Photon-Induced Singularity: A Continuous-Accretion Model for Black Hole Cosmogenesis and Universal Expansion

We present the Photon-Induced Singularity (PIS) model, a cosmological framework in which the observable Universe constitutes the interior of a black hole formed within a larger parent universe. The model introduces three interconnected mechanisms absent from prior black hole cosmology proposals. First, the quantum state of the collapsing system at the moment of horizon formation — determined by the first infalling photon during the pre-closure window — sets the boundary conditions that encode the fundamental physical constants of the daughter spacetime. This resolves the fine-tuning problem through deterministic inheritance rather than stochastic mutation, and avoids causality violations by operating before causal disconnection is complete. Second, cosmic expansion is not the inertial remnant of a singular bounce, but a continuous process driven by the ongoing accretion of space-time by the parent black hole. This reframes dark energy as a dynamical quantity correlated with the parent black hole's accretion history. Third, the isotropy of expansion is explained through the well-established coordinate exchange in the Schwarzschild interior: the radial coordinate r becomes timelike past the horizon, removing any preferred spatial direction. We note that full three-dimensional isotropy additionally requires a near-spherical parent black hole, placing observational constraints on its angular momentum. Thermodynamic consistency is verified: the Bekenstein-Hawking entropy of the parent black hole (~10¹25 kB) exceeds the total observed entropy of the Universe (~10¹11 kB) by 14 orders of magnitude. We compare PIS with existing proposals (Pathria 1972; Smolin 1992; Poplawski 2010; Gaztañaga et al. 2025) and identify key open questions requiring formal mathematical treatment.