ∞ (fun q : NormalWaveParameter × (Fin 3 → ℝ) => (q.1,normalWaveEquiv q.2)) :=
contDiff_fst.prodMk (normalWaveEquiv.contDiff.comp contDiff_snd)
have hAp : ContDiff ℝ ∞ Ap := by
apply contDiff_pi.mpr
intro i
apply contDiff_pi.mpr
intro j
exact Complex.ofRealCLM.contDiff.comp ((contDiff_pi.mp (contDiff_pi.mp hA i) j).comp hT)
have hbp : ContDiff ℝ ∞ bp := by
apply contDiff_pi.mpr
intro j
exact Complex.ofRealCLM.contDiff.comp ((contDiff_pi.mp hb j).comp hT)
refine ⟨Ap,bp,hAp,hbp,r,hr,?_⟩
intro q hq
obtain ⟨h0,hd,hb0,heq⟩ := he q hq
refine ⟨?_,?_,?_,?_⟩
· intro i j
simp only [Ap,map_zero,h0,Matrix.one_apply]
split_ifs <;> simp
· intro i j
let L : Matrix (Fin 3) (Fin 3) ℝ →L[ℝ] ℂ :=
Complex.ofRealCLM.comp ((ContinuousLinearMap.proj j : (Fin 3 → ℝ) →L[ℝ] ℝ).comp
(ContinuousLinearMap.proj i : Matrix (Fin 3) (Fin 3) ℝ →L[ℝ] (Fin 3 → ℝ)))
have hf := (L.hasFDerivAt.comp 0 hd).comp 0 normalWaveEquiv.hasFDerivAt
have hf' : HasFDerivAt (fun x => Ap (q,x) i j)
((L.comp 0).comp normalWaveEquiv.toContinuousLinearMap) 0 := hf
simpa only [ContinuousLinearMap.comp_zero,ContinuousLinearMap.zero_comp] using hf'.fderiv
· ext j
simp [bp,hb0]
· intro x hx
have h := heq (normalWaveEquiv x) (by simpa only [Metric.mem_ball,dist_zero_right] using hx)
exact ⟨fun i j => by dsimp [Ap]; rw [h.1],fun j => by dsimp [bp]; rw [h.2]⟩
lemma normal_profile_family_smooth (g : SmoothMetric NormalWaveSpace NormalWaveSpace)
(φ : NormalWaveSpace → ℝ) (hφ : ContDiff ℝ ∞ φ) :
ContDiff ℝ ∞ (fun q : NormalWaveParameter × NormalWaveSpace =>
φ (normalJetMap q.1.1 q.1.2 ((metricChristoffel g q.1.1).bilinearComp q.1.2 q.1.2) q.2)) :=
hφ.comp (contDiff_normalJetFamily g)
end
open Set Filter
open scoped Topology ContDiff
open Set Filter
open scoped Topology ContDiff
open MvPolynomial
open Set Filter
open scoped ContDiff
open Set Filter
open scoped Topology ContDiff
open Set Filter MvPolynomial
open scoped Topology ContDiff
open Set Filter Function MvPolynomial
open scoped Topology ContDiff
open Set Filter Function MvPolynomial
open scoped Topology ContDiff
open Set Filter
open scoped Topology ContDiff
open Set Filter
open scoped Topology ContDiff
open Set Filter Function
open scoped Topology ContDiff
open Set Filter Function
open scoped Topology ContDiff
open scoped Topology
open Set Filter Manifold Bundle MeasureTheory
open scoped Topology ContDiff ENNReal
open Matrix
open scoped Topology Matrix.Norms.Elementwise
open Set Filter Manifold Bundle
open scoped Topology ContDiff
open Set Filter
open scoped Topology ContDiff
