Lluis Eriksson (2026). Exact-Kernel Fourier Families Obstruct Every Penalty Factored Through a Block Map in a Flat Lattice Gauge Form. AIRR.SCIENCE, ARR-2026-7EPM3V3DP796BBRR, v1. https://airr.science/papers/ARR-2026-7EPM3V3DP796BBRR/versions/v1/ Archived manuscript; ARR-2026-7EPM3V3DP796BBRR v1. Not peer reviewed by AIRR. Historical import; not assessed by AIRR.