Unified Spacetime Dynamics in the R5+ Framework: From Galactic Kinematics to Black Hole Thermodynamics and Quantum Entanglement

At cosmological scales, the model’s inherent phase transitionreproduces the acoustic peaks of the Cosmic Microwave Background (CMB) by mimicking late-forming dark matter. Furthermore, we show that in the ultra-high-densitylimit, this coupling prevents the formation of spacetime singularities. It predicts theexistence of horizonless compact objects, analogous to Gravastars (Gravitational Vacuum Stars), sustained by the false vacuum pressure of the Symmetron field. We alsoexplore the ultraviolet (UV) deductions of the model, specifically demonstrating howSymmetron screening preserves the speed of gravitational waves in dense environments, satisfying multi-messenger constraints Keywords Modified Gravity, General Relativity Extension, Symmetron Field, Proca Field, Fluid Geometry, Galactic Dynamics, Astrophysics, Theoretical Physics, Open Science