Paper B: The Universal Coupling Unit and Branched Flow

We present Branch B of the Ontology of Irreducible Execution: an alternative implementation of the protective belt that replaces the CTMC over a random graph with two complementary mechanisms — the Universal Coupling Unit (UCU) as a minimal binary operator generating topology, and Branched Flow as the spontaneous architect of stable structures. The hard core (Axioms I–IV, including the XAI Verification Architecture) remains completely intact. Branch B generates four predictions that differ from those of Papers I–IV: (B-P1) dark matter density profile r−0.52 derived from the spectral dimension of the UCU graph in d=3; (B-P2) primordial power spectrum n_s^B derived from the branched flow exponent in the weak-percolation regime; (B-P3) Bell correlation bound SCHSH^B as the norm of the Berry-phase-weighted UCU adjacency operator; (B-P4) Mott track collapse rate proportional to local Landauer entropy. The competition between the gamma = 0.48 prediction of Papers I–IV and gamma_B = 0.52 of Branch B is the programme’s internal empirical discrimination mechanism. Keywords: alternative implementation, UCU, branched flow, Mott track, Lakatosian branch, competing predictions, XAI Protocol, alternative protective belt.