Coarse-graining support: Support.Sobolev.Fractional.CongruenceAE #
Imported from the Apache-2.0 CoarseGraining development at commit
c7ddd76c08ade64fed1b8d2ca51be14dfee8deb4.
Almost-everywhere congruence for the fractional Sobolev and Besov seminorms #
All quantities in the W^{s,p} versus B^s_{p,p} comparison are invariant
under modifying u on a null set of the cube. This file proves the
congruence lemmas once, against the canonical hypothesis
u =ᵐ[cubeMeasure Q] v:
gagliardoKernel_congr_ae,cubeGagliardoESeminorm_congr_ae,memWsp_congr_ae(generic targetE);cubeBesovOverlapSeminorm_congr_ae(scalar, allq);- the
ae-filter equivalence betweennormalizedCubeMeasure QandcubeMeasure Q.
These discharge the congr_ae item of the frozen API surface and enable the
measurability-free public wrapper of CG Lemma 1.3.
The normalized and plain cube measures have the same ae filter.
Kernel congruence: modifying u on a cube-null set changes the Gagliardo
kernel only on a gagliardoCubeMeasure-null set of pairs.
A.e.-congruence of the fractional Sobolev seminorm.
A.e.-congruence of W^{s,p} membership.
Restriction of the congruence hypothesis to an overlap center's enlarged cube.
A.e.-congruence of the full overlapping Besov seminorm (any q).