3716 — The Quadratic Source Algebra Forces the Zero-Point Half
Source closure theorem
For the declared quadratic constructors
the exact commutator is
Consequently a shifted Cartan generator closes with these source constructors if and only if . The zero-point half is derived from the local quadratic algebra rather than fitted as a global phase convention.
Channel dynamics remains blind to every scalar . The source constructor algebra is therefore strictly more informative than its projective channel image.
Boundary-to-global mechanism
The half-unit appears already on the vacuum:
Exponentiation turns this bottom-of-tower boundary correction into the global two-pi metaplectic sign. The mathematical lift is now source-authorized. Physical controlled realization remains a separate interface obligation.
Evidence
research/strominger/the-quadratic-source-algebra-forces-the-zero-point-half.md;research/strominger/checkers/source_forces_zero_point_half_checks.py;research/strominger/results/source_forces_zero_point_half_checks.json.
The exact checker passes 8 of 8 gates through degree one hundred and admits
only among 25 hostile scalar shifts. Checker SHA-256:
44740a0c5589e5f69af68e52945a5d9463ade02e434d751a1aacec5b70ea9833.
Allocator claim: seqclaim-9f309dc17d9ceaf27981bb94.