Annulus energy between level-separated circles is bounded by the loop actions
ProvedFiniteEnergyPlane.lintegral_energyDensity_annulus_le_loopActionLet be a strictly star-shaped level with contact form and -compatible complex structure on , and let be a finite-energy -holomorphic curve on the punctured unit disc. For a level let , where is Mathlib's smooth transition function ( on , on ), so is an admissible function in Hofer's energy. Let , and suppose that on each circle either everywhere or everywhere. Then
where is the action of the clockwise loop .
In words: the Hofer-energy integrand at level over an annulus whose boundary circles avoid the slab is controlled by the actions of the two boundary loops. This is a step in the zero-charge case of the asymptotic description of finite-energy punctured discs (Hofer; Wendl, Theorem 9.8).
Formalization Note is identified with by , and is aCoord H. The integrand of with respect to is energyDensity H φ u; the integral is the lower Lebesgue integral of its positive part over ball 0 ρ₁ \ ball 0 ρ₂, and is loopAction H u (cwLoop 0 ρ).
import Definitions.Def_FiniteEnergyPlane_Setting import Mathlib.Analysis.SpecialFunctions.SmoothTransition
namespace FiniteEnergyPlane
open MeasureTheory Metric Filter Topology
open scoped ContDiff ENNReal Real
/-- Annulus energy between level-separated circles is bounded by the loop actions. Let
`φ_A(s) = smoothTransition(s - A)²` (`0` for `s ≤ A`, `1` for `s ≥ A + 1`), and let
`0 < ρ₂ < ρ₁ < 1` be radii such that on each of the two circles `‖z‖ = ρᵢ` the coordinate
`a = aCoord ∘ u` stays either `≤ A` or `≥ A + 1`. Then the integral of the energy density
`u*d(φ_A(a) λ)` over the annulus `ρ₂ ≤ ‖z‖ < ρ₁` is at most `|Q(ρ₁)| + |Q(ρ₂)|`, where `Q` is the
action of the clockwise loop. -/
theorem lintegral_energyDensity_annulus_le_loopAction {n : ℕ} (H : V n → ℝ)
(hH : IsStrictlyStarShapedLevel H) (J : V n → V n →L[ℝ] V n)
(hJ : IsCompatibleXiStructure H J) (u : ℂ → V n)
(hu : IsFiniteEnergyCurve H J (ball 0 1 \ {0}) u) (A ρ₁ ρ₂ : ℝ) (h₂ : 0 < ρ₂)
(h₂₁ : ρ₂ < ρ₁) (h₁ : ρ₁ < 1)
(hc₁ : (∀ z : ℂ, ‖z‖ = ρ₁ → aCoord H (u z) ≤ A) ∨
(∀ z : ℂ, ‖z‖ = ρ₁ → A + 1 ≤ aCoord H (u z)))
(hc₂ : (∀ z : ℂ, ‖z‖ = ρ₂ → aCoord H (u z) ≤ A) ∨
(∀ z : ℂ, ‖z‖ = ρ₂ → A + 1 ≤ aCoord H (u z))) :
∫⁻ z in ball 0 ρ₁ \ ball 0 ρ₂,
ENNReal.ofReal (energyDensity H (fun s => Real.smoothTransition (s - A) ^ 2) u z) ≤
ENNReal.ofReal (|loopAction H u (cwLoop 0 ρ₁)| + |loopAction H u (cwLoop 0 ρ₂)|) := by
sorry
end FiniteEnergyPlane