A Nonequilibrium Effective Field Theory of Coarse-Grained Spacetime Entropy Transport

We present a covariant nonequilibrium Effective Field Theory (EFT) for cosmological structure formation designated Relational Synchronization Cosmology (RSC). The framework models large-scale structure evolution as a weakly nonlocal, finite-band, dissipative transport medium governed by coarse-grained spacetime entropy flow and fading causal memory. The theory is formulated through a Schwinger–Keldysh closed-time-path (CTP) action principle and introduces a scalar recoverability field identified with the coarse-grained Shannon entropy density of the cosmic spacetime network. The construction proceeds through a sequence of formal closures: ontology, variational completion, gauge consistency, renormalization-group flow, perturbative hierarchy derivation, ultraviolet loop stability, numerical implementation architecture, parameter identifiability, nuisance-sector marginalization, and explicit empirical falsification criteria. The framework predicts a correlated finite-band observational signature spanning: scale-dependent growth suppression in , gravitational slip running , Weyl lensing modification , nontrivial void boundary displacement, and scale-dependent non-Gaussian bispectrum running. Unlike infinitely deformable modified-gravity parameterizations, the theory is constructed to collapse continuously back into standard CDM under null observational detection, making the framework highly constrained and explicitly falsifiable.