1826 — Physical Gradient Geometry Reduces Thirty Region Pairs to Seven Coupled Candidates
Census
After Entries 1824--1825, the source-compatible pair frontier consists of thirty region--region orbits. Their two-edge cut supports divide as
One-edge overlap
Write the two physical gradients as
where all 's are unit vectors. Positive Landau multipliers require for some , hence
The coefficient equals the sum of the other two coefficients. The unit-vector triangle inequality must therefore be saturated. This forces
and consequently
Thus no one-edge-overlap orbit supports a genuinely coupled cancellation of two nonzero physical gradients. Any survivor belongs to the simultaneous stationary loci of the individual region walls and must be treated as an iterated one-wall endpoint problem.
Same-cut profiles
The two same-cut profiles already force . Their identical gradients cannot cancel with positive multipliers unless stationary, and their wall equations then lie on existing soft support.
Result
This is a typing reduction, not a claim that the simultaneous stationary loci vanish. It separates those iterated endpoint objects from ordinary two-wall physical pinches.
Next falsifier
For the seven disjoint-cut representatives, solve the two wall equations together with antiparallel, nonzero physical gradients and positive multipliers. Apply the open physical-domain gate before constructing any ambient resultant or period system.
Evidence
research/benincasa/checkers/five_site_region_pair_physical_gradient_reduction.pyresearch/benincasa/results/five-site-region-pair-physical-gradient-reduction.json- allocator claim:
seqclaim-1043cc2a10fb87bc8593ed91