TVCF: Non-Equilibrium Vacuum Dynamics, Dark Energy, and Non-Local Gravitational Phenomenology

This work presents the core formulation of the Time-Varying Cosmological Framework (TVCF), an effective description of cosmology in which the vacuum is treated as a non-equilibrium dynamical system with memory and non-local response. The framework provides a unified physical description of dark energy and dark matter phenomenology. Temporal relaxation of the vacuum generates a dynamical dark energy component responsible for late-time cosmic acceleration, while spatial non-local response to baryonic matter produces modified gravitational dynamics at galactic scales. The resulting theory reproduces observed rotation curves without invoking particle dark matter and predicts distinctive observational signatures, including structural dependence in gravitational lensing and deviations in structure growth. The framework is formulated at the level of an effective theory and defines a structured program for further theoretical and observational development. The inflationary sector of the framework is developed separately in a companion preprint.