V.D299 — High-z Acceleration Enhancement

Enhancement factor E(z) = a₀(z)/a₀(0) = H(z)/H₀ ≈ Ω_m^(1/2)·(1+z)^(3/2). At z=10: E≈20.5, z=13: E≈29.4. τ-effective: uses established V.T204 + standard Friedmann.