Resolution of Hubble Cosmic Age Tension in Thermodynamic Relativistic Gravity - Classical General Relativity (TRG-CGR) Framework

The determination of the cosmic age in standard ΛCDM cosmology is tightly coupled to thepresent-day Hubble constant, leading to a persistent tension between early-universe measurementsinferred from the cosmic microwave background and late-time local determinations of the expansionrate. In this work, we introduce a split-epoch evaluation of cosmic time within the ThermodynamicRelativistic Gravity–Classical General Relativity (TRG-CGR) framework, in which the cosmic ageis expressed as the sum of distinct early- and late-universe contributions governed by differenteffective expansion rates.We show that the dominant contribution to the cosmic age arises from the early universe, wherethe expansion rate is lower and the Hubble radius is large, while the late universe–despite exhibitinga higher locally measured Hubble constant–contributes only a small additional proper time. Usingstandard cosmological density fractions for comparison and assuming a spatially flat backgroundgeometry, we perform a step-by-step numerical evaluation of the cosmic age with a transitionredshift zt ≃ 0.01. The resulting total age remains consistent with cosmic microwave backgroundconstraints while simultaneously accommodating higher local measurements of H0.This split-epoch approach demonstrates that the Hubble tension and the associated age tensionare not fundamentally observational conflicts but arise from the assumption of a single globalexpansion history. The TRG-CGR framework naturally decouples late-time expansion from theaccumulated cosmic age, providing a physically consistent resolution without invoking additionaldark sector components or modifications to early-universe physics.