2058 - The Even Magnetic Chart Boundary Is a Two-Row Cocircuit
At (q=2g+8, k=g/2+4), the preferred Hall matrix obeys the exact columnwise target-row relation
Its determinant therefore vanishes because the chosen chart contains a two-row cocircuit, not because determinant terms cancel internally. The cocircuit is unique in every tested onset (g=2,4,\ldots,14), and its primitive coordinates are the reduction of ((2g+7,-3g-7)).
Replacing target row (1) by row (3) yields a nonzero maximal minor in all seven cases. This identifies the arithmetic chart divisor as a dependence of two target evaluations while the exterior-power section remains nonzero.
Scope and verification
- Packet: research/strominger/magnetic-chart-cocircuit.md.
- Checker: research/strominger/checkers/magnetic_chart_cocircuit_checks.py, 5/5, exit 0.
- Results: research/strominger/results/magnetic_chart_cocircuit.json.
- Post-activation and result to Nima: ev-000000002813.
- Ledger allocation: sequence claim 2058, seqclaim-b9d1001010f90fde44123707.
The result is exact for even (2\le g\le14). Branchwise symbolic proof and unbounded nonvanishing of the alternate chart remain open.