Spatial scaling of the harmonic pressure supremum #
Positive spatial dilations preserve essential suprema up to the pressure amplitude, on any measurable region whose image stays in the interior ball.
theorem
ESS.pressureSplit_scaledSpatial_sup_le
{Ω : Set CKN.Foundation.Parabolic.Vec3}
(hΩ : MeasurableSet Ω)
{x₀ : CKN.Foundation.Parabolic.Vec3}
{r : ℝ}
(hr : 0 < r)
(himage : ∀ x ∈ Ω, CKN.scalingSpace r x₀ x ∈ CKN.euclideanBall 0 (3 / 4))
(p : CKN.Foundation.Parabolic.Vec3 → ℝ)
(hp : MeasureTheory.MemLp p (ENNReal.ofReal (3 / 2)) (MeasureTheory.volume.restrict (CKN.euclideanBall 0 1)))
:
MeasureTheory.eLpNorm (fun (x : CKN.Foundation.Parabolic.Vec3) => r ^ 2 * p (CKN.scalingSpace r x₀ x)) ⊤
(MeasureTheory.volume.restrict Ω) ≤ ENNReal.ofReal (r ^ 2) * MeasureTheory.eLpNorm p ⊤ (MeasureTheory.volume.restrict (CKN.euclideanBall 0 (3 / 4)))
The spatial pressure scaling is bounded by the source interior supremum on every measurable region whose image lies in the three-quarter ball.