The Ouroboros Equation for Unified Physical Structure

We propose a self-consistent fixed-point equation on a dcpo (directed-complete partial order): U ≅ μF = F(μF, μF) = colimⁿ Fⁿ(⊥) ≅ μF. Four foundational unsolved problems — the arrow of time, quantum measurement, fine-tuning, and the cosmological constant — emerge as structural faces of this single equation.