Centered Spectral Flow #
Support for the Armstrong–Vicol anomalous-diffusion formalization.
theorem
AVenhance.Infra.Ergodic.homogeneousHMinusOneNorm_le_of_fastPeriodicProduct_flow_without_product_mean
{d N : ℕ}
(hd : 0 < d)
(hN : 0 < N)
(X : PeriodicVolumePreservingDiffeomorphism d)
{f : Homogenization.Vec d → ℝ}
(hf : ContDiff ℝ (↑⊤) f)
(hper : IsZPeriodic f)
(Cf r : ℝ)
(hCf : 0 ≤ Cf)
(hr : 0 < r)
(hderivComp : HasCoordinateAnalyticL2Bounds (fun (x : Homogenization.Vec d) => ↑(f (X.toFun x))) Cf r)
{g : Homogenization.Vec d → ℝ}
(hg : MeasureTheory.LocallyIntegrable g MeasureTheory.volume)
(hg2 : MeasureTheory.LocallyIntegrable (fun (x : Homogenization.Vec d) => |g x| ^ 2) MeasureTheory.volume)
(hfast : IsFastPeriodic N g)
(hNr : 2 ≤ r * ↑N)
(hnear : FlowDerivativeNearIdentity X)
(hgMean : cellAverage g = 0)
:
(homogeneousHMinusOneNorm fun (x : Homogenization.Vec d) => f x * g (X.invFun x)) ≤ ENNReal.ofReal
(3 * ↑d ^ 2 * ((1 + 64 * ergodicFourierWeight d ^ (1 / 2) + 1024 * (↑d + 1)) / ↑N * (cellAverage fun (x : Homogenization.Vec d) => |f x| ^ 2) ^ (1 / 2) * (cellAverage fun (x : Homogenization.Vec d) => |g x| ^ 2) ^ (1 / 2) + (1 + 64 * ergodicFourierWeight d ^ (1 / 2) + 1024 * (↑d + 1)) * Cf * (cellAverage fun (x : Homogenization.Vec d) => |g x| ^ 2) ^ (1 / 2) * Real.exp (-r * ↑N / 4096)))