ψ-Retention Cosmology: Λψ — Filming Beyond Disappearance and the Geometry of Care .ψ-Retention Cosmology — Λψ

This paper introduces ψ-Retention Cosmology, proposing a retentional term Λψ as an ontologically distinct contribution to late-time cosmology. Building on the ψ-architecture framework (ψ-Silence; ψ-Potential), I show that when the time derivative of internal difference (Δψ) vanishes locally while a structural retention node (Ξ) remains finite, the system enters a post-dynamical regime in which energy persists as form rather than flux. Λψ parameterizes this finite, non-dissipative energy of retention and supplements the standard Friedmann dynamics without contradicting ΛCDM background expansion. Methodologically, the paper formulates a minimal retentional Lagrangian Lψ(Δψ, Ξ) with a convex retention potential V(Δψ, Ξ) = αΔψ² − βΞΔψ + γΞ² and introduces Λ(Ξ) coupling terms that connect retention to global topology. I derive stationary solutions, outline a compact simulation prototype demonstrating convergence to retentional fixed points, and map laboratory analogues (optical/acoustic quenched interferometers) that reproduce “plateau” signatures of retained correlation. Empirically testable predictions are given: (i) correlation-time plateaus in large-scale two-point functions exceeding ΛCDM forecasts at the largest scales; (ii) suppressed temporal drift in low-frequency relic backgrounds (“stilled heat”); (iii) persistent homology plateaus in topological analyses of the cosmic web. A practical parameterization for survey fits (wψ(a) ≈ −1 + ε(a)) is proposed, with forecast detection thresholds for Stage-IV lensing + DESI. Beyond physics, the work advances an ethical principle — non-violation — formalised as an observational constraint: measurement must not accelerate decay of retention. ψ-Retention Cosmology therefore unites theoretical cosmology, experimental reproducibility, topology, and an ethics of observation, offering a cross-disciplinary programme that is immediately relevant to cosmologists, philosophers of science, data curators, and art–science institutions. Theoretical Cosmology; Philosophy of Physics; Metaphysics of Science; Structure Formation; Topological Data Analysis; Ethics of Science; Experimental Reproducibility; Visual Philosophy / Art–Science.