diff --git a/Nevanlinna/complexHarmonic.lean b/Nevanlinna/complexHarmonic.lean index da7ec8b..94ad6d6 100644 --- a/Nevanlinna/complexHarmonic.lean +++ b/Nevanlinna/complexHarmonic.lean @@ -117,13 +117,17 @@ theorem im_of_holomorphic_is_harmonic {f : ℂ → ℂ} (h : Differentiable ℂ theorem logabs_of_holomorphic_is_harmonic {f : ℂ → ℂ} (h₁ : Differentiable ℂ f) - (h₂ : ∀ z, f z ≠ 0) : + (h₂ : ∀ z, f z ≠ 0) + (h₃ : ∀ z, f z ∈ Complex.slitPlane) : Harmonic (fun z ↦ Real.log ‖f z‖) := by -- f is real C² have f_is_real_C2 : ContDiff ℝ 2 f := ContDiff.restrict_scalars ℝ (Differentiable.contDiff h₁) + -- The norm square is z * z.conj + have normSq_conj : ∀ (z : ℂ), (starRingEnd ℂ) z * z = ↑‖z‖ ^ 2 := Complex.conj_mul' + -- The norm square is real C² have normSq_is_real_C2 : ContDiff ℝ 2 Complex.normSq := by unfold Complex.normSq @@ -149,7 +153,7 @@ theorem logabs_of_holomorphic_is_harmonic simp rw [Real.log_sqrt] rw [div_eq_inv_mul (Real.log (Complex.normSq (f z))) 2] - exact Complex.normSq_nonneg (f z) + exact Complex.normSq_nonneg (f z) rw [this] have : (2 : ℝ)⁻¹ • (Real.log ∘ Complex.normSq ∘ f) = (fun z ↦ (2 : ℝ)⁻¹ • ((Real.log ∘ ⇑Complex.normSq ∘ f) z)) := by @@ -169,5 +173,60 @@ theorem logabs_of_holomorphic_is_harmonic exact ContDiff.contDiffAt f_is_real_C2 · -- Laplace vanishes + have : (fun z ↦ Real.log ‖f z‖) = (2 : ℝ)⁻¹ • (Real.log ∘ Complex.normSq ∘ f) := by + funext z + simp + unfold Complex.abs + simp + rw [Real.log_sqrt] + rw [div_eq_inv_mul (Real.log (Complex.normSq (f z))) 2] + exact Complex.normSq_nonneg (f z) + rw [this] + rw [laplace_smul] + simp + + have : ∀ (z : ℂ), Complex.laplace (Real.log ∘ ⇑Complex.normSq ∘ f) z = 0 ↔ Complex.laplace (Complex.ofRealCLM ∘ Real.log ∘ ⇑Complex.normSq ∘ f) z = 0 := by + intro z + rw [laplace_compContLin] + simp + sorry + conv => + intro z + rw [this z] + + have : Complex.ofRealCLM ∘ Real.log ∘ Complex.normSq ∘ f = Complex.log ∘ Complex.ofRealCLM ∘ Complex.normSq ∘ f := by + unfold Function.comp + funext z + apply Complex.ofReal_log + exact Complex.normSq_nonneg (f z) + rw [this] + + have : Complex.ofRealCLM ∘ ⇑Complex.normSq ∘ f = ((starRingEnd ℂ) ∘ f) * f := by + funext z + simp + exact Complex.normSq_eq_conj_mul_self + rw [this] + + have : Complex.log ∘ (⇑(starRingEnd ℂ) ∘ f * f) = Complex.log ∘ ⇑(starRingEnd ℂ) ∘ f + Complex.log ∘ f := by + unfold Function.comp + funext z + simp + rw [Complex.log_mul_eq_add_log_iff] + + have : Complex.arg ((starRingEnd ℂ) (f z)) = - Complex.arg (f z) := by + rw [Complex.arg_conj] + have : ¬ Complex.arg (f z) = Real.pi := by + exact Complex.slitPlane_arg_ne_pi (h₃ z) + simp + tauto + rw [this] + simp + constructor + · exact Real.pi_pos + · exact Real.pi_nonneg + exact (AddEquivClass.map_ne_zero_iff starRingAut).mpr (h₂ z) + exact h₂ z + rw [this] sorry + sorry