Confrontation of the 7 - φ Dark Matter Ratio with DESI DR2 BAO and the Matter Power Spectrum A data note accompanying the prediction paper

The golden ratio prediction Ωcdm/Ωb = 7 - φ = 5.382 (Hess 2026) is confronted with DESI DR2 BAO measurements (Elbers et al. 2025) and the linear matter power spectrum computed with the CLASS Boltzmann code. The BAO distance ratios at the DESI Lyman-alpha effective redshift z = 2.33 are verified: DH/rd = 8.664 and DM/rd = 39.04 for the golden ratio model with Neff = 3.23 and H0 = 69.0, consistent with DESI at +0.3 sigma and +0.1 sigma respectively. The DESI neutrino mass constraint (Σmν 0.1 h/Mpc relative to Lambda-CDM, with phase-shifted BAO wiggles in the residuals, testable by Euclid and DESI 5-year. DISCLAIMER Generative AI was used to assist with literature screening / coding support / draft language revision. All AI-assisted outputs were independently checked by the author, and the author takes full responsibility for the final analysis and text. This is encompassing all the work that has been done and will be done. All code is under MIT licensing. All research papers are under Creative Commons License. All code, outputs and notes are included in the reproducibility bundle zip file.