Breaking the Degeneracy of Dark Energy: A Strict Two-Step Calibration of Continuum Field Entropy (CFE) Vacuum Field Impedance using Pantheon+ Cepheids

**Preprint | Continuum Field Entropy Empirical Validation Series** Standard ΛCDM cosmology interprets the dimming of high-redshift Type Ia Supernovae as evidence for Evolving Dark Energy. The Continuum Field Entropy (CFE) framework alternatively postulates that the universe is a shear-thickening Cosserat continuum, where geometric expansion is strictly matter-dominated and optical dimming is a thermodynamic consequence of Amplitude Vacuum Field Drag (ΓFlux). Previous tests demonstrated that both the Cosmic Microwave Background (CMB) plasma and deep-space supernovae exhibit a fractional vacuum field impedance of ≈ 0.721. However, unconstrained Bayesian analyses suffer from mathematical degeneracy between a supernova’s Absolute Magnitude (M) and vacuum field drag. In this paper, we execute a strict two-step anchoring pipeline using the Pantheon+ dataset. Step 1 isolates 77 local Cepheid-calibrated supernovae ($z < 0.01$)—where CFE optical depth is mathematically negligible—to permanently lock the absolute baseline luminosity at M = -19.2600 ± 0.0390. Step 2 applies this frozen baseline to 1,513 deep-space supernovae, forcing the algorithm to attribute all high-redshift dimming to vacuum field friction. The analysis yields ΓFlux = 0.6871 ± 0.0225, closely approximating the universal $0.721$ primordial saturation limit within 1.5σ error bounds. Furthermore, subjecting the dynamic CFE relaxation integral to the full 1701 × 1701 systematic covariance matrix seamlessly recovers the universally accepted local expansion baseline (H₀ ≈ 72.92 km s⁻¹ Mpc⁻¹), establishing a causally unbroken mechanical timeline of entropic vacuum field relaxation that renders Dark Energy obsolete. **Project Integration:**This document is a standalone validation report. The underlying universal field equations, foundational axioms, and the complete multi-disciplinary validation framework can be found in the primary master manuscript (DOI: 10.5281/zenodo.20631794).