PSI-ARCHITECTURE: A Retention Criterion for Structural Stability From Cosmology to the Quark Boundary

This record presents a formal ψ-architecture for structural retention, based on three primitives: structural differentiation (Δψ), a retention parameter (Ξ), and an internal ordering variable (τ). A Lagrangian core is introduced together with a closed-form, dimensionless retention criterion that governs phase existence, criticality, and collapse. The architecture is subjected to explicit stability analysis and falsification constraints. To establish physical relevance without replacing established theories, an effective energy-density term is introduced as a minimal anchoring to cosmological dynamics. A unique diagnostic signature separates ψ from a pure cosmological constant: a nonzero modulation index and a fixed structural susceptibility, yielding a quantitative prediction as a logarithmic deviation from ΛCDM at the 10⁻³–10⁻² level and a signed shift in the growth index. The observational protocol is explicit (RSD / BAO / supernovae). At the particle boundary, ψ is formulated as a pre-dynamical phase-admissibility constraint compatible with QCD. The architecture does not modify gauge dynamics or particle content and introduces no new interaction. It tests whether persistent differentiation requires retention as a structural condition. The model is falsifiable by construction.