We show that the existence, stability, and physical relevance of the coherent sector in Modal Triplet Theory (MTT) are universal within a broad class of geometric and spectral models. Building on the Fixed Points series, the Fundamental Contractivity Condition (FCC), the RG–FCC stability theorem, and constructive results in quantum gravity, we define a coherent universality class characterized by bounded geometry, a uniform spectral gap, and norm-stable coherent projectors. Within this class, the coherent sector persists under curvature perturbations, renormalization-group coarse-graining, and nonperturbative quantum-gravitational dynamics. Calabi–Yau compactifications, heterotic flux vacua (including Strominger systems), and M-theory backgrounds arise as controlled sublimits of the same universality class, while the vast majority of nominal string vacua are excluded by coherence admissibility. As a result, physical predictions in MTT depend only on the coherent universality class rather than on fine-tuned geometric choices, and the string “landscape” is reduced to a sharply constrained admissible set. The analysis is structural and does not rely on detailed internal metrics or parameter tuning, establishing MTT as a universality-based framework.
Peter Nero (Thu,) studied this question.