Fourier--Tate Reflection Reverses Drift, Not Forcing Variance
The actual centered theta equations use the same real forward forcing on both reciprocal sheets:
Fourier--Tate reflection reverses spectral drift but transports the
upper-right source-to-tail arrow to another upper-right arrow. It does not
produce the lower-left adjoint incidence B*.
Therefore the same-forcing pointwise common-path no-go applies to the native theta double, closing the reflected-forward Green shortcut. With a role-preserving pairing, cross-adjointness of two nontrivial upper-triangular forward blocks is impossible: it forces the source incidence to vanish.
The unique surviving local constructor is variance-reversing adjoint
completion. At finite cutoff it must supply a typed lower incidence
B_{-,X}:H_X -> U_X and pass
with domains, metrics, and boundary grades retained. Scalar agreement after aggregation is insufficient.
Research packet:
research/grothendieck/fourier-tate-reflection-reverses-drift-not-forcing-variance.md
Exact checker:
research/grothendieck/checkers/check_reflection_does_not_reverse_forcing_variance.py
The checker passes 6/6 exact tests.