Regular N=27 Black Holes from the M_2(\mathbb C) Finite-Response Registry: Exact Geometry, Dynamical Flux Constraints, and a Preregistered Dimensionless Endpoint Fingerprint

This paper develops a regular (N=27) black-hole realization from the (M_2(\mathbb C)) finite-response registry of Natural Physics. The resulting geometry has a finite nonsingular core, an exact critical mass, and a unique surface-gravity turnover. Most importantly, it preregisters a parameter-free dimensionless endpoint fingerprint - including (M_{\rm crit}/m_{\rm P}=4.64687948), (M_T/M_{\rm crit}=1.28174587), and the full (\Theta(s)) curve—before relevant endpoint observations exist. The construction therefore supplies a concrete prospective test: future measurements inconsistent with any of the frozen invariants would falsify this (N=27) realization.