The public statement CIV.Main.comparison #
This module proves the statement CIV.comparison, the first assertion of lem:aniso:comparison,
eq:aniso:comparison:conclusion. The proof is CIV.comparison_of_isDistributionalDriftDiffusion:
mollify in space, compare the mollified solution with the barrier eq:aniso:comparison:barrier
through the energy of eq:aniso:comparison:positive:energy from a reference time of the mollified
equation, let the mollification radius and then the barrier slope tend to zero, and exhaust I by
compact intervals. The hypothesis 1 ≤ d ≤ m of the statement is not used: for d = 0 the equation
has no diffusion and the argument applies verbatim, and for d > m the partial Laplacian is the
full Laplacian.
theorem
CIV.Main.comparison
(m d : ℕ)
(hd : 1 ≤ d ∧ d ≤ m)
(I : Set ℝ)
(hI : IsOpen I ∧ I.OrdConnected)
(B : CKN.Vec m × ℝ → CKN.Vec m)
(divB : CKN.Vec m × ℝ → ℝ)
(hB : IsAdmissibleDrift m I B divB)
(q : CKN.Vec m × ℝ → ℝ)
(hq : IsLocallyBoundedOn m I q)
(heq : IsDistributionalDriftDiffusion m d I B divB q)
:
∀ᵐ (τ₀ : ℝ) (τ : ℝ) ∂MeasureTheory.volume.restrict I, τ₀ < τ →
MeasureTheory.eLpNorm (fun (x : CKN.Vec m) => q (x, τ)) ⊤ MeasureTheory.volume ≤ MeasureTheory.eLpNorm (fun (x : CKN.Vec m) => q (x, τ₀)) ⊤ MeasureTheory.volume
The public statement of lem:aniso:comparison, first assertion.