roseking's picture
Add lean source and binary files (part 69)
59d1c80 verified
Raw History Blame Contribute Delete
9.47 kB
import OAI.Geometry.IsometricImmersion.Metrics.UniversalMetricP
import OAI.Geometry.IsometricImmersion.Calculus.NormedCoordinateCalculus
namespace OAI
noncomputable section
open Set Filter Function
open scoped ContDiff Topology BigOperators Matrix Matrix.Norms.Elementwise
namespace SmoothLocal.HighEquation
open SmoothLocal.Geometry
section FiniteProducts
variable {E F G : Type*} [NormedAddCommGroup E] [NormedSpace ℝ E]
[NormedAddCommGroup F] [NormedSpace ℝ F] [NormedAddCommGroup G] [NormedSpace ℝ G]
theorem norm_iteratedFDeriv_pi_le {ι : Type*} [Fintype ι]
{f : E → ι → F} {p : E} (hf : ContDiffAt ℝ ∞ f p)
(n : ℕ) {M : ℝ} (hM : 0 ≤ M)
(hb : ∀ i, ‖iteratedFDeriv ℝ n (fun x => f x i) p‖ ≤ M) :
‖iteratedFDeriv ℝ n f p‖ ≤ M := by
have heq : iteratedFDeriv ℝ n f p =
ContinuousMultilinearMap.pi (fun i => iteratedFDeriv ℝ n (fun x => f x i) p) := by
ext v i
have hh := congrArg (fun L => L v)
((ContinuousLinearMap.proj i : (ι → F) →L[ℝ] F).iteratedFDeriv_comp_left
hf (WithTop.coe_le_coe.mpr le_top) (i := n))
exact hh.symm
rw [heq, ContinuousMultilinearMap.opNorm_pi]
exact (pi_norm_le_iff_of_nonneg hM).mpr hb
theorem norm_iteratedFDeriv_prod_le {f : E → F} {g : E → G} {p : E}
(hf : ContDiffAt ℝ ∞ f p) (hg : ContDiffAt ℝ ∞ g p)
(n : ℕ) {M : ℝ}
(hfB : ‖iteratedFDeriv ℝ n f p‖ ≤ M)
(hgB : ‖iteratedFDeriv ℝ n g p‖ ≤ M) :
‖iteratedFDeriv ℝ n (fun x => (f x, g x)) p‖ ≤ M := by
rw [iteratedFDeriv_prodMk hf hg (WithTop.coe_le_coe.mpr le_top),
ContinuousMultilinearMap.opNorm_prod]
exact max_le hfB hgB
theorem norm_iteratedFDeriv_comp_contraction
(L : E →L[ℝ] F) {f : F → G} {U : Set F}
(hf : ContDiffOn ℝ ∞ f U) (hU : IsOpen U) (hL : ‖L‖ ≤ 1)
{p : E} (hp : L p ∈ U) (n : ℕ) :
‖iteratedFDeriv ℝ n (f ∘ L) p‖ ≤ ‖iteratedFDeriv ℝ n f (L p)‖ := by
have hpre : IsOpen (L ⁻¹' U) := hU.preimage L.continuous
rw [← iteratedFDerivWithin_of_isOpen n hpre hp,
L.iteratedFDerivWithin_comp_right hf hU.uniqueDiffOn hpre.uniqueDiffOn hp
(WithTop.coe_le_coe.mpr le_top),
iteratedFDerivWithin_of_isOpen n hU hp]
exact ((iteratedFDeriv ℝ n f (L p)).norm_compContinuousLinearMap_le
(fun _ => L)).trans (by
calc
_ ≤ ‖iteratedFDeriv ℝ n f (L p)‖ * ∏ _ : Fin n, (1 : ℝ) :=
mul_le_mul_of_nonneg_left (Finset.prod_le_prod₀ (fun _ _ => norm_nonneg L)
(fun _ _ => hL)) (norm_nonneg _)
_ = _ := by simp)
theorem norm_iteratedFDeriv_id_pos (p : E) {n : ℕ} (hn : 1 ≤ n) :
‖iteratedFDeriv ℝ n (fun x : E => x) p‖ ≤ 1 := by
cases n with
| zero => omega
| succ n =>
rw [← norm_iteratedFDeriv_fderiv]
have he : fderiv ℝ (fun x : E => x) = (fun _ : E => ContinuousLinearMap.id ℝ E) := by
funext x
exact fderiv_fun_id
rw [he]
cases n with
| zero => simpa using (ContinuousLinearMap.norm_id_le (𝕜 := ℝ) (E := E))
| succ n => simp only [iteratedFDeriv_succ_const]; norm_num
