Resolving the Hubble Tension Through Hypersphere Cosmology: A 4D Geometric Framework

This paper proposes a finite, closed-universe geometry in which the observable Universe is modeled as the three-dimensional surface of a four-dimensional hypersphere. This framework offers a geometric interpretation of the Hubble tension by showing that light from distant sources traverses the curved, expanding 3-sphere surface, resulting in projection effects when analyzed under flat-sky assumptions. By reframing the discrepancy in H₀ measurements as a geometric rather than purely dynamical phenomenon, this model maintains compatibility with general relativity on local scales while eliminating the need for exotic physics or statistical anomalies. The paper also addresses implications for BAO angular scales, CMB curvature, and observational tests that could validate or falsify this framework.