Vacuum Energy is Not a Constant: A Principle-Locked Route to Cosmic Acceleration

This paper develops a fully covariant 4-form framework in which vacuum energy is not a fixed constant but a dynamical quantity linked to the cosmic expansion. Unlike phenomenological approaches that leave the normalization of the vacuum term arbitrary, the model derives it from a principle-locked coupling, eliminating free parameters. The resulting vacuum sector is Lorentz invariant, ghost-free, and introduces no new propagating degrees of freedom. At the background level, the model reproduces standard ΛCDM expansion, while allowing small, monotonic deviations that translate into percent-level shifts in structure growth, the integrated Sachs–Wolfe effect, and redshift drift. These deviations are small enough to be consistent with present data but sufficiently directed to be testable with upcoming surveys such as DESI, Euclid, and SKA. This article is part of the Horizon Information Framework program, which develops a unified informational ontology for cosmology and quantum theory. The approach provides a mathematically rigorous and physically transparent route to cosmic acceleration, linking spacetime dynamics with informational and thermodynamic interpretations. It offers a falsifiable framework in which vacuum energy emerges as a dynamical but conserved effect of spacetime structure, rather than as a fundamental constant of nature. Relevant empirical background includes the Planck 2018 cosmological parameters and the LiteBIRD mission overview, which provide key observational benchmarks for testing the model.