openAI-math-dataset / lean /OAI /Analysis /HenonEmden /CapContinuity.lean
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Add lean source and binary files (part 19)
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import OAI.Analysis.HenonEmden.CapOscillation
namespace OAI
universe uE
section CapContinuity
open MeasureTheory Set Metric Filter Topology
noncomputable section
namespace HenonLaneEmden.AdaptiveCap
open Cutoff CapWeights
variable {E : Type uE} [NormedAddCommGroup E] [InnerProductSpace ℝ E]
[MeasurableSpace E] [BorelSpace E] [FiniteDimensional ℝ E] [Nontrivial E]
(μ : Measure E) [μ.IsAddHaarMeasure]
lemma weight_short_oscillation {κ δ : ℝ} (hκ : 0 < κ) (hκ1 : κ ≤ 1)
(hδ : 0 ≤ δ) (hδ1 : δ ≤ 1/2) {x y : E} (hd : 0 < d x)
(hxy : dist x y ≤ δ*(d x)^(m (Module.finrank ℝ E))) (e : sphere (0:E) 1) :
|weight μ κ e x-weight μ κ e y| ≤
oscillationConstant μ κ*δ*(d x)^(N (Module.finrank ℝ E)) := by
let n := Module.finrank ℝ E
have hn : 1 ≤ n := Module.finrank_pos
have hdist : dist x y ≤ d x/2 := by
have hp := pow_d_le_self x (show 1 ≤ m n by unfold m; omega)
calc
_ ≤ δ*(d x)^(m n) := hxy
_ ≤ δ*d x := mul_le_mul_of_nonneg_left hp hδ
_ ≤ _ := by nlinarith
have hh := weight_close_oscillation μ hκ hκ1 hd hdist e
have hc := oscillationConstant_nonneg μ hκ.le
calc
_ ≤ oscillationConstant μ κ*(d x)^(N n-n-1)*dist x y := hh
_ ≤ oscillationConstant μ κ*(d x)^(N n-n-1)*(δ*(d x)^(m n)) :=
mul_le_mul_of_nonneg_left hxy (mul_nonneg hc (pow_nonneg hd.le _))
_ = oscillationConstant μ κ*δ*(d x)^((N n-n-1)+m n) := by rw [pow_add]; ring
_ ≤ _ := by
apply mul_le_mul_of_nonneg_left _ (mul_nonneg hc hδ)
exact pow_le_pow_of_le_one hd.le (d_le_one x) (by change (k n) + n + 2 ≤ (k n + n + 2 - n - 1) + (n+3); omega)
lemma continuous_weight {κ : ℝ} (hκ : 0 < κ) (hκ1 : κ ≤ 1) (e : sphere (0:E) 1) :
Continuous (weight μ κ e) := by
rw [continuous_iff_continuousAt]
intro x
by_cases hd : 0 < d x
· rw [Metric.continuousAt_iff]
intro ε hε
let C := oscillationConstant μ κ*(d x)^(N (Module.finrank ℝ E)-Module.finrank ℝ E-1)
have hC : 0 ≤ C := mul_nonneg (oscillationConstant_nonneg μ hκ.le) (pow_nonneg hd.le _)
have hC1 : 0 < C+1 := by linarith
refine ⟨min (d x/2) (ε/(C+1)),lt_min (half_pos hd) (div_pos hε hC1),?_⟩
intro y hy
have hdist : dist x y < ε/(C+1) := by simpa only [dist_comm x y] using (lt_min_iff.mp hy).2
have hh := weight_close_oscillation μ hκ hκ1 hd (y := y)
(by simpa only [dist_comm] using (lt_min_iff.mp hy).1.le) e
change |weight μ κ e x-weight μ κ e y| ≤ C*dist x y at hh
rw [Real.dist_eq,abs_sub_comm]
have hb : (C+1)*dist x y < ε := by simpa only [mul_comm] using (lt_div_iff₀ hC1).mp hdist
have hr := dist_nonneg (x := x) (y := y)
nlinarith
· have hd0 : d x = 0 := le_antisymm (not_lt.mp hd) (d_nonneg x)
have hx : 2 ≤ ‖x‖ := not_lt.mp (fun hh => hd ((d_pos_iff x).mpr hh))
have hN : N (Module.finrank ℝ E)-Module.finrank ℝ E ≠ 0 := by unfold N; omega
have hcont : Continuous (fun y : E => boundConstant μ κ*(d y)^(N (Module.finrank ℝ E)-Module.finrank ℝ E)) :=
continuous_const.mul (continuous_d.pow _)
have ht : Tendsto (fun y : E => boundConstant μ κ*(d y)^(N (Module.finrank ℝ E)-Module.finrank ℝ E))
(𝓝 x) (𝓝 0) := by simpa only [hd0,zero_pow hN,mul_zero] using hcont.tendsto x
change Tendsto _ (𝓝 x) (𝓝 (weight μ κ e x))
rw [weight_outer μ κ e hx]
exact squeeze_zero (weight_nonneg μ κ e) (weight_bound μ hκ hκ1 e) ht
omit [BorelSpace E] [FiniteDimensional ℝ E] [Nontrivial E] [μ.IsAddHaarMeasure] in
lemma continuous_weight_direction (κ : ℝ) (x : E) :
Continuous (fun e : sphere (0:E) 1 => weight μ κ e x) := by
by_cases hx : x ≠ 0 ∧ 0 < d x
· simp only [weight,dite_eq_left hx,normalized]
exact continuous_const.mul ((continuous_profile _ _).div_const _)
· simp only [weight,dite_eq_right hx]; exact continuous_const
lemma measurable_weight {κ : ℝ} (hκ : 0 < κ) (hκ1 : κ ≤ 1) :
Measurable (fun z : sphere (0:E) 1 × E => weight μ κ z.1 z.2) := by
have hh : Measurable (fun z : E × sphere (0:E) 1 => weight μ κ z.2 z.1) :=
measurable_uncurry_of_continuous_of_measurable (continuous_weight μ hκ hκ1)
(fun x => (continuous_weight_direction μ κ x).measurable)
exact hh.comp measurable_swap
lemma weight_le_constant {κ : ℝ} (hκ : 0 < κ) (hκ1 : κ ≤ 1) (e : sphere (0:E) 1) (x : E) :
weight μ κ e x ≤ boundConstant μ κ := by
apply (weight_bound μ hκ hκ1 e x).trans
have hp := pow_le_one₀ (d_nonneg x) (d_le_one x) (n := N (Module.finrank ℝ E)-Module.finrank ℝ E)
simpa only [mul_one] using mul_le_mul_of_nonneg_left hp (boundConstant_nonneg μ hκ.le)
end HenonLaneEmden.AdaptiveCap
end
end CapContinuity
end OAI