The Hubble Tension Through the Lens of GCST Global Complexity–Stability Theory as a Framework for Resolving the Discrepancy in the Cosmic Expansion Rate

Abstract The Hubble Tension — a ~5–6σ discrepancy between local measurements of the Hubble constant H₀ ≈ 73–74 km/s/Mpc (Cepheids + Type Ia supernovae) and early-universe inferences H₀ ≈ 67–68 km/s/Mpc (Planck CMB + ΛCDM) — remains unresolved. Global Complexity–Stability Theory (GCST) interprets the tension as a late-time structural debt effect in cosmic expansion. The stability index declines in the late universe as complexity C grows faster than global dissipation γ. Accumulated debt D forces accelerated expansion locally, producing higher effective H₀ compared to early-time (CMB) values. This paper formalizes the link between structural debt D and the energy-momentum tensor T_ in Einstein’s equations, showing that D acts as an effective additional source term contributing to the observed late-time acceleration.