Dark Energy as Cosmic Temporal Tension

This paper presents a dedicated, comprehensive formulation of dark energy within the Granular Cosmic Vacuum (GCV) framework. In contrast to the standard view that associates dark energy with a cosmological constant, a scalar field, or quantum vacuum energy, the GCV model interprets dark energy as the temporal tension of a closed cosmic string that constitutes the structure of cosmic time in the intergalactic domain. The fundamental tension scale is set by Planck physics and is geometrically damped across many hierarchical levels, from the Planck length to the Hubble radius, yielding the observed dark- energy density ρΛ≈10−9J/m3ρΛ≈10−9J/m3 without fine- tuning or quantum vacuum contributions. We develop the ontology of the temporal string, define its structural damping through an exponential map, derive the effective energy density and equation of state, and clarify why the traditional cosmological constant problem arises from a category mistake between distinct physical domains. We also outline observational consequences, in particular an additional, small damping effect on high- energy gamma rays that propagate through the granular vacuum, providing a falsifiable prediction of the temporal- tension model of dark energy.