OAI/NumberTheory/CubicMoment/Estimates/KernelScaling.lean

GitHub source file

8 declarations, 0 contain sorry, 0 declared as axioms

Scaling a cutoff kernel

The normalization and weighted L¹ moment are preserved under T k(Tx). Thus a single Schwartz kernel gives a uniform family of interval approximations at all positive truncation heights.

  1. def OAI.CubicFirstMoment.scaledKernel line 18
  2. theorem OAI.CubicFirstMoment.integrable_scaledKernel line 20
  3. theorem OAI.CubicFirstMoment.integral_scaledKernel line 24
  4. theorem OAI.CubicFirstMoment.scaledKernel_moment_integrand line 31
  5. theorem OAI.CubicFirstMoment.integrable_scaledKernel_moment line 39
  6. theorem OAI.CubicFirstMoment.kernelMoment_scaledKernel line 46
  7. theorem OAI.CubicFirstMoment.integrable_kernelMoment_schwartz line 55

    Source documentation

    Schwartz decay supplies the integrable moment needed by the cutoff, without imposing a quantitative tail estimate as a hypothesis.

    theorem integrable_kernelMoment_schwartz (k : SchwartzMap ℝ ℂ) :
        Integrable (fun y => ‖k y‖ * (1 + |y|)^2) := by
    …
  8. theorem OAI.CubicFirstMoment.scaled_schwartz_interval_error line 68

    Source documentation

    Uniform endpoint estimate for the entire scaled Schwartz family.

    theorem scaled_schwartz_interval_error (k : SchwartzMap ℝ ℂ)
        (hmass : ∫ y, k y = 1) {T : ℝ} (hT : 0 < T) (a b s : ℝ) :
        ‖(intervalStep a b s : ℂ) - intervalSmoothing (scaledKernel k T) a b s‖ ≤
          kernelMoment k 1 / (1 + T*|s-a|)^2 +
            kernelMoment k 1 / (1 + T*|s-b|)^2 := by
    …

    Mentions: OAI.CubicFirstMoment.intervalStep, OAI.CubicFirstMoment.intervalSmoothing, OAI.CubicFirstMoment.scaledKernel, OAI.CubicFirstMoment.kernelMoment