end FiniteProducts
theorem norm_iteratedFDeriv_coordPartial_le {f : Coord → ℝ} {U : Set Coord}
(hf : ContDiffOn ℝ ∞ f U) (hU : IsOpen U) {p : Coord} (hp : p ∈ U)
(i : Fin 2) (n : ℕ) :
‖iteratedFDeriv ℝ n (coordPartial i f) p‖ ≤
‖iteratedFDeriv ℝ (n + 1) f p‖ := by
have hd : ContDiffAt ℝ ∞ (fderiv ℝ f) p :=
(hf.fderiv_of_isOpen hU (by simp)).contDiffAt (hU.mem_nhds hp)
have hh := norm_iteratedFDeriv_clm_apply_const (c := Pi.single i (1 : ℝ))
hd (n := n) (WithTop.coe_le_coe.mpr le_top)
have he : (fun y : Coord => fderiv ℝ f y (Pi.single i (1 : ℝ))) = coordPartial i f := by
funext y
rfl
rw [he, Pi.norm_single, norm_one, one_mul, norm_iteratedFDeriv_fderiv] at hh
exact hh
def statePointCLM : DarbouxState →L[ℝ] Coord :=
ContinuousLinearMap.pi (fun i =>
if i = 0 then ContinuousLinearMap.proj 0 else ContinuousLinearMap.proj 1)
theorem statePointCLM_eq (w : DarbouxState) : statePointCLM w = statePoint w := by
ext i
fin_cases i <;> simp [statePointCLM, statePoint]
theorem statePointCLM_norm_le : ‖statePointCLM‖ ≤ 1 := by
apply ContinuousLinearMap.opNorm_le_bound _ zero_le_one
intro w
rw [one_mul, statePointCLM_eq]
apply (pi_norm_le_iff_of_nonneg (norm_nonneg w)).mpr
intro i
fin_cases i
· exact norm_le_pi_norm w 0
· exact norm_le_pi_norm w 1
theorem norm_iteratedFDeriv_comp_statePoint {f : Coord → ℝ} {U : Set Coord}
(hf : ContDiffOn ℝ ∞ f U) (hU : IsOpen U) {w : DarbouxState}
(hw : statePoint w ∈ U) (n : ℕ) :
‖iteratedFDeriv ℝ n (fun v => f (statePoint v)) w‖ ≤
‖iteratedFDeriv ℝ n f (statePoint w)‖ := by
have hp : statePointCLM w ∈ U := by
rw [statePointCLM_eq]
exact hw
have hnumerical : ‖iteratedFDeriv ℝ n (f ∘ statePointCLM) w‖ ≤
‖iteratedFDeriv ℝ n f (statePointCLM w)‖ :=
norm_iteratedFDeriv_comp_contraction statePointCLM hf hU statePointCLM_norm_le hp n
have he : (fun v => f (statePoint v)) = f ∘ statePointCLM := by
funext v
change f (statePoint v) = f (statePointCLM v)
rw [statePointCLM_eq]
rw [he, ← statePointCLM_eq w]
exact hnumerical
theorem metricPBundle_contDiffOn {g : MetricField} {U : Set Coord}
(hg : SmoothPositiveOn g U) (hU : IsOpen U) :
ContDiffOn ℝ ∞ (metricPBundle g) (stateBaseDomain U) := by
have h0 : ContDiffOn ℝ ∞ (fun w => g (statePoint w)) (stateBaseDomain U) := by
apply contDiffOn_pi.mpr
intro i
apply contDiffOn_pi.mpr
intro j
exact (hg.1 i j).comp statePoint_contDiff.contDiffOn (fun w hw => hw)
have h1 : ContDiffOn ℝ ∞
(fun w d i j => coordPartial d (fun p => g p i j) (statePoint w)) (stateBaseDomain U) := by
apply contDiffOn_pi.mpr
intro d
apply contDiffOn_pi.mpr
intro i
apply contDiffOn_pi.mpr
intro j
exact (partial_contDiffOn (hg.1 i j) hU d).comp statePoint_contDiff.contDiffOn (fun w hw => hw)
have h2 : ContDiffOn ℝ ∞
(fun w d e i j => coordPartial d (coordPartial e (fun p => g p i j)) (statePoint w))
(stateBaseDomain U) := by
apply contDiffOn_pi.mpr
