The Dark-Matter Dominance Threshold in CAT-12 Cosmology A Resonant Phase Reset Condition Derived from the Six Laws of the Cosmic Algorithm

The Dark-Matter Dominance Threshold in CAT-12 Cosmology presents a structural cosmological model in which the universe evolves toward a phase boundary defined by the relative dominance of dark matter over light-emitting baryonic structures. Within the Cosmic Algorithm Theory-12 (CAT-12) framework, this boundary is interpreted not as a terminal heat-death state, but as a harmonic threshold that triggers a phase reset into a new expansion epoch. Rather than proposing new particle species or replacing established physical theories, this work treats CAT-12 as a complementary structural framework that organizes known physical processes into a unified resonance-based cosmological interpretation. The model integrates: Stellar evolution and black-hole growth, Long-term cosmic star-formation decline, Thermodynamic entropy considerations, Dark-matter dominance at late cosmic times, into a single threshold condition derived from the six foundational CAT-12 laws. The paper develops: A formal definition of the dark-matter dominance threshold as a phase boundary. A structural interpretation of black holes as variability-reduction systems that drive matter toward invariant resonance states. A cyclic cosmological mechanism in which the dark-matter plateau functions as a phase-reset corridor rather than a terminal equilibrium. A five-stage cosmic phase cycle linking expansion, stellar evolution, dark-matter accumulation, threshold crossing, and renewal. The work is intentionally framed as a structural and phenomenological model rather than a replacement for general relativity, quantum mechanics, or standard cosmology. It builds upon observational results from Planck cosmology, stellar evolution theory, black-hole thermodynamics, and large-scale structure formation, reinterpreting them within the CAT-12 harmonic-resonance framework.