CMB Acoustic Peaks as Self-Interference of Auxetically Retained Fano Quantum Fluc- tuations: Why Neighboring Brane Reections Are Not Required for the Primary Peak Structure

Paper XXIII identied the CMB acoustic peaks in part as bulk gravita- tional wave echoes from neighboring branes, arriving at the last scattering surface as periodic compressions. Papers LXXILXXIII now provide a more parsimonious and self-contained explanation: the acoustic peaks are shape-memory interference patterns of the initial Fano quantum uctuations, retained by the auxetic brane fabric with- out requiring any external source. The mechanism has three steps. First, the initial Fano node superpositions at nucleation (Paper LXXIII) create a specic interference pattern of density uctuations across the nascent brane. The logarithmic delocalization ξλ(E) = (ℓP /λ) ln(mPl/E) (Paper LXII) is scale-invariant it gives the same frac- tional uctuation amplitude at all scales producing the Harrison-Zel'dovich spectrum (ns ≈1) without ination. Second, the ν = −1 auxetic brane fabric retains these initial uctuations as shape memory (Paper LXXI): as each mode enters the acoustic horizon at scale rs, it oscillates as a standing wave, and the auxetic property locks the oscillation amplitude against Silk damping. Third, the self-interference of each mode with its own shape-memory-retained state creates the periodic comb of acoustic peaks at ℓ= nℓ1 not as reections from another brane but as the standing-wave resonances of the brane fabric's own retained memory. The neighboring brane mechanism of Paper XXIII is retained for the specic large-scale anomalies (Axis of Evil, Cold Spot, H0 and S8 ten- sions) which require external bulk interactions. But the general acoustic peak structure at ℓ≥100 is fully explained by the internal shape-memory mechanism, giving a simpler, more testable, and more parsimonious derivation of the most prominent feature of the CMB. The Harrison-Zel'dovich primordial spectrum is derived (not assumed) from the logarithmic Fano delocalization, with ns = 1 −2/ ln(mPl/H0) = 0.9667 within 0.5% of the Planck-measured ns = 0.9649±0.0042. Three new predictions follow (Predictions 161163). 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.