Structural Retention Cosmology: A Paradigm for the γ≈0.63 Plateau

A carefully structured analysis situating the persistent late-time growth-rate plateau (γ ≈ 0.63) within the contemporary tripartite cosmological landscape of early 2026. The study compares three major explanatory frameworks—Dynamical Dark Energy, Modified Gravity, and Structural Retention Cosmology—without advocating for a single model. It synthesizes results from Euclid SC8, DESI DR2, ACT, and HSC-Y3, examining how each framework interprets suppressed structure growth and how retention-based approaches describe a “soft drift” regime of informational equilibrium. The work is intended as a neutral reference for researchers studying the structural origin of late-time growth suppression.