ψ⁰: Retention at Zero — Architecture of Difference Under Total Erasure

This paper introduces ψ⁰, a retentive architecture for persistence under the limit condition of total erasure (Z-state), where time, energy, coordinates, and observation cease to function as carriers of structure. The framework does not propose a physical model or empirical predictions. Instead, it formalizes an ontological condition of persistence based on irreducible difference (Δψ), autonomous anchoring (Ξ), a retentive condition (Λψ), and non-chronological ordering (τψ). Retention is treated not as force, energy, or expansion, but as a boundary regime in which structural coherence may remain possible when physical supports vanish. Dark energy is reinterpreted as a structural boundary property rather than as repulsive pressure, without replacing standard cosmology. The work positions ψ⁰ as a model of possibility rather than a cosmological model, isolating a single domain: persistence under annihilation. Version 2 (published separately) provides a stress-test and adversarial critique of the framework.