The Hubble Tension as Exponential Vacuum Relaxation

The Hubble tension represents an observable non-equilibrium relaxation lag within a structured cosmic vacuum rather than an irreconcilable conflict between local distance-ladder measurements and early-universe cosmological surveys. Two Distinct Expansion Regimes: Local astronomical anchors sample the undamped, inviscid expansion occurring inside coherent vacuum domains, whereas deep cosmic microwave background and acoustic surveys measure the viscously damped rate averaged across an ensemble of domain boundary interfaces. Zeta-Fixed Tension Amplitude: The height of the expansion discrepancy is locked by the regularized boundary residue of the truncated normal-vector vacuum mode spectrum. This establishes an exact damping factor of one-twelfth, reducing the local baseline of approximately seventy-three kilometers per second per megaparsec to a global rate near sixty-seven kilometers per second per megaparsec without free parameters. First-Order Relaxation Dynamics: The discrepancy follows a first-order relaxation law where the initial structural lag decays exponentially across cosmic time. The early universe retains the unrelaxed lag observed in sound-horizon calibrations, while the late universe relaxes toward its macroscopic fluid limit. Scale-Dependent Expansion Profile: The model dictates that the inferred expansion rate declines smoothly and monotonically with lookback time over a characteristic relaxation timescale of roughly five billion years, providing a direct observational distinction from step-offset systematic errors. Origin of Metric Breakdown: Standard homogeneous cosmology fails because it forces an instantaneous response through a single scale factor, creating an apparent tension by overlooking the finite physical response time of the underlying vacuum medium.