Quasars at z > 7 host supermassive black holes (SMBHs) with masses 10⁹ to 10¹⁰ M☉ (Wu 2015; Banados 2018). These SMBHs are too massive to have grown from stellar-mass seeds within the available cosmic time, even at the maximum Eddington-limited accretion rate. There is simply not enough time between the Big Bang and z = 7 for stellar-remnant black holes to have gained 10⁹ solar masses through standard accretion physics.
The standard model assumes all SMBHs grow from stellar-mass seeds (M ~ 10 to 100 M☉) via Eddington-limited accretion over cosmic history. Reaching 10⁹ M☉ by z = 7 requires either super-Eddington accretion (which violates standard radiative-pressure constraints) or exotic "heavy seed" direct-collapse scenarios that themselves require fine-tuned conditions to operate.
SCT replaces the imaginary hot-dense-center with a superluminal collision and the thermalized debris field that became our visible universe. The cascade of multi-stage thermalization that followed the initial collision did not perfectly homogenize all of the matter into a smooth photon-baryon plasma. Approximately 99% of the matter cascaded through the QCD-scale thermalization process and ended up as the standard plasma that produced the CMB, BBN, and ordinary structure formation. A small fraction (the densest, most overdense leftover regions) did not fully thermalize. Instead, those overdense seeds collapsed directly into compact objects during or immediately after the cascade.
These cascade-seeded compact objects are the direct ancestors of the early SMBHs we now see at z > 7. With initial masses of approximately 10³ to 10⁵ M☉ (paper 4208, P39 alternative version), they are several orders of magnitude more massive than stellar remnants and therefore need only a few hundred million years of standard Eddington-limited accretion to reach the observed 10⁹ to 10¹⁰ M☉ range by z ≈ 7. There is no "not enough time" problem in SCT because the SMBH precursors did not have to be built from stellar remnants. They were already substantial at the cascade epoch.
This is one of the cleanest examples of how the toggle from hot-dense-center to superluminal-collision-and-thermalized-debris-field works in practice. ΛCDM cannot easily produce 10³ to 10⁵ M☉ seeds because its hot-dense-center origin starts with a smooth uniform plasma that gives no natural mechanism for direct-collapse SMBH precursors. SCT's collision-cascade origin naturally leaves behind a spectrum of leftover overdense regions, of which the densest collapse directly. The early SMBHs are not anomalies in SCT; they are the visible signatures of the cascade-seeded compact-object population that SCT predicts.
The same mechanism handles the JWST observations of overmassive BHs at z ~ 10 (UHZ1, GN-z11, etc.) and the BH-to-stellar-mass ratios 10 to 1000 times above the local Magorrian relation that JWST has revealed. None of these requires super-Eddington accretion or exotic seeding mechanisms in SCT. They are the natural consequences of cascade-seeded compact-object formation.
If a complete census of z > 7 SMBHs is shown to be fully consistent with growth from stellar-mass seeds via Eddington-limited accretion (with no residual population requiring direct-collapse heavy seeds), the cascade-seeded compact-object mechanism is refuted. JWST + ELT + Roman observations across z = 6 to 15 will provide the relevant precision in the next decade.