Documentation

LeanPool.Superdiffusion.Algsuperdiff.Section3.Provider.Homogenization.TwoLaneCoverDepth

TwoLaneCoverDepth #

Ported from scottnarmstrong/Superdiffusion at 7f20476385d4af418f110303085ad0740c9eba46. Module imports, support namespace and local option directives adapted for Lean Pool.

The deterministic lane-separated cover of the observation cube #

This module is the deterministic half of the lane-separated observation-scale transport of Provider/Homogenization/TwoLaneCoverTransport.lean; it is separated to keep each Lean file focused and below the repository line limit. It contains no probability: every statement here is a pointwise inequality at a fixed sample point, and the two cell families it is run against are arbitrary.

Fix a coefficient cutoff scale L, an observation cube square_m and two cell families g, h on the cubes. The squared raw homogenization error of square_m, read at the discount 1/8, expands into weighted depth layers. The first m - L layers are coarse: each is dominated by the maximum, over that layer's parents, of the average of the cell family over their scale-L descendants (laneParentAverage). The remaining layers are fine: they sit below the cutoff scale and are dominated, with a geometrically summable factor (laneFineFactor), by the maximum of the cell family over all scale-L cells of the observation cube (laneCellSup). Every step is monotone in the cell family and the two maxima are subadditive, so a cover of the squared raw cell errors by g + h splits the whole deterministic bound into one cover functional per lane (laneTotal). That is the content of the endpoint of this module, cutoffHomogenizationErrorRaw_sq_le_laneTotal_add.

No comparator change occurs anywhere: the coefficient cutoff is a_L and the normalizer is sigmabar_L at the cell scale, at every intermediate scale and at the observation cube. The discounts t = 1/8 at the observation cube and u = 1/16 at the cells are the ones fixed by the corrected Step 4 of p.combine.under.S; see the References of Provider/Homogenization/TwoLaneCoverTransport.lean.

The declarations below are local Provider results.

Two elementary facts about the finite averages and suprema of the cover #

The cover functional of one lane #

The layer-ell parent maximum of the descendant averages of one cell family.

Equations
  • One or more equations did not get rendered due to their size.
Instances For

    The coarse part of the cover functional: the first m - L layers.

    Equations
    • One or more equations did not get rendered due to their size.
    Instances For

      The maximum of one cell family over all scale-L cells of the observation cube.

      Equations
      • One or more equations did not get rendered due to their size.
      Instances For

        The geometric factor paid by the fine tail below the cutoff scale.

        Equations
        • One or more equations did not get rendered due to their size.
        Instances For

          The full cover functional of one cell family.

          Equations
          • One or more equations did not get rendered due to their size.
          Instances For

            The deterministic cover, split over the two lanes #

            The squared raw cutoff error of a scale-L cell, read at the cell window 1/16.

            Equations
            • One or more equations did not get rendered due to their size.
            Instances For

              The layer-ell term of the weighted-depth expansion of the squared raw error of the observation cube.

              Equations
              • One or more equations did not get rendered due to their size.
              Instances For

                The geometric series of the fine tail #