Paper CXIV: The 3:2 QPO Ratio from G2 5D/4D Dimensional Counting and the Universal ISCO Theorem Center for Magnetic Resonance Research

In the One-Octonion Brane-Bulk Framework, the universal 3 : 2 high-frequency quasi-periodic oscillation (HFQPO) ratio observed in accreting black holes, neutron stars, and white dwarfs is a topological consequence of brane-bulk dimensional counting at the innermost stable circular orbit (ISCO). The framework's brane is a 4D auxetic Fano truss embedded in a 5D AdS bulk; at the ISCO, the brane curvature reaches κeff = −1 universally (the Universal ISCO Theorem), forcing the effective dimensional count to be D = 5 (bulk) and d = 4 (brane). The ratio of vector- mode and spinor-mode counts in this regime is exactly 3 : 2 from G2 representation-theoretic dimensions of the orbit stabilizer. Confirmation in five published QPO observations: GRS 1915+105 (41 : 27 Hz, ratio 1.52, deviation 1.3%), XTE J1550-564 (184 : 276 Hz, ratio 1.50, exact), GRO J1655-40 (300 : 450 Hz, 1.50, exact), H1743-322 (165 : 240 Hz, 1.45, 3.3%), and 4U 1636-53 (580 : 870 Hz, 1.50, exact). Mean deviation 0.9% across the sample. Three falsifiable predictions registered, including a new 3 : 2 ratio prediction for the sun's solar oscillation spectrum at the radiative-convective interface. 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.