Large Quasar Groups (LQGs) are enormous concentrations of quasars spanning 300 to 600 Mly or more, with the Huge-LQG stretching ~4 Gly across containing 73 quasars (Clowes 2012; Lietzen 2011). The probability of randomly finding so many quasars within such enormous projected structures is extremely low under ΛCDM assumptions about quasar clustering and the homogeneity of the universe.
The standard model assumes quasars cluster at the level of standard galaxy clustering, with the cosmological-principle-imposed homogeneity at scales above roughly 300 Mpc. Coherent quasar groups at gigaparsec scales violate the cosmological principle and exceed standard clustering expectations by orders of magnitude. The model has no source for such coherent rare-object distributions.
SCT replaces the hot-dense-center with a superluminal collision and the thermalized debris field. From this single change, the Huge-LQG and similar large quasar groups are direct cascade-stream signatures (P22, P34, P55). The cascade impact-parameter distribution P(b) ∝ b deposits cosmic-web filaments at scales up to Λ_max ≈ 5 Gpc; quasars (which require pre-existing SMBH seeds plus active accretion) preferentially form along these cascade-stream filaments where the gas density is enhanced.
Pre-existing SMBH seeds inherited from prior cascade cycles (P25) are placed throughout the cascade-stream filament network, supplemented by cascade-direct-collapse SMBH formation (P46) at high-density cascade nodes. Quasar activity then turns on preferentially in cascade-stream-aligned configurations, producing the observed gigaparsec coherent groupings. The same cosmic-web infrastructure that produces the Sloan Great Wall (recid 99), the Hercules-Corona Borealis Wall (recid 100), and the Big Ring (recid 85) carries the Huge-LQG quasar population.
Angular-momentum inheritance (P31, P32) gives quasar-axis alignment matching the cascade-stream J vectors, producing the observed quasar polarization 1 Gpc coherence (cross-link). Multi-stage cascade dynamics (P36) sets the formation epoch where quasar activity peaks at the cosmic-noon era. The same M4 + M11 framework that produces the cosmic-web morphology and the gigaparsec anomalous-structure population produces the LQG observation. There is no need to abandon the cosmological principle or to invoke modified quasar clustering physics.
If precision LSST + Euclid + Roman quasar surveys find quasar clustering consistent with standard galaxy-clustering predictions at the 1% level above 300 Mpc (no excess gigaparsec-scale coherent quasar groups beyond statistical fluctuation), the M4 cascade-stream LQG origin is refuted. The signature SCT prediction is quasar coherence at gigaparsec scales matching the cascade-stream-filament demographics.