The Clausius-Mossotti (CM) metric ds² = W^ (1/3) c²dt² − W^ (−1/3) (dr²+r²dΩ²) satisfies gₜt × gᵣr = 1 identically and reproduces all six classical tests of GR. This paper derives a CM-specific growth equation for cosmological density perturbations: δ̈ + 2H·W₀^ (1/6) ·δ̇ = 4πGρ̄δ·W₀^ (1/3), where W₀ = Ωₘ (z). The modifications arise from the metric's time dilation, not from a change in gravitational coupling. At linear order, CM = GR (from gₜt×gᵣr=1). The equation passes six observational tests: matter-era consistency (exact), S₈ vs DES (0. 52σ), fσ₈ vs RSD (χ²/N=1. 14), H (z) vs chronometers (χ²/N=0. 45), BAO vs DESI DR1 (χ²/N=1. 51, CM preferred over ΛCDM), and cosmic age (0. 48σ). Growth index prediction: γ = 0. 607 ± 0. 010 (vs GR 0. 549), testable by Euclid at 2. 9σ. All three tensions (H₀, S₈, Ωₘ) traced to one cause: ΛCDM Ωₘ = 0. 315 too high. CM derives Ωₘ = (1−p) ² = 0. 2784 (p = e^ (−3/4), zero fitted parameters), reducing total tension² by 89%. Code: https: //github. com/singhmandy25-gif/speed-gap-framework/tree/main/cm-perturbation-theory
Mandeep Singh (Sun,) studied this question.