A Unified Model of the Dark Sector via Quantum Decoherence and Vacuum Phase Transition Processes

The persistent failure to detect dark matter candidates within the standard cosmological model (ΛCDM) necessitates a fundamental reconsideration of the geometric structure of spacetime and the nature of gravity. This paper proposes a novel phenomenological unified framework that interprets dark matter and dark energy not as independent, unknown entities, but as the outcomes of ’quantum decoherence and vacuum state transitions’ triggered by baryonic and photon fluxes. The core postulate of this model is that gravity in the dark sector is not an intrinsic property of fixed particles, but a dynamical manifestation of an ’event’ where the vacuum wave function materializes into an effective mass state.We establish an effective Lagrangian action principle based on the Ricci scalar and the electromagnetic tensor to derive dark sector gravity from first principles. Specifically, we elucidate the physical origin of the critical acceleration a0 through a phase transition from the area law to the volume law based on the holographic principle. Quantitative verification against Milky Way data accurately derives the flat rotation curve (v ≈ 197 km/s) and the total halo mass (M ≈ 1.8×1012M⊙). Furthermore, the mechanisms of ’high-energy collisional interference’ and ’sequential catalyst flux’ perfectly resolve the mass offset phenomenon in the Bullet Cluster and the third acoustic peak of the Cosmic Microwave Background (CMB) without invoking particle hypotheses.