Paper CLXXV: One-Octonion Bounce Dark Matter as Sump Relics: G2-Symmetric Realisation of the Gazta˜naga BHU Bounce

Gazta˜naga (arXiv:2602.17702, 2026) proposes that the Big Bang is a black hole bounce (BHU) and predicts two channels for relic dark matter: BDM-1 (horizon-reentry: pre-bounce BHs collapse to compact relics on re-entry) and BDM-2 (horizon-shielded: compact objects encapsulated by event horizons survive the bounce). We show that the One-Octonion Brane-Bulk Framework is the G2-symmetric physical realisation of the BHU scenario. Both share the same scale factor a(τ)/aB = cosh(τ/RB) (Gazta˜naga Eq. 22 = brane expansion from H+/H−annihilation in AdS5). G2 = Aut(O) is uniquely the bounce-survivor symmetry: it maps H+ ↔H−and is invariant under time-reversal. BDM Channel 1 is identified with the sump nucleation mechanism: Msump = a0r2/G, relaxation timescale Tsump = 72.65 Gyr, zero free parameters. BDM Channel 2 is identified with the H+/H−quaternionic black holes themselves, whose annihilation nucleates the brane. The bounce dark matter mass spectrum is quantised by the G2 root system. A new irrational LIGO signature is predicted: the BDM binary merger chirp ratio q = (2+ √ 3)2 = 13.928 . . . is transcendental and unique to bounce dark matter relics. Two formal predictions; zero free parameters. 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.