Λψ: Retentive Invariants Beyond Dynamical Cosmology Constraint-Based Stability, Non-Violation, and Post-Dynamic Persistence

This work introduces Λψ (Lambda-psi) as an effective retentive invariant describing the persistence of structure beyond active dynamical evolution. The framework addresses a foundational question left open by expansion-centered cosmology: why coherent structure can remain when dynamical drivers weaken or cease. Λψ is formulated as a constraint-based concept rather than a new physical field, force, or modification of gravity. The approach relies on minimal operational variables—retained difference (Δψ), retentive node (Ξ), and pseudo-time (τ)—and expresses stability through admissibility inequalities instead of evolution equations. The contribution is explicitly bounded and methodologically conservative. It does not replace existing cosmological models, nor does it claim empirical confirmation. Instead, it provides a formal language for post-dynamic stability, compatible with current frameworks and testable through indirect observational proxies based on persistence and absence-of-decay criteria. Ethical non-violation is embedded as a scientific constraint, defining admissible forms of observation and intervention. The framework is offered as a clarifying theoretical contribution, intended to support careful interpretation, comparison, and future empirical investigation.