Resolution of the Hubble Tension via Vacuum Viscosity: A Variable Speed of Light Model

Notice: This document represents an early-stage conceptual draft. It has been deposited in this archive primarily to establish academic priority for the core physical hypotheses and experimental proposals (e.g., the local energy density framework). Readers should be aware that the mathematical formalism and numerical calculations herein are preliminary and are currently undergoing rigorous refinement. For the fully calibrated and peer-reviewed mathematical framework regarding the cosmological applications of this theory, please refer to the latest publications of the Primary Energy Research Group. The discrepancy between the Hubble constant (H₀) measurements from the early Universe (CMB) and the late Universe (Supernovae Type Ia) has reached a statistical significance of 4–6σ, creating a crisis known as the "Hubble Tension." The standard ΛCDM model fails to resolve this without introducing exotic physics. In this paper, we propose a solution based on the hypothesis of a physical vacuum possessing non-zero viscosity (η). We introduce a viscosity coefficient η ≈ 0.14, initially derived from anomalies in muon decay times and photometric analysis of high-redshift galaxies, and subsequently confirmed by the dispersion analysis of gravitational wave event GW150914. We demonstrate that in a viscous medium, the effective speed of light (c) depends on the local energy density. By correcting for the difference between the absolute speed of light in cosmic voids (c_abs) and the observed speed in dense galactic clusters (c_obs), we show that the 9–10% Hubble tension is an artifact of assuming a constant speed of light. The proposed model reconciles the datasets without requiring Dark Energy.