APF Paper 4 — Admissibility Constraints and Structural Saturation

Admissibility Physics — Constraints, Saturation, and Structural Boundaries (Paper 4) This Zenodo community collects research outputs associated with Admissibility Physics, with primary focus on Paper 4 — Admissibility Constraints and Structural Saturation and the universal feasibility boundaries implied by finite enforceability. Paper 4 characterizes the constraint layer of the framework: the structural exclusions that hold independently of dynamics, probability, or geometric representation. Building on finite enforceability (Paper 1), non-closure under composition (Paper 2), and ledger accounting of committed capacity (Paper 3), it shows that many familiar physical limits arise as feasibility boundaries, not as dynamical effects. The paper derives monogamy of correlations, cut-set bounds, and area-law scaling as direct consequences of finite interface capacity. It introduces saturation as a sharp structural condition—where remaining enforceable correlation capacity is exhausted—and shows that beyond this boundary no admissible continuation exists without releasing previously enforced distinctions. Saturation produces statistically sharp knees rather than smooth transitions and explains the emergence of horizons, Page-like transitions, and measurement-like events as capacity-exhaustion phenomena. Crucially, these results do not depend on quantum mechanics, spacetime geometry, or equations of motion. They apply wherever correlations must be jointly enforced under finite capacity. Dynamics, probability, and geometry are shown to be secondary representations that fail at saturation boundaries, while admissibility accounting remains well-defined. All subsequent works in this community rely on the constraint structure established in Paper 4. Later papers show how quantum description, variational dynamics, and geometric representation operate only within unsaturated regimes, and how their breakdowns correspond to genuine structural limits rather than pathologies. This community serves as a curated, citable archive centered on the constraint and saturation layer of Admissibility Physics. Paper 4 functions as the boundary-defining core of the program: the point at which abstract enforceability becomes concrete physical limits. Core papers are frozen where noted; companion papers, mathematical supplements, figures, and computational artifacts document derivations, regime conditions, and observable signatures.