Resolving the Strengthened Hubble Tension: JWST's Local Measurements in a Finite 3-Torus Universe (Follow Up Note)

The Hubble tension - the disagreement between early-universe (CMB-derived) Hubble constant H₀ ≈ 67 km/s/Mpc and local distance-ladder values ≈ 73-74 km/s/Mpc - has grown stronger with recent James Webb Space Telescope (JWST) observations. JWST's precise calibrations of Cepheid variables, Tip of the Red Giant Branch (TRGB) stars, and Type Ia supernovae independently confirm the higher local expansion rate, pushing the discrepancy to even higher statistical significance.

This follow-up note builds on my earlier proposal (Powell_3Torus_HubbleTension_2026) that a finite 3-torus (T³) topology - motivated by Thomas Buchert and collaborators' CMB analyses - can resolve the original tension without new physics. The key mechanism remains: the torus wavelength cutoff suppresses large-scale modes, biasing global CMB fits low when assuming an infinite universe, while local probes (on sub-torus scales) measure the undamped rate. JWST's reinforcement of the high local H₀ fits perfectly into this picture, treating it as the accurate, unaffected measurement. The strengthened tension thus becomes further evidence for finite topology rather than a crisis for ΛCDM.