Baryonic Back-Reaction and the Late-Time Growth Plateau (γ ≈ 0.63)

This video presents a concise overview of the January 2026 analysis showing that baryonic back-reaction cannot account for the observed late-time growth plateau γ ≈ 0.63. Drawing on Euclid SC8, DESI DR2, X-ray and SZ gas-fraction constraints, and state-of-the-art numerical simulations, it explains why baryonic feedback—although essential at small scales—lacks the magnitude, scale-independence, and redshift invariance required to reproduce the plateau. The results highlight the need for a structural, non-baryonic mechanism governing late-time cosmic growth.