The Oxidative Niche Transition: Abiotic Oxygen as a Closure Constraint Layer

This paper formalizes the Oxidative Niche Transition: a structural constraint-layer shift in which localized abiotic oxygen production expands the admissible closure space of chemical networks. Within the ψ₀–OCM (Osborne Cosmological Model), oxidative niches function as localized microenvironments that enable oxygen-mediated pathways prior to global oxygenation. The work provides a cross-scale bridge linking geochemistry, prebiotic chemistry, metabolic energetics, and planetary oxygen stabilization through a unified admissibility framework.