Coarse-graining support: #
Support.Book.Ch04.Internal.FixedCompetitorEnergyMeasurability.Measurability
Imported from the Apache-2.0 CoarseGraining development at commit
c7ddd76c08ade64fed1b8d2ca51be14dfee8deb4.
Fixed-competitor energy measurability, first atoms #
Audit tag (Ch4 rebuild contract CH04_REBUILD_SURFACE_2026-05-16.md) #
Internal claim: the PointwiseLocalSigma-measurable scalar atoms (single-vector
dot products, single-coordinate matrix-vector products, etc.) used as the
local-σ-measurable building blocks for fixed-competitor energy observables.
First layer of the internal HasMeasurableMuFamily cleanup.
Consumed by (within Internal/FixedCompetitorEnergyMeasurability/):
LipschitzBounds.lean, which lifts these atoms to Borel-measurable
fixed-coefficient maps; ultimately reaches the public
Theorems/Mu.lean :: aemeasurable_Mu_cubeSet via the chain
Measurability → LipschitzBounds → Integrals → BlockEnergyAverage → MuObservable → AEESliceAssembly/MuFamily.
If the single-claim summary above grows into three or more distinct claims, split or refactor per the rebuild contract.
Mathlib's global smooth compact-support density, converted to the exact toLp
representative shape used by the probability bookkeeping.
The later local argument still has to push these probes inside U; this lemma isolates the
ambient density input from that boundary-cutoff step.
Localize a smooth L² matrix field to an open finite-measure set without
changing it much in L². This is the analytic cutoff step that turns
Mathlib's ambient compactly supported smooth density into the note-facing
tsupport ⊆ U probe class.
Smooth compactly supported HilbertMat probes with support contained in an
open finite-measure set are dense in L²(U; HilbertMat d).
On an open finite-measure domain, the quantitative-slice coefficient field
as an L² Hilbert-matrix object is measurable for the local sigma algebra.
On an open finite-measure domain, the essential quantitative-slice
coefficient field as an L² Hilbert-matrix object is measurable for the local
sigma algebra.
Smooth probes supported in the open core of a triadic cube are dense for the half-open cube, because the two restricted volume measures agree.
On a half-open triadic cube, the essential quantitative-slice coefficient
field as an L² Hilbert-matrix object is measurable for the local sigma
algebra.
Smooth-probe coordinate pairings of the AEE L² coefficient realization
are local-test measurable.
On an open finite-measure domain, the AEE quantitative-slice coefficient
field as an L² Hilbert-matrix object is measurable for the local sigma
algebra.
On a half-open triadic cube, the AEE quantitative-slice coefficient field
as an L² Hilbert-matrix object is measurable for the local sigma algebra.