Decoherence in Einstein Gravity: Unifying Quantum and Spacetime

We propose a unified framework where spacetime curvature regulates the decoherence of the quantum vacuum state, naturally giving rise to gravity, classical spacetime, and quantum probabilities (the Born rule). Using a logistic curvature filter, derived from local curvature invariants, our model emerges from general relativity and quantum field theory without new fields or modified actions. It significantly reduces the fine-tuning required for the cosmological constant problem, eliminates black hole and cosmological singularities, explains cosmic acceleration, and derives the Born rule dynamically. Testable predictions include a coherence collapse in the cosmic microwave background at multipoles ~ 4000, supported by Planck data, and polarization decoherence near black holes, consistent with M87* observations. This minimal, observationally grounded approach offers a predictive path to unify quantum mechanics, gravity, and classicality, accessible to near-future experiments. v2: Minor updates to phrasing based on feedback.