Eridanus Supervoid

The Eridanus supervoid — a roughly 300 Mpc underdensity at redshift z ~ 0.2–0.3, spatially coincident with the CMB Cold Spot — is among the largest confirmed structures in the observable universe. ΛCDM's integrated Sachs-Wolfe effect predicts only a small fraction of the Cold Spot's observed temperature decrement even for a void of this size, leaving an unexplained residual. Successive Collision Theory resolves both the supervoid's existence and the Cold Spot alignment simultaneously. The Eridanus void is another collision pocket interior: a region swept clean of matter as the collision front compressed material into surrounding filaments and walls. Its size and underdensity depth are characteristic of a large collision pocket interior rather than a statistical fluctuation, placing it comfortably within SCT's expected void distribution.

The Cold Spot alignment with the Eridanus supervoid is physically direct in SCT. Photons traversing the supervoid experience a time-varying gravitational potential as they cross: because the void is embedded in a region where the effective cosmological term is locally enhanced, the potential is shallowing as the photon crosses rather than being static. This dynamic effect produces a net blueshift deficit — a cold signature — that exceeds the standard integrated Sachs-Wolfe prediction because SCT's dynamical Λ_eff is larger in the underdense region than ΛCDM's constant Λ predicts. The alignment is therefore not coincidental but causal: the same collision geometry that excavated the void also set up the enhanced local expansion rate that amplifies the Cold Spot temperature decrement, unifying the supervoid and the CMB anomaly into a single consistent explanation.