QVP: Quantum Vacuum Percolation — A Toy Model for Holographic Vacuum Transitions in Cosmology

The Vacuum Latent Heat (VLH) paradigm represents a fundamental shift in cosmology, proposing a transition from a "smooth" universe to a "granular" one where spacetime actively participates in cosmic evolution through phase coexistence and defect formation. This framework derives its observables from thermodynamic principles in a hidden-sector scalar field, effectively resolving major ΛCDM tensions without the need for undetected particles. As of January 7, 2026, the scientific community is leveraging data from Euclid, Gaia, and DESI to validate this model as the leading successor to the Standard Model of Cosmology. The Quantum Vacuum Percolation (QVP) model proposes a first-order vacuum phase transition driven by holographic entanglement entropy, yielding a granular spacetime that resolves \LambdaCDM tensions in a toy framework. Deriving from a scalar action with area-law entropy terms, QVP's equation of state w_{\text{QVP}}(z) forecasts phantom crossing at z \approx 0.5, addressing Hubble and S_8 tensions without particles. Mock forecasts, benchmarked to 2023--2024 data trends, predict > 0.85 local-global cross-correlations (e.g., Gaia-like rotation declines, DESI jerk peaks). Illustrative MCMC on simulated datasets yields \DeltaBIC \approx -6.2 favoring QVP over \LambdaCDM. Falsifiable via Euclid ghost lensing (\kappa < 20\% vs. NFW), LiteBIRD V-modes, and LISA GW skewness (0.1\text{--}0.3). This speculative program bridges quantum gravity and cosmology, with parameter exclusions for non-detections.