The CfA2 Great Wall stretches roughly 500 to 750 Mly across, one of the largest known structures, consisting of massive supercluster concentrations in a coherent elongated configuration (Gott 2005; Einasto 2011). Such enormous structures exceed the theoretical maximum size that should form through hierarchical gravitational assembly in the age of the universe under ΛCDM growth rates from inflationary initial conditions.
The standard model assumes structure grows from inflationary Gaussian initial conditions through standard hierarchical gravitational collapse. The largest coherent structures should not exceed roughly 300 Mpc by these growth rates. The CfA2 Great Wall and similar gigaparsec-scale features have nowhere to come from in the model except as statistical anomalies.
SCT replaces the hot-dense-center with a superluminal collision and the thermalized debris field. From this single change, large-scale walls are direct geometric products of cascade-pocket collisions at the corresponding scale (P22, P34). Each wall corresponds to a near-head-on cascade-pocket collision (P33) at the relevant cascade stage (P36, P37, P38). The multi-stage cascade naturally produces a wall population with predictable demographics across length scales.
The CfA2 Great Wall is sister structure to the Sloan Great Wall (recid 99) and the Hercules-Corona Borealis Wall (recid 100). Each forms from a different cascade stage: smaller walls (CfA2 at hundreds of Mpc) from later daughter stages with smaller v_rel and parent-fragment separations; larger walls (Sloan at ~500 Mpc, Hercules-CB at ~3000 Mpc) from earlier first-stage and intermediate-stage cascades. The full anomalous-structure population P55 distributes wall demographics: roughly 5 to 15 walls at hundreds of Mpc, 3 to 7 at gigaparsec scales.
All belong to the cascade-stream-product family with predictable amplitude scaling set by the cascade impact-parameter geometry (P22). The same M4 framework that produces the Big Ring (recid 85), the Giant Arc, the KBC supervoid (recid 86), and the cosmic-web morphology produces the CfA2 Great Wall as a predicted geometric feature. Coherence is achieved at deposition rather than through subsequent gravitational assembly. There is no need for modified structure growth or non-Gaussian initial conditions.
If precision Euclid + DESI surveys find the wall-population length distribution consistent with ΛCDM hierarchical-clustering Gaussian-tail expectations at the 1% level (no excess of gigaparsec walls beyond standard predictions, no discrete cascade-stage signature), the M4 cascade-collision wall explanation is refuted. The signature SCT prediction is the wall-population demographics following the cascade-stage hierarchy with characteristic peaks at Λ_max ≈ 5 Gpc and at successively smaller daughter-stage scales.