openAI-math-dataset / lean /OAI /Geometry /PrescribedRicci /ComplexIntegrationByParts.lean
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Add lean source and binary files (part 71)
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import Mathlib
import OAI.Geometry.PrescribedPotential.GlobalSobolev
import OAI.Geometry.PrescribedRicci.KahlerCofactorDivergence
namespace OAI
/-! Complex Integration By Parts. -/
noncomputable section
open Matrix Filter Set Topology MeasureTheory
open scoped ContDiff ComplexOrder Matrix.Norms.Elementwise
namespace Anticanonical.SourceSmooth
namespace KaehlerMetric
variable {d : ℕ}
def barDeriv (f : Coordinates d → ℂ) (z : Coordinates d) (j : Fin d) : ℂ :=
(2 : ℂ)⁻¹ * (fderiv ℝ f z (coordinateVector j) +
Complex.I * fderiv ℝ f z (Complex.I • coordinateVector j))
def holDeriv (f : Coordinates d → ℂ) (z : Coordinates d) (j : Fin d) : ℂ :=
(2 : ℂ)⁻¹ * (fderiv ℝ f z (coordinateVector j) -
Complex.I * fderiv ℝ f z (Complex.I • coordinateVector j))
lemma contDiff_deriv_direction {E F : Type*} [NormedAddCommGroup E] [NormedSpace ℝ E]
[NormedAddCommGroup F] [NormedSpace ℝ F] {f : E → F}
(hf : ContDiff ℝ ∞ f) (v : E) : ContDiff ℝ ∞ (fun z => fderiv ℝ f z v) :=
(hf.fderiv_right (by simp)).clm_apply contDiff_const
lemma contDiff_barDeriv {f : Coordinates d → ℂ} (hf : ContDiff ℝ ∞ f) (j : Fin d) :
ContDiff ℝ ∞ (fun z => barDeriv f z j) :=
contDiff_const.mul ((contDiff_deriv_direction hf _).add
(contDiff_const.mul (contDiff_deriv_direction hf _)))
lemma contDiff_holDeriv {f : Coordinates d → ℂ} (hf : ContDiff ℝ ∞ f) (j : Fin d) :
ContDiff ℝ ∞ (fun z => holDeriv f z j) :=
contDiff_const.mul ((contDiff_deriv_direction hf _).sub
(contDiff_const.mul (contDiff_deriv_direction hf _)))
lemma compactSupport_barDeriv {f : Coordinates d → ℂ} (hf : HasCompactSupport f)
(j : Fin d) : HasCompactSupport (fun z => barDeriv f z j) := by
exact ((hf.fderiv_apply ℝ (coordinateVector j)).add
(hf.fderiv_apply ℝ (Complex.I • coordinateVector j)).mul_left).mul_left
lemma integrable_mul_deriv {f g : Coordinates d → ℂ}
(hf : ContDiff ℝ ∞ f) (hg : ContDiff ℝ ∞ g) (hc : HasCompactSupport f)
(v : Coordinates d) : Integrable (fun z => f z * fderiv ℝ g z v) :=
(hf.continuous.mul (contDiff_deriv_direction hg v).continuous).integrable_of_hasCompactSupport
hc.mul_right
lemma integrable_deriv_mul {f g : Coordinates d → ℂ}
(hf : ContDiff ℝ ∞ f) (hg : ContDiff ℝ ∞ g) (hc : HasCompactSupport f)
(v : Coordinates d) : Integrable (fun z => fderiv ℝ f z v * g z) :=
((contDiff_deriv_direction hf v).continuous.mul hg.continuous).integrable_of_hasCompactSupport
(hc.fderiv_apply ℝ v).mul_right
lemma contDiffAt_deriv_direction {E F : Type*} [NormedAddCommGroup E] [NormedSpace ℝ E]
[NormedAddCommGroup F] [NormedSpace ℝ F] {f : E → F} {z : E}
(hf : ContDiffAt ℝ ∞ f z) (v : E) : ContDiffAt ℝ ∞ (fun y => fderiv ℝ f y v) z :=
(hf.fderiv_right (by simp)).clm_apply contDiffAt_const
lemma continuous_mul_on_tsupport {E : Type*} [TopologicalSpace E] {f g : E → ℂ}
(hf : Continuous f) (hg : ∀ z ∈ tsupport f, ContinuousAt g z) :