intro d
apply contDiffOn_pi.mpr
intro e
apply contDiffOn_pi.mpr
intro i
apply contDiffOn_pi.mpr
intro j
exact (partial_contDiffOn (partial_contDiffOn (hg.1 i j) hU e) hU d).comp
statePoint_contDiff.contDiffOn (fun w hw => hw)
exact h0.prodMk (h1.prodMk (h2.prodMk contDiffOn_id))
theorem metricPBundle_positive_jet_bound {g : MetricField} {U : Set Coord}
(hg : SmoothPositiveOn g U) (hU : IsOpen U) {w : DarbouxState}
(hw : statePoint w ∈ U) {N : ℕ} {G : ℝ} (hG : 0 ≤ G)
(hgB : ∀ i j k, k ≤ N + 2 →
‖iteratedFDeriv ℝ k (fun p => g p i j) (statePoint w)‖ ≤ G)
{n : ℕ} (hn : 1 ≤ n) (hnN : n ≤ N) :
‖iteratedFDeriv ℝ n (metricPBundle g) w‖ ≤ max 1 G := by
have hB := (metricPBundle_contDiffOn hg hU).contDiffAt
((stateBaseDomain_isOpen hU).mem_nhds hw)
have h0 := hB.fst
have h1 := hB.snd.fst
have h2 := hB.snd.snd.fst
have hId := hB.snd.snd.snd
have hcon {f : Coord → ℝ} (hf : ContDiffOn ℝ ∞ f U) :
‖iteratedFDeriv ℝ n (fun v => f (statePoint v)) w‖ ≤
‖iteratedFDeriv ℝ n f (statePoint w)‖ := by
exact norm_iteratedFDeriv_comp_statePoint hf hU hw n
have hb0 : ‖iteratedFDeriv ℝ n (fun v => g (statePoint v)) w‖ ≤ G := by
apply norm_iteratedFDeriv_pi_le h0 n hG
intro i
apply norm_iteratedFDeriv_pi_le ((contDiffAt_pi.mp h0) i) n hG
intro j
exact (hcon (hg.1 i j)).trans (hgB i j n (by omega))
have hb1 : ‖iteratedFDeriv ℝ n
(fun v d i j => coordPartial d (fun p => g p i j) (statePoint v)) w‖ ≤ G := by
apply norm_iteratedFDeriv_pi_le h1 n hG
intro d
apply norm_iteratedFDeriv_pi_le ((contDiffAt_pi.mp h1) d) n hG
intro i
apply norm_iteratedFDeriv_pi_le ((contDiffAt_pi.mp ((contDiffAt_pi.mp h1) d)) i) n hG
intro j
exact ((hcon (partial_contDiffOn (hg.1 i j) hU d)).trans
(norm_iteratedFDeriv_coordPartial_le (hg.1 i j) hU hw d n)).trans
(hgB i j (n + 1) (by omega))
have hb2 : ‖iteratedFDeriv ℝ n
(fun v d e i j => coordPartial d (coordPartial e (fun p => g p i j)) (statePoint v)) w‖ ≤ G := by
apply norm_iteratedFDeriv_pi_le h2 n hG
intro d
apply norm_iteratedFDeriv_pi_le ((contDiffAt_pi.mp h2) d) n hG
intro e
apply norm_iteratedFDeriv_pi_le ((contDiffAt_pi.mp ((contDiffAt_pi.mp h2) d)) e) n hG
intro i
apply norm_iteratedFDeriv_pi_le
((contDiffAt_pi.mp ((contDiffAt_pi.mp ((contDiffAt_pi.mp h2) d)) e)) i) n hG
intro j
exact (((hcon (partial_contDiffOn (partial_contDiffOn (hg.1 i j) hU e) hU d)).trans
(norm_iteratedFDeriv_coordPartial_le (partial_contDiffOn (hg.1 i j) hU e) hU hw d n)).trans
(norm_iteratedFDeriv_coordPartial_le (hg.1 i j) hU hw e (n + 1))).trans
(hgB i j (n + 1 + 1) (by omega))
exact norm_iteratedFDeriv_prod_le h0 hB.snd n (hb0.trans (le_max_right _ _))
(norm_iteratedFDeriv_prod_le h1 hB.snd.snd n (hb1.trans (le_max_right _ _))
(norm_iteratedFDeriv_prod_le h2 hId n (hb2.trans (le_max_right _ _))
((norm_iteratedFDeriv_id_pos w hn).trans (le_max_left _ _))))
end SmoothLocal.HighEquation
end
end OAI