Monotonicity #
Ported from scottnarmstrong/Superdiffusion at 7f20476385d4af418f110303085ad0740c9eba46. Module imports, support namespace and local option directives adapted for Lean Pool.
Loewner monotonicity of the annealed cutoff cube matrices #
ABK26: by subadditivity, the matrices bfAhom_m(cu_n) are monotone
nonincreasing in n in the Loewner (positive semidefinite) order. The paper
places no sign restriction on n, and the consumers instantiate the statement
at every n ∈ ℤ, so the monotonicity below is stated for all n ≤ k in ℤ.
Three inputs go into the proof.
- The deterministic a.e. block subadditivity comparison
Ch04.RestrictionLawCarrier.coarseBlockMatrix_le_descendantsAverageBlockMat_aeand the block quadratic-form machinery ofCh04.blockMatLoewnerLE_of_integral_quadratic_monoare supplied by CoarseGraining and are scale-free. - Entrywise integrability of the coarse block matrix on the parent cube and on each of its
descendants is discharged from the proved cutoff moment layer:
integrable_LambdaSqCoeffField_pow_cutoffLawandintegrable_lambdaSqCoeffField_inv_pow_cutoffLawhold for the unnormalized cutoff law on an arbitrary triadic cube, so CoarseGraining's factor-moment routeCh04.RestrictionLawCarrier.integrable_coarseFullBlockMatrixAtCube_of_integrable_factor_observablesapplies verbatim. No(P4)record and no structural-law hypothesis is needed. - The stationary transfer identifying the expectation on a descendant cube with
the expectation on the origin cube at the descendant scale. This is the only
step that is not scale-free in CoarseGraining:
Ch04.RestrictionLawCarrier.blockMatLoewnerLE_annealedBlockMatrixAtScaleroutes it throughRestrictionStationaryLaw = IsStationaryR, which only sees integer translations, whereas a descendant offset3 ^ n * zis an integer vector only forn ≥ 0. The genuine cutoff law is invariant under every real translation, so this repository reroutes the transfer throughAlgsuperdiff.Section3.Cutoff.coefficientCutoffLaw_stationary_realand the scale-free geometry ofProvider.Annealed.RealStationaryTransfer. That removes the sign restriction entirely.
Main results #
The full unfolded coarse block observable of the genuine cutoff is integrable on every triadic cube. Both factor moments are the proved cutoff moments at exponent one.
Every entry of the doubled coarse block matrix of the genuine cutoff is integrable on every triadic cube.
Real-translation invariance of the genuine cutoff law, in the form consumed by the scale-free transfer layer.
Descendant averages of the coarse block entries #
The Loewner monotonicity #
ABK26. The annealed cutoff block matrices on origin cubes are
nonincreasing in the cube scale in the Loewner order, at every pair of integer
scales n ≤ k.