Recent theoretical developments in Open System Cosmology provide a self-consistent geometric explanation for major anomalies in modern physics (Hubble Tension, Dark Sector, Baryogenesis) by embedding the Universe in a thermodynamic Bulk. To transition from theoretical architecture to experimental verification, we present a comprehensive multi-messenger observational strategy. We consolidate the predictions of this framework into a Master Falsifiability Matrix, correlating signatures across disparate regimes: High-Energy Particle Physics (IceCube), Galactic Dynamics (Euclid), Black Hole Thermodynamics (EHT/LIGO), and Cosmic Birefringence (LiteBIRD). We define the specific regimes of energy and curvature where the bulk interaction becomes dominant over Standard Model backgrounds. Specifically, we predict a triple-coincidence signature: (1) A flavor deficit in PeV electron-neutrinos due to bulk leakage; (2) A constant surface density in galaxy clusters driven by bulk tension; and (3) A non-zero polarization rotation in the CMB. Crucially, we propose the "Geometric Correlation Test" (The Golden Spike): these effects must be geometrically aligned with the large-scale dipole anisotropy (Dark Flow). This protocol serves as the definitive handbook for testing the hypothesis of the Universe as an open thermodynamic system.
Giovanni Frisina (2026) studied this question.