A Structural Time-Frequency Interpretation of Running Vacuum Cosmology

This work proposes a late-time cosmological framework in which vacuum energy density acquires a structural contribution proportional to the square of the Hubble parameter: ρ_Λ(H) = ρ₀ + νH² The model introduces a time-frequency interpretation of vacuum dynamics while preserving standard matter and radiation evolution. Deviations from ΛCDM remain perturbative for small coupling parameter ν. This work focuses exclusively on late-time cosmology and does not modify early-universe inflation. Observational testing using H(z), BAO, supernova, and CMB datasets is required for parameter estimation. Collaboration for cosmological data fitting and phenomenological analysis is welcome.