A Unified Substrate Origin of MOND Dynamics and CMB Thermalization

A periodic scalar substrate with a cosmological background gradient produces two large scale phenomena that are usually treated as unrelated. In the infrared, long wavelength gravitational modes propagate through the substrate and acquire a gradient dependent kinetic renormalization. This reproduces the MOND interpolating function and gives the acceleration scale a0 = cH0. In the ultraviolet, photon modes couple to the same substrate through a derivative fermion interaction. The resulting super Ohmic spectral density J(ω) ∝ ω5 and the fluctuation dissipation relation give kBTCMB = Cm2ϵ2 Both results follow from the same mechanism. Long wavelength fields move through a rapidly oscillating periodic medium whose response depends on the local gradient. The framework links galactic dynamics, the CMB temperature, and a heavy substrate scale near 1016 GeV in a single structure.