Structure-Dependent Cosmological Expansion as a Possible Resolution of the Hubble Tension

The discrepancy between early- and late-time measurements of the Hubble constant remains one of the central unresolved problems in cosmology. In this work, we propose a phenomenological extension of the standard expansion model in which the Hubble parameter depends not only on the global energy density but also on the amplitude of large-scale structure. We introduce a structure-dependent correction term proportional to the variance of density fluctuations. Using a simplified numerical analysis, we demonstrate that this model can reduce the Hubble tension while preserving standard cosmological behavior at high redshift. The model predicts a measurable correlation between local density environments and the inferred Hubble parameter.