The Cosmic Refrigerator: Gradient-Driven Diffusion of Zero-Point Energy Across the Cosmological Horizon as Dark Energy

The Cosmic Refrigerator: Gradient-Driven Diffusion of Zero-Point Energy Across the Cosmological Horizon as Dark EnergyThis paper proposes that the observed late-time acceleration of the universe arises from the slow outward diffusion of zero-point vacuum energy across the cosmological horizon, driven by a small super-horizon vacuum-energy gradient. The model is formulated phenomenologically using established concepts from quantum field theory in curved spacetime and thermodynamics. A central element of the framework is its set of distinctive observational predictions. These include a horizon-aligned dipole anisotropy in both the CMB and large-scale structure, directional variation in the Hubble expansion rate, and a redshift-dependent growth of anisotropy. The paper presents these predictions in detail, along with falsification criteria and a discussion of how they can be tested with upcoming surveys. This version introduces an expanded treatment of the model’s predictions and adds a new section outlining the technical steps required for a future linear perturbation analysis. The framework remains phenomenological. Its two central assumptions — the origin and amplitude of the super-horizon gradient, and the microphysical value of the effective diffusion coefficient — are stated explicitly as open theoretical questions. Numerical results were generated using the accompanying interactive Colab notebook. Future observations with Euclid, the Nancy Grace Roman Space Telescope, LiteBIRD, and DESI data releases will provide important tests of the model’s predictions.