Observational Refinement of Vacuum Viscosity: Constraints from Fast Radio Burst Dispersion Measures

Abstract: 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. This research note presents a refined calculation of the vacuum viscosity parameter (η) within the framework of Primary Energy (PE) Theory. While initial phenomenological estimates suggested an upper bound of η ≤ 0.14, a new high-precision analysis of the extragalactic dispersion measure (DM) floor in localized Fast Radio Bursts (FRBs) constrains this parameter to a tighter range: η ≈ 0.10 ± 0.02. The observed linear floor slope (approx. 980-1000 units) exceeds the standard baryonic limit (approx. 850-900) by approximately 10-15%, providing direct observational evidence for a viscous vacuum contribution. Remarkably, this refined value (η ≈ 0.10) perfectly resolves the Hubble Tension ratio (H_late / H_early ≈ 1.10), suggesting a unified physical origin for both phenomena.