Early-Universe and Strong-Field Consistency of χ-Mediated Gravity: BBN, CMB, BAO, Gravitational Waves, and Pulsars

This deposit contains the complete manuscript, figures, and validation results for Paper #5 of a five-paper series investigating a χ-mediated wave-gravity framework as an alternative description of gravitational dynamics. While earlier papers in the series address galactic rotation curves and merger-scale gravitational displacement, the present work tests whether the framework preserves all established early-universe, large-scale, and strong-field gravitational observables by converging to General Relativity in regimes where χ ≈ 1. Dedicated validation experiments examine Big Bang Nucleosynthesis, CMB polarization, baryon acoustic oscillations and the matter power spectrum, gravitational-wave propagation speed, and binary pulsar dynamics. The results show that during the early universe and in strong-field systems, χ remains near unity and the framework reduces exactly to General Relativity, reproducing standard cosmological and relativistic predictions. Deviations arise only in low-density regimes relevant to galaxies and cluster mergers. Together with the preceding papers in the series, these findings demonstrate that no gravitational observations currently require the invocation of collisionless dark matter within the tested domains. This repository is self-contained and includes the final manuscript and all numerical results supporting the conclusions. No additional simulations are required to reproduce the reported findings.