openAI-math-dataset / lean /OAI /Geometry /RuledCovering /SingularAsymptotics.lean
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Add lean source and binary files (part 75)
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import OAI.Geometry.RuledCovering.EnergyIntegral
namespace OAI
noncomputable section
open Set MeasureTheory Filter Metric
open scoped Topology ContDiff Pointwise
namespace RuledApproximation
lemma singular_weighted_integral_tendsto {p gamma : ℝ} (hp : 1 < p) (hp2 : p ≤ 2) (hg : 1 < gamma) :
Tendsto (fun c : ℝ =>
((∫ z in singularDomain p gamma c, physicalWeight (Real.sqrt 2) (c • singularField p z))-1/4)/c^2)
(𝓝[>] 0) (𝓝 (singularCoefficient p)) := by
have ht := (singularDomain_volume_tendsto (by linarith : 0 ≤ p) hp2 hg).add
(energyCorrection_integral_tendsto hp hp2 (by linarith : 0 < gamma))
have hlim : (∫ b in Icc (-(1/2:ℝ)) (1/2), ceilingPolynomial p b) +
-(∫ z in coneTriangle (1/2), singularEnergy p z)/2 = singularCoefficient p := by
rw [neg_div,← sub_eq_add_neg]
exact singular_exact_coefficient hp
rw [hlim] at ht
apply ht.congr'
filter_upwards [self_mem_nhdsWithin] with c hc
have hc0 : c ≠ 0 := ne_of_gt hc
rw [singular_weighted_integral_expansion hp gamma c]
field_simp
ring
lemma singular_totalCost_quotient_tendsto {p gamma : ℝ} (hp : 1 < p) (hp2 : p ≤ 2) (hg : 1 < gamma) :
Tendsto (fun c : ℝ =>
(2*singularCost p gamma c+8*Real.sqrt 2*(c^gamma)^2-Real.sqrt 2/2)/c^2)
(𝓝[>] 0) (𝓝 (2*Real.sqrt 2*singularCoefficient p)) := by
have ht := ((singular_weighted_integral_tendsto hp hp2 hg).const_mul (2*Real.sqrt 2)).add
((singular_tip_small hg).tendsto_div_nhds_zero.const_mul (8*Real.sqrt 2))
simp only [mul_zero,add_zero] at ht
apply ht.congr'
filter_upwards with c
unfold singularCost
ring
lemma singular_asymptotic {p gamma : ℝ} (hp : 1 < p) (hp2 : p ≤ 2) (hg : 1 < gamma) :
Asymptotics.IsLittleO (𝓝[>] (0:ℝ))
(fun c => 2*singularCost p gamma c+8*Real.sqrt 2*(c^gamma)^2-
(Real.sqrt 2/2+2*Real.sqrt 2*singularCoefficient p*c^2))
(fun c => c^2) := by
rw [Asymptotics.isLittleO_iff_tendsto']
· have ht := (singular_totalCost_quotient_tendsto hp hp2 hg).sub_const (2*Real.sqrt 2*singularCoefficient p)
simp only [sub_self] at ht
apply ht.congr'
filter_upwards [self_mem_nhdsWithin] with c hc
have hc0 : c ≠ 0 := ne_of_gt hc
field_simp
ring
· filter_upwards [self_mem_nhdsWithin] with c hc
exact fun h => False.elim ((pow_ne_zero 2 (ne_of_gt hc)) h)
lemma singular_totalCost_small {p gamma : ℝ} (hp : 1 < p) (hp2 : p ≤ 2) (hg : 1 < gamma)
(hk : singularCoefficient p < 0) :
∀ᶠ c : ℝ in 𝓝[>] 0,
2*singularCost p gamma c+8*Real.sqrt 2*(c^gamma)^2 < Real.sqrt 2/2 := by
have hk' : 2*Real.sqrt 2*singularCoefficient p < 0 := mul_neg_of_pos_of_neg
(mul_pos (by norm_num) (Real.sqrt_pos.mpr (by norm_num))) hk
filter_upwards [self_mem_nhdsWithin,
(singular_totalCost_quotient_tendsto hp hp2 hg).eventually (gt_mem_nhds hk')] with c hc hcost
exact sub_neg.mp (by simpa only [zero_mul] using (div_lt_iff₀ (sq_pos_of_pos hc)).mp hcost)
end RuledApproximation
end
end OAI