Appendix C composition in L1 and L2, retaining the same averaged norm. Only the L2 input includes order zero.
theorem
AVenhance.Infra.Ergodic.spatialJet_eLpNorm_two_eq
{d n : ℕ}
{f : Homogenization.Vec d → ℂ}
(hf : ContDiff ℝ (↑⊤) f)
(w : Fin n → Fin d)
:
MeasureTheory.eLpNorm (spatialJet n f w) 2 (MeasureTheory.volume.restrict (Torus.unitCell d)) = ENNReal.ofReal ((∫ (x : Homogenization.Vec d) in Torus.unitCell d, ‖spatialJet n f w x‖ ^ 2) ^ (1 / 2))
theorem
AVenhance.Infra.Ergodic.hasCoordinateAnalyticL2Bounds_comp_of_mixed_bounds
{d : ℕ}
(hd : 0 < d)
(X : PeriodicVolumePreservingDiffeomorphism d)
{Cf r CX R : ℝ}
(hCf : 0 ≤ Cf)
(hr : 0 < r)
(hCX : 0 < CX)
(hR : 0 < R)
{f : Homogenization.Vec d → ℂ}
(hf : ContDiff ℝ (↑⊤) f)
(hper : Torus.IsZdPeriodic f)
(hfbound :
∀ (n : ℕ) (w : Fin n → Fin d),
(∫ (x : Homogenization.Vec d) in Torus.unitCell d, ‖spatialJet n f w x‖ ^ 2) ^ (1 / 2) ≤ Cf * ↑n.factorial / r ^ n)
(hXbound :
∀ (n : ℕ) (w : Fin n → Fin d),
0 < n → ∀ (x : Homogenization.Vec d) (j : Fin d), |spatialJet n X.toFun w x j| ≤ CX * ↑n.factorial * R ^ n)
:
Full mixed L2 input, including zero, gives the composed L2 predicate without any pointwise bound on the outer function.