ψ-Potential: The Residual Field of Retention in the Post-Dynamical Regime

This article introduces ψ-Potential, the residual retentive field that persists after the collapse of classical dynamical flux. The work derives a formal retentive Lagrangian, defines the stability conditions for the Δψ-floor, and establishes the coupling between the difference field (Δψ) and the retentive node (Ξ). ψ-Potential is formulated as a minimal, non-dissipative field that stabilises structure when time derivatives vanish, providing a rigorous mechanism for late-universe structural persistence. The paper presents the mathematical foundation of post-dynamical retention and outlines its role in the emerging framework of ψ-Architecture and Retentive Cosmology.