Projection, Probability, and Irreversibility in Modal Triplet Theory

We present a unified framework connecting quantum measurement collapse, black hole information loss, and the origin of probability in cosmology within Modal Triplet Theory (MTT). In this framework, effective four-dimensional physics arises as a shadow of deterministic dynamics on a higher configuration space under a generally noninvertible coherent projection. We define admissibility barriers—loci where this projection fails to be stably invertible due to spectral gap closure, projector discontinuity, or basin rearrangement—and prove that crossing such barriers necessarily destroys global reconstructability of the induced four-dimensional dynamics. Quantum measurement collapse and black hole information loss are shown to be distinct physical realizations of this same mechanism. We further show that Born probabilities, Hawking thermal weights, and cosmological initial-condition measures arise from a single basin-measure functional evaluated across different admissibility barriers within the coherent universality class. Inflationary attractors, decoherence, POVM updates, and island constructions are identified as partial shadows that detect basin structure but cannot restore global invertibility. Finally, results on computational irreducibility imply that information loss across some admissibility barriers is principled rather than merely practical.