Continuous (fun z => f z * g z) := by
rw [continuous_iff_continuousAt]
intro z
by_cases hz : z ∈ tsupport f
· exact hf.continuousAt.mul (hg z hz)
· apply (continuousAt_const (y := (0 : ℂ))).congr
filter_upwards [notMem_tsupport_iff_eventuallyEq.mp hz] with y hy
simp only [hy, zero_mul, Pi.zero_apply]
lemma contDiff_mul_on_tsupport {E : Type*} [NormedAddCommGroup E] [NormedSpace ℝ E]
{f g : E → ℂ} (hf : ContDiff ℝ ∞ f)
(hg : ∀ z ∈ tsupport f, ContDiffAt ℝ ∞ g z) :
ContDiff ℝ ∞ (fun z => f z * g z) := by
rw [contDiff_iff_contDiffAt]
intro z
by_cases hz : z ∈ tsupport f
· exact hf.contDiffAt.mul (hg z hz)
· apply (contDiffAt_const (c := (0 : ℂ))).congr_of_eventuallyEq
filter_upwards [notMem_tsupport_iff_eventuallyEq.mp hz] with y hy
simp only [hy, zero_mul, Pi.zero_apply]
lemma integrable_mul_deriv_local {f g : Coordinates d → ℂ}
(hf : ContDiff ℝ ∞ f) (hg : ∀ z ∈ tsupport f, ContDiffAt ℝ ∞ g z)
(hc : HasCompactSupport f) (v : Coordinates d) :
Integrable (fun z => f z * fderiv ℝ g z v) :=
(continuous_mul_on_tsupport hf.continuous (fun z hz =>
(contDiffAt_deriv_direction (hg z hz) v).continuousAt)).integrable_of_hasCompactSupport
hc.mul_right
lemma integrable_deriv_mul_local {f g : Coordinates d → ℂ}
(hf : ContDiff ℝ ∞ f) (hg : ∀ z ∈ tsupport f, ContDiffAt ℝ ∞ g z)
(hc : HasCompactSupport f) (v : Coordinates d) :
Integrable (fun z => fderiv ℝ f z v * g z) :=
(continuous_mul_on_tsupport (contDiff_deriv_direction hf v).continuous (fun z hz =>
(hg z (tsupport_fderiv_apply_subset ℝ v hz)).continuousAt)).integrable_of_hasCompactSupport
(hc.fderiv_apply ℝ v).mul_right
lemma integral_mul_barDeriv_local {f g : Coordinates d → ℂ}
(hf : ContDiff ℝ ∞ f) (hg : ∀ z ∈ tsupport f, ContDiffAt ℝ ∞ g z)
(hc : HasCompactSupport f) (j : Fin d) :
(∫ z, f z * barDeriv g z j) = -(∫ z, barDeriv f z j * g z) := by
have hv (v : Coordinates d) : (∫ z, f z * fderiv ℝ g z v) =
-(∫ z, fderiv ℝ f z v * g z) :=
integral_mul_fderiv_eq_neg_fderiv_mul_of_integrable
(integrable_deriv_mul_local hf hg hc v) (integrable_mul_deriv_local hf hg hc v)
((continuous_mul_on_tsupport hf.continuous (fun z hz => (hg z hz).continuousAt)).integrable_of_hasCompactSupport hc.mul_right)
(fun z _ => hf.differentiable (by simp) z)
(fun z hz => (hg z hz).differentiableAt (by simp))
have he (z : Coordinates d) : f z * barDeriv g z j =
(2 : ℂ)⁻¹ * (f z * fderiv ℝ g z (coordinateVector j)) +
((2 : ℂ)⁻¹ * Complex.I) * (f z * fderiv ℝ g z (Complex.I • coordinateVector j)) := by
unfold barDeriv
ring
have he' (z : Coordinates d) : barDeriv f z j * g z =
(2 : ℂ)⁻¹ * (fderiv ℝ f z (coordinateVector j) * g z) +
((2 : ℂ)⁻¹ * Complex.I) * (fderiv ℝ f z (Complex.I • coordinateVector j) * g z) := by
unfold barDeriv
ring
simp_rw [he, he']
rw [integral_add ((integrable_mul_deriv_local hf hg hc _).const_mul _) ((integrable_mul_deriv_local hf hg hc _).const_mul _),
integral_add ((integrable_deriv_mul_local hf hg hc _).const_mul _) ((integrable_deriv_mul_local hf hg hc _).const_mul _)]
simp only [integral_const_mul, hv]
ring
end KaehlerMetric
end Anticanonical.SourceSmooth
end
end OAI