Velocity and potential templates built from galaxy surveys should align with CMB maps identically in every direction, yet ISW and kSZ reconstructions show anisotropic amplitudes and directional mismatches that persist across tracers and methods (Ho 2009; Sherwin 2012; Keisler and Schmidt 2013). Isotropy is structural in ΛCDM, so the model can only blame the surveys.
The standard model assumes a statistically isotropic velocity field and one uniform potential-decay rate, so a single template should fit every patch of sky. There is no mechanism by which the ISW and kSZ sectors could carry genuine, different, predictable axes; any directional residual must be footprint or modeling error, dataset by dataset, indefinitely.
SCT predicts the template residuals are real and carry a specific two-axis anatomy. The kSZ sector inherits a bulk-flow component along our patch's residual frame velocity, the 369 km/s motion written into the CMB dipole, set by the collision impact parameter (P63). The ISW sector inherits a directional component along the Λ_eff gradient, dominated locally by the KBC supervoid axis where potential decay runs fastest (P17, P19). These are different physics with different directions, which is exactly why one isotropic template fails both sectors in different ways.
The geometry is the testable part. The frame velocity points along the impact parameter b, while the collision's angular momentum J = μ(b × v_rel) is perpendicular to it, so the kSZ bulk-flow axis and the J-correlated structure axes should stand roughly 90 degrees apart (P64), a registered cross-check requiring only existing data. Sibling pockets at gigaparsec separations add a smaller third term to both templates (P58, P59). The premise inventory is the same one already carrying the bulk-flow excess and the CMB dipole anomalies; the collision geometry is laid out in Paper 1, From Chaos to Convergent Foundations, and the expansion-side Λ_eff structure in Paper 7, From Chaos To Cosmic Expansion.
Nothing here is added for this tension. Two axes were deposited by one collision; the templates are simply the first instruments sensitive enough to notice both at once.
Simons Observatory and CMB-S4 directional reconstructions carry the kill: if the kSZ and ISW residuals are consistent with isotropy at the one-percent level, or if their axes coincide rather than standing roughly perpendicular, the two-axis collision geometry is refuted. SCT requires the kSZ axis near the CMB dipole direction and the ISW directional component along the Λ_eff gradient; one isotropic null or one shared axis breaks the anatomy.