lemma contDiff_smoothFiniteWave {E : Type*} [NormedAddCommGroup E] [NormedSpace ℝ E]
{S : E → ℂ} {V : ℕ → E → ℂ} (hS : ContDiff ℝ ∞ S)
(hV : ∀ j, ContDiff ℝ ∞ (V j)) (J : ℕ) (n : ℝ) :
ContDiff ℝ ∞ (smoothFiniteWave S V J n) := by
unfold smoothFiniteWave
exact (contDiff_const.mul hS).cexp.mul
(ContDiff.sum (fun j _ => contDiff_const.mul (hV j)))
lemma contDiff_canonicalCutoffWave
(A : Fin 3 → Fin 3 → (Fin 3 → ℝ) → ℂ) (b : Fin 3 → (Fin 3 → ℝ) → ℂ)
(s : ℂ) (z : Fin 3 → ℂ) (Q : ComplexPhaseMatrix)
(ζ : (Fin 3 → ℝ) → ℂ) (hζ : ContDiff ℝ ∞ ζ) (m D : ℕ) (n : ℝ) :
ContDiff ℝ ∞ (canonicalCutoffWave A b s z Q ζ m D n) :=
contDiff_smoothFiniteWave (contDiff_realPolyEval _)
(fun _ => hζ.mul (contDiff_realPolyEval _)) _ _
def normalWavePiOperator (g : SmoothMetric NormalWaveSpace NormalWaveSpace)
(q : NormalWaveParameter) (f : (Fin 3 → ℝ) → ℂ) (x : Fin 3 → ℝ) : ℂ :=
waveCoordinateOperator (EuclideanSpace.basisFun (Fin 3) ℝ)
(fun i j y => ((normalWaveMetric g q y)⁻¹ i j : ℂ))
(fun j y => (normalWaveFirstCoefficient g q y j : ℂ))
(f ∘ normalWaveEquiv.symm) (normalWaveEquiv x)
lemma normalWavePiOperator_eq (g : SmoothMetric NormalWaveSpace NormalWaveSpace)
(q : NormalWaveParameter) {f : (Fin 3 → ℝ) → ℂ} (hf : ContDiff ℝ ∞ f)
(x : Fin 3 → ℝ) :
normalWavePiOperator g q f x =
waveCoordinateOperator (fun i => Pi.single i 1)
(fun i j y => ((normalWaveMetric g q (normalWaveEquiv y))⁻¹ i j : ℂ))
(fun j y => (normalWaveFirstCoefficient g q (normalWaveEquiv y) j : ℂ)) f x := by
have h := waveCoordinateOperator_comp_linear normalWaveEquiv.toContinuousLinearMap
(fun i => Pi.single i 1)
(fun i j y => ((normalWaveMetric g q y)⁻¹ i j : ℂ))
(fun j y => (normalWaveFirstCoefficient g q y j : ℂ))
(hf.comp normalWaveEquiv.symm.contDiff) x
simpa only [normalWavePiOperator,Function.comp_def,ContinuousLinearEquiv.coe_coe,
normalWaveEquiv_single,ContinuousLinearEquiv.symm_apply_apply] using h.symm
lemma normalWavePiOperator_eq_extension (g : SmoothMetric NormalWaveSpace NormalWaveSpace)
(q : NormalWaveParameter) {f : (Fin 3 → ℝ) → ℂ} (hf : ContDiff ℝ ∞ f)
(A : Fin 3 → Fin 3 → (Fin 3 → ℝ) → ℂ) (b : Fin 3 → (Fin 3 → ℝ) → ℂ)
(x : Fin 3 → ℝ)
(hA : ∀ i j, A i j x = ((normalWaveMetric g q (normalWaveEquiv x))⁻¹ i j : ℂ))
(hb : ∀ j, b j x = (normalWaveFirstCoefficient g q (normalWaveEquiv x) j : ℂ)) :
normalWavePiOperator g q f x = waveCoordinateOperator (fun i => Pi.single i 1) A b f x := by
rw [normalWavePiOperator_eq g q hf]
simp only [waveCoordinateOperator,hA,hb]
end YauCounterexamples
end
end OAI