Spin-Tension Cosmology: A Unified Framework With Fine Structure, Chemical Periodicity, and Empirical Confrontation

This deposit contains the definitive version of the Spin-Tension Cosmology (STM) framework, a unified, strictly 3D field theory of cosmology and microphysics. STM derives all cosmic and atomic structure from a single spin-induced tension field $\psi$ on a 3-torus, without invoking dark matter, dark energy, inflation, or external fields. This manuscript introduces explicit mechanisms for fine structure and chemical periodicity, and provides quantitative, parameter-constrained fits to cosmological (CMB, BAO, SN) and nuclear/atomic data. All results are derived from first principles, with no ad-hoc functions, and the model is axiomatically closed and empirically falsifiable. The document includes full derivations, empirical fit statistics, and parameter tables, making STM a testable alternative to $\Lambda$CDM and a candidate for unified physics.