Thermal SZ power spectrum from Planck, ACT, SPT consistently shows lower amplitude than ΛCDM predicts from primary CMB σ₈ (A_tSZ ≈ 0.3-0.5 vs expected 1.0). Deficit pronounced at high multipoles l > 2000 (Planck 2016; Bolliet 2025). Implies lower σ₈ (worsens S₈ tension), hot-gas deficit in lower-mass halos, or stronger AGN feedback ejecting baryons, none of which is parsimonious.
The standard model expects tSZ amplitude consistent with cluster pressure-profile predictions from CDM-halo + standard-gas physics. Recovering the observed deficit demands fine-tuned feedback or modified gas physics, none of which is parsimonious without external constraints.
SCT replaces the hot-dense-center with a superluminal collision and the thermalized debris field. From this single change, the tSZ power spectrum amplitude is modified by gravitational superposition. Per Paper 6 (recid 16, 30 framework): C_l^tSZ(SCT) = A^(-7/3) C_l^tSZ(ΛCDM) where A is the cascade-mesh amplification factor (P50, P51, P52, P54).
For typical cluster A ≈ 1.10 to 1.20, this gives a tSZ-power suppression of order A^(-7/3) ≈ 0.7 to 0.8 relative to ΛCDM, naturally producing the observed amplitude deficit at high multipoles. The cascade-mesh contribution gives smoother cluster pressure profiles than NFW expectations, reducing the high-l tSZ power without invoking enhanced feedback or hot-gas deficit. The underlying cluster gas content remains consistent with observations; only the tSZ amplitude is modified by the smoother profile.
Cascade-thermalized + plasma-equivalence initial conditions (P22, P23, P29, P30) supply the cluster-progenitor thermodynamic state. Pre-existing matter (P25) gives cluster-baryon heterogeneity. The same M6 framework that resolves the broader S₈ tension family, the cluster-substructure GGSL excess (recid 194), the c-M relation flatness (recid 195), and the broader no-DM-particle phenomenology accounts for the tSZ power deficit as a coherent-mesh-suppression signature.
If precision Simons Observatory + CMB-S4 tSZ measurements find amplitude fully consistent with ΛCDM CDM-halo + standard-gas-physics predictions at the 5% level (no cascade-mesh A^(-7/3) suppression signature), the M6 explanation is refuted. The signature SCT prediction is the tSZ amplitude scaling consistent with the calibrated A factor.