SEEDZ Simulations Link Rapid Halo Accretion to Heavy Black Hole Seeds via Sustained Central Inflows

SEEDZ tracks early galaxy assembly in a cosmological volume with a heavy-seed threshold of >1 M⊙ yr⁻¹ into 10 pc. Halos meeting this criterion exhibit faster mass growth than non-seed halos, preserving high central densities out to 10–100 pc even after stellar feedback begins. Most seeds at z=10 form near solar metallicity, though a subset persists in 10^{-2} Z⊙ gas. The model predicts an SMS number density of 0.1 cMpc^{-3} under the assumption that only low-metallicity objects accreting above 0.02 M⊙ yr^{-1} for 2 Myr become SMS progenitors.

This channel bridges three fronts: the rapid-assembly bias seen in JWST high-z massive galaxies, the dense-cluster environments required for runaway stellar collisions, and the metal-poor pockets still available at z>10. Unlike static direct-collapse scenarios, SEEDZ shows seeds emerge dynamically once halo growth exceeds a critical threshold, naturally producing the observed scatter in early black-hole occupation fractions.

A key limitation remains the sub-grid treatment of angular-momentum transport inside 10 pc; unresolved torques could reduce central inflows by factors of a few. Higher-resolution zoom simulations with explicit stellar dynamics and radiative transfer are required to test whether the reported 10^{-4} visibility fraction for Little Red Dots holds.

Next, cross-matching SEEDZ seed sites with mock JWST NIRCam photometry will yield falsifiable predictions for the redshift and luminosity distribution of accreting SMSs, directly testable with Cycle 3–4 deep fields.