Physics from SU(2) Phase Geometry on the 3-Sphere: Cosmology

Building on the SU(2) phase geometry framework introduced in "Physics from SU(2) Phase Geometry on the 3-Sphere: Foundation", I develop a cosmological model in which the universe is described as a compact 3-sphere S3 endowed with a global SU(2) phase field. In this approach, cosmological expansion, redshift, structure formation, and the dark sector emerge from the dynamics of nonlinear phase excitations. Black holes appear as topological concentrations of phase curvature that evaporate via SU(2) vortex emission. Dark matter is modeled as stable residual vortices, while dark energy arises from long-wavelength phase fluctuations. The model resolves the horizon problem without inflation, naturally suppresses vacuum energy, and supports a cyclic, non-singular evolution through phase reorganization. Observational consequences include testable correlations between black hole populations, dark matter distribution, and CMB anomalies. This work extends SU(2) phase cosmology as a coherent alternative to conventional models, rooted in compact geometry and topological field dynamics.