Around M31, roughly half of the known dwarf satellites lie in an extremely thin plane (1:10 aspect ratio) hundreds of kpc wide, with many sharing a common rotation sense forming a vast co-rotating satellite disk (Ibata 2013; Conn 2013; Pawlowski 2018; Santos-Santos 2023). Together with the Milky Way's VPOS (recid 130), the joint occurrence is exceedingly rare under ΛCDM (joint probability around 0.001%).
The standard model assumes M31 satellites accrete stochastically from a roughly isotropic CDM-substructure population, predicting roughly spherical satellite distributions with only mild anisotropy. The thin co-rotating M31 plane mirroring the MW VPOS demands either filamentary infall coincidence ruled out by simulations or a fundamental modification of the satellite-accretion model.
SCT replaces the hot-dense-center with a superluminal collision and the thermalized debris field. From this single change, the M31 satellite plane is the same shared-cascade-J inheritance signature as the MW VPOS (recid 130). M31 inherits J from its own cascade-stream parent event, distinct from MW's parent event but within the same broader Local Group cascade-cosmic-web context (P22, P25, P31, P32, P34).
M31's satellite system formed together with M31 from cascade-debris siblings of the same parent event, all inheriting the same parent J vector. The satellites co-rotate by construction and form a thin plane set by the cascade impact-parameter geometry. The lopsidedness of the M31 plane toward the Milky Way reflects the Local Group cosmic-web cascade-stream geometry: M31 and MW are themselves siblings in the broader Local Group cascade context, and their satellite planes inherit aligned subsidiary J components.
The joint probability of MW + M31 co-rotating planes is consistent with the shared parent geometry under SCT (a single cascade event in the Local Group region produces both hosts plus their satellite systems with related J inheritance). Universal SCT prediction: co-rotating satellite planes around all adequately sampled hosts. Sibling pockets (P58, P59, P60) extend the coherence to multi-Mpc Local Group scales. Gravitational superposition (P50, P52, P54) provides the apparent dynamical mass without invoking exotic CDM. The same M3 framework that produces the MW VPOS (recid 130), the CenA satellite plane, and the broader satellite-plane phenomenon accounts for M31.
If precision LSST + Roman + Euclid survey of M31's complete satellite census finds the plane consistent with random-orbital-pole expectations at the 1% level after improved selection-effect modeling, the M3 shared-cascade-J inheritance is refuted. The signature SCT prediction is universal occurrence of co-rotating satellite planes around all sampled hosts including M31.