3749 — A Superselection Label Protects the Selector by Forbidding Its Interferometer
Superselection is insufficient
A strict superselection label supplies a nontrivial projector (P) commuting with all admitted endomorphisms. The same rule forbids coherent preparation and complementary readout across its sectors. For the elementary two-label model,
Thus preservation and interferometric manipulation cannot be capabilities of one closed operation algebra.
Typed repair
The minimal mathematical repair separates three morphism roles:
preparation object --preparation port--> selector object
selector object ----protected core----> selector object
selector object ----readout port------> observation object
Only the protected core lies in the commutant of (P). The ports may cross the selector decomposition, but their authority does not extend to arbitrary internal control. This is compositional typing, not chronology.
The magnetic frontier is consequently a source-derived packet declaring the protected core, both port boundaries, and their legal composites. A projector alone is inert; unrestricted off-diagonal control destroys protection.
Evidence
research/strominger/a-superselection-label-protects-the-selector-by-forbidding-its-interferometer.md;research/strominger/checkers/selector_protection_manipulation_role_split_checks.py;research/strominger/results/selector_protection_manipulation_role_split_checks.json.
The exact checker passes 9 of 9 gates. Checker SHA-256:
3f1386bee844c56feb659f07048b0054f72d074f6870c0b127cc9fe22da66137.
Allocator claim: seqclaim-0bfea838191265f8b83b95da.