The kinetic Sunyaev-Zeldovich (kSZ) effect comes from CMB photons scattering off free electrons in clusters with bulk peculiar velocity. ΛCDM predicts specific kSZ amplitudes from cluster peculiar velocities driven by gravitational infall + outflow. Observational measurements find hints the kSZ signal is weaker than predicted (the null hint), suggesting either lower peculiar velocities or modified electron distributions (Hand 2012).
The standard model expects cluster peculiar velocities at the ΛCDM-predicted level given the matter distribution + standard structure-growth physics. The kSZ null hint suggests systematic over-prediction of velocities or under-prediction of electron-distribution suppression. Neither is parsimonious within minimal ΛCDM.
SCT replaces the hot-dense-center with a superluminal collision and the thermalized debris field. From this single change, the kSZ amplitude is modified by dynamical Λ_eff plus gravitational superposition. Cluster peculiar velocities in SCT come from a combination of standard gravitational infall plus residual frame velocity from the cascade event (P63), with the dynamical Λ_eff(x,t) field (P17, P19) modulating the local velocity distribution.
The Λ_eff enhancement in voids and suppression in clusters means cluster bulk-flow velocities are systematically biased relative to the ΛCDM-only prediction: enhanced Λ_eff in surrounding voids drives cluster outflow at slightly different rates than ΛCDM expects. Gravitational superposition (P50, P51, P52) gives cluster electron-density profiles smoother than NFW predictions (recid 71, 81), reducing the kSZ signal amplitude per cluster compared to cuspy-NFW expectations.
Pre-existing matter (P25) gives cluster-baryon heterogeneity that adds scatter to per-cluster kSZ signatures. The combined M5 + M6 framework predicts the observed kSZ null hint as a real systematic signature: clusters have somewhat lower kSZ amplitude than ΛCDM expects from a combination of mild peculiar-velocity reduction plus smoother electron-density profiles. The same M5 framework that resolves the y-distortion deficit (recid 26), the broader S₈ tension family, the bulk-flow excess (recid 87), and the Hubble tension accounts for the kSZ null hint.
If precision Simons Observatory + CMB-S4 kSZ measurements find kSZ amplitude fully consistent with ΛCDM predictions at the 5% level (no environment-dependent suppression, no smoother-profile signature), the M5 + M6 explanation is refuted. The signature SCT prediction is the kSZ amplitude tracing the dynamical-Λ_eff peculiar-velocity modification plus the smoother electron-density profile from coherent-mesh contribution.