The Radial Acceleration Relation (RAR) — the tight empirical correlation between observed centripetal acceleration gobs and baryonic Newtonian acceleration gbar across 153 galaxies in the SPARC sample — is shown to be the direct observational signature of the two-scale T2/T2* brane-current boundary established in Paper CXXXVI. The transition between the Newtonian (Scale-1, inner) and MOND (Scale-2, outer) regimes occurs at exactly rT2∗= p GMbar/a0, where gbar/a0 = 1 by construction. At this boundary, the simple MOND interpolating function evaluates to: ν(1) = 1 2 + r 1 4 + 1 = 1 + √ 5 2 = φ, the golden ratio, which we show is a geometric consequence of the G2 automorphism structure of the brane. We further demonstrate that the rotation curve diversity prob- lem — the large scatter in inner rotation curve shapes at fixed asymptotic velocity — is quantitatively explained by the ratio rbar T2∗/rDM T2∗= p Mbar/MDM: galaxies with high baryonic-to-dark-matter mass ratios have larger baryonic sumps and steeper inner pro- files, while ultra-diffuse galaxies (UDGs) have rbar T2∗/rDM T2∗∼0.03–0.22, explaining their Part of the One-Octonion Brane-Bulk Framework series. Anchor DOI: 10.5281/zenodo.19120873. Community: one-octonion-brane-bulk. Author: Bharathi Dasan Jagadeesan, M.D., University of Minnesota. ORCID: 0000-0002-1143-941X.
Bharathi Jagadeesan (Sat,) studied this question.