Origin of the Diffuse Gamma-Ray Anomaly from First Principles: Phase Friction and Elastic Slip in the Hydro-Elastic Model (HEM)

Current astrophysics records a statistically significant excess of diffuse gamma radiation in the Milky Way halo, peaking around 20 GeV. The Standard Model attempts to phenomenologically explain this phenomenon through collisions of hypothetical particles. This article applies the engineering principles of the continuum Hydro-Elastic Model (HEM) and shows that this excess is an analytically derivable acoustic manifestation of macroscopic phase friction. We deduce that the motion of rotating baryonic macro-knots along the 3D membrane induces a mechanism of elastic friction and slip in the upper Phase B. By applying the topological volume of the hypersphere boundary layer (2π²) to the fundamental inertia of the nucleon, we derive the base shear barrier Eₜₕᵣₑₛₕ ≈ 18.51 GeV. Subsequently, we analytically derive the phase strain hardening coefficient (Strain Hardening), by which the rotation dynamics of the galactic vortex (v ≈ 235 km/s) shifts the emission energy threshold to a value of ≈ 20.50 GeV. This mechanism exactly and causally reconstructs the empirically measured broad energy peak of the Fermi-LAT satellite.