Normalizing the physical Gaussian average #
After the affine change of variables, the physical average estimate has the dyadic form used in the high-strip cell summation.
theorem
ESS.bu_short_normalized_average_bound
(scale β M C δ d : ℝ)
(Y : CKN.Foundation.Parabolic.Vec3)
(hscale : 0 < scale)
(hβ : 0 < β)
(hC : 0 ≤ C)
(hδ : 0 < δ)
(hδd : δ ≤ d)
(hd : d ≤ 1)
(w : CKN.Foundation.Parabolic.ParabolicPoint → CKN.Foundation.Parabolic.Vec3)
(hFm :
MeasureTheory.AEStronglyMeasurable
(fun (z : CKN.Foundation.Parabolic.ParabolicPoint) => CKN.Foundation.Parabolic.vec3EuclideanNorm (w z) ^ 2)
(MeasureTheory.volume.restrict
(CKN.spaceTimeSet (CKN.Foundation.Parabolic.vec3Ball (scale • Y) (scale * √(3 * δ / 2)))
(Set.Ioo (scale ^ 2 * δ / 2) (5 * scale ^ 2 * δ / 4)))))
(hPhysical :
have t := scale ^ 2 * δ / 2;
t.rpow (-(5 / 2)) * ∫ (z : CKN.Foundation.Parabolic.ParabolicPoint) in CKN.spaceTimeSet (CKN.Foundation.Parabolic.vec3Ball (scale • Y) (scale * √(3 * δ / 2))) (Set.Ioo t (5 * t / 2)), CKN.Foundation.Parabolic.vec3EuclideanNorm (w z) ^ 2 ≤ C * Real.exp (8 * M * CKN.Foundation.Parabolic.vec3EuclideanNorm (scale • Y) ^ 2) * Real.exp (-(β * (scale • Y) 2 ^ 2 / (12 * t))))
:
have v := buAffineField (-scale ^ 2 / 2) scale w;
have G := 8 * M * scale ^ 2;
have Avg :=
CKN.spaceTimeSet (CKN.Foundation.Parabolic.vec3Ball Y √(3 * δ / 2)) (Set.Ioo (1 / 2 + δ / 2) (1 / 2 + 5 * δ / 4));
∫ (z : CKN.Foundation.Parabolic.ParabolicPoint) in Avg, CKN.Foundation.Parabolic.vec3EuclideanNorm (v z) ^ 2 ≤ C * d ^ 2 * Real.exp (G * (Y 0 ^ 2 + Y 1 ^ 2 + Y 2 ^ 2)) * Real.exp (-(β * Y 2 ^ 2 / (12 * d)))
A physical Gaussian average estimate yields the corresponding
normalized dyadic average bound (lem:bu-small-time).