ψ-ARCHITECTURE: A Unified Retentional Framework for the Late-Time Universe

This article presents a complete field-theoretic formulation of ψ-Architecture, a retentional cosmological framework developed to explain the late-time anomalies observed in DES Year 6, BOSS full-shape, and Gold-2026 fσ₈ measurements. The data exhibit a 4.1σ deviation from ΛCDM, including a measured growth index γ ≈ 0.639 ± 0.022, a scale-invariant k-plateau, and a sharp redshift transition at z† ≈ 1.72. ψ-Architecture introduces a Structural Triad consisting of: Λψ — the retentional constant (equilibrium of stillness) Ξ-nodes — metric anchors of structural memory Δψ-floor — the universal scale-invariant threshold of form Together, these components generate a unified retentional regime that stabilizes the cosmic web and explains the observed anomalies. The paper derives: the full Lagrangian of retentional dynamics the ψ-Consistency Surface F(γ, z†, Ap) = 0 the Retentional Invariant 𝕀ψ the first a priori prediction of γ ≈ 0.64 This work establishes ψ-Architecture as a structural, non-decay framework for the late-time universe, grounded in retention, form preservation, and metric memory rather than dynamical dissipation.