Almost everywhere data on affine time intervals #
The heat inequality pulls back from the physical initial interval to the
shifted interval in lem:bu-small-time.
theorem
ESS.bu_affine_ae_pullback_interval
(τ scale a b : ℝ)
(hscale : 0 < scale)
(P : CKN.Foundation.Parabolic.ParabolicPoint → Prop)
(hP :
∀ᵐ (z :
CKN.Foundation.Parabolic.ParabolicPoint) ∂MeasureTheory.volume.restrict
(CKN.spaceTimeSet {x : CKN.Foundation.Parabolic.Vec3 | 0 < x 2}
(Set.Ioo (τ + scale ^ 2 * a) (τ + scale ^ 2 * b))), P z)
:
∀ᵐ (z :
CKN.Foundation.Parabolic.ParabolicPoint) ∂MeasureTheory.volume.restrict
(CKN.spaceTimeSet {x : CKN.Foundation.Parabolic.Vec3 | 0 < x 2} (Set.Ioo a b)), P (buAffinePoint τ scale z)
Almost everywhere statements pull back along a positive affine parabolic change of variables between corresponding time intervals.