RunningDiffusivityBridge #
Ported from scottnarmstrong/Superdiffusion at 7f20476385d4af418f110303085ad0740c9eba46. Module imports, support namespace and local option directives adapted for Lean Pool.
construction of the infinite-volume annealed diffusivity #
CoarseGraining defines barSigmaLimit as the infimum of the scalarized
annealed upper coefficients. Its Section 5.7 public positivity and primal/dual
identification lemmas are stated under the stronger
GammaSigmaCoarseGrainedEllipticity input. This file records that
non-circular route for the Section 3 cutoff law.
The last theorem transports the resulting limit back across the triadic
normalization used to obtain CoarseGraining's unit-range structural law. The
conclusion is stated for the honest full matrices, since the auxiliary
BlockMat record does not carry a topology.
Under (P4), the scalarized upper annealed coefficients converge to
CoarseGraining's barSigmaLimit.
Under (P4), the scalarized starred annealed coefficients converge to
CoarseGraining's barSigmaStarLimit.
(P4) already makes CoarseGraining's limiting upper scalar strictly positive.
Under (P4), the upper and starred annealed scalar limits coincide.
Under (P4), the starred scalar coefficients converge to the same positive scalar
as the upper coefficients.
Under (P4), the honest full annealed block matrices converge entrywise to the
block diagonal with the single positive scalar barSigmaLimit and its inverse.
Spatial normalization does not alter the infinite-volume coefficient.
If a triadically normalized pushforward of P satisfies CoarseGraining's
structural law and (P4), then the unnormalized annealed matrices converge to
the same block diagonal. This is the bridge needed when the original cutoff
has range sqrt d * 3^m rather than CoarseGraining's normalized unit range.
The positive scalar in an infinite-volume block-diagonal limit is unique.
A normalized structural law with (P4) gives existence and uniqueness of the
positive scalar describing the unnormalized infinite-volume annealed block
limit.