Natural material-square integrability from actual initial-time carriers.
theorem
AVenhance.Infra.Section4.iterate_material_square_time_integrable
{u : ℝ → Homogenization.Vec 2 → ℝ}
{b : ℝ → Homogenization.Vec 2 → Homogenization.Vec 2}
(hb : ContinuousOn (fun (z : AmnrSpace) => b z.1 z.2) (Set.Ici 0 ×ˢ Set.univ))
(hu : ContDiffOn ℝ 1 (fun (z : AmnrSpace) => u z.1 z.2) (Set.Ici 0 ×ˢ Set.univ))
{s : ℝ}
(hs : 0 ≤ s)
:
MeasureTheory.Integrable (fun (z : AmnrSpace) => amnrMaterial b u z.1 z.2 ^ 2)
((MeasureTheory.volume.restrict (Set.uIoc 0 s)).prod (MeasureTheory.volume.restrict unitCube))
The material square has a continuous within-derivative representative; no two-sided initial-time derivative is assumed.
theorem
AVenhance.Infra.Section4.iterate_material_square_integrable
{u : ℝ → Homogenization.Vec 2 → ℝ}
{b : ℝ → Homogenization.Vec 2 → Homogenization.Vec 2}
(hb : ContinuousOn (fun (z : AmnrSpace) => b z.1 z.2) (Set.Ici 0 ×ˢ Set.univ))
(hu : ContDiffOn ℝ 1 (fun (z : AmnrSpace) => u z.1 z.2) (Set.Ici 0 ×ˢ Set.univ))
:
MeasureTheory.IntegrableOn (fun (z : AmnrSpace) => amnrMaterial b u z.1 z.2 ^ 2) timeCube MeasureTheory.volume
Actual material squares are naturally integrable on the open cell.