Metageometric Oscillations in Galactic Halos and the 20 GeV Fermi Excess

This work applies the Metageometric Framework (Theory of Cymalogy) to the ∼20 GeV gamma-ray excess reported in the Milky Way halo from 15 years of Fermi-LAT data. In this framework, spacetime emerges from an external causal structure (Z_0), and galactic halos act as resonant cavities supporting discrete oscillation modes driven by khron dynamics. The fundamental mode produces a narrow spectral feature consistent with the observed peak, offering a structural alternative to dark matter annihilation. Crucially, the mode energy scales with the halo's potential depth (E_1∝\sqrt{M}): the corresponding signal in dwarf spheroidal galaxies is shifted below the Fermi-LAT window rather than merely suppressed — naturally resolving the tension that annihilation models face with dwarf-galaxy null detections. The same causal mechanism previously accounted for the early emergence of massive galaxies at z ≈ 16, now confirmed by JWST. The model predicts a comparable excess in other massive halos, notably M31, scaling with rotational velocity — a directly testable signature. _______ Keywords: astrophysics • cosmology • gamma rays • Fermi LAT • Milky Way halo • dark matter alternative • galactic halos • NFW profile • cosmic structure formation • emergent spacetime • theoretical physics • unified physics • cymalogy • Open Science •