Crossing a unit slab of the symplectization costs a definite amount of energy
ProvedFiniteEnergyPlane.exists_pos_le_lintegral_energyDensity_annulusLet 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 ). Then there is a constant with the following property. For every level and all radii such that on one of the circles and on the other,
In words: whenever crosses a unit slab of the symplectization between two circles about the puncture, the Hofer-energy integrand at that level over the annulus is at least , and does not depend on the level or on the radii. 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.
import Definitions.Def_FiniteEnergyPlane_Setting import Mathlib.Analysis.SpecialFunctions.SmoothTransition
namespace FiniteEnergyPlane
open MeasureTheory Metric Filter Topology
open scoped ContDiff ENNReal Real
/-- Crossing a unit slab costs a definite amount of energy, uniformly in the level. Let
`φ_A(s) = smoothTransition(s - A)²`. There is `c > 0` such that for every level `A` and all radii
`0 < ρ₂ < ρ₁ < 1` for which `a = aCoord ∘ u` is `≤ A` on one of the circles `‖z‖ = ρᵢ` and
`≥ A + 1` on the other, the energy density `u*d(φ_A(a) λ)` integrates to at least `c` over the
annulus `ρ₂ ≤ ‖z‖ < ρ₁`. -/
theorem exists_pos_le_lintegral_energyDensity_annulus {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) :
∃ c : ℝ, 0 < c ∧ ∀ A ρ₁ ρ₂ : ℝ, 0 < ρ₂ → ρ₂ < ρ₁ → ρ₁ < 1 →
(((∀ z : ℂ, ‖z‖ = ρ₁ → aCoord H (u z) ≤ A) ∧
∀ z : ℂ, ‖z‖ = ρ₂ → A + 1 ≤ aCoord H (u z)) ∨
((∀ z : ℂ, ‖z‖ = ρ₁ → A + 1 ≤ aCoord H (u z)) ∧
∀ z : ℂ, ‖z‖ = ρ₂ → aCoord H (u z) ≤ A)) →
ENNReal.ofReal c ≤ ∫⁻ z in ball 0 ρ₁ \ ball 0 ρ₂,
ENNReal.ofReal (energyDensity H (fun s => Real.smoothTransition (s - A) ^ 2) u z) := by
sorry
end FiniteEnergyPlane