Dissolution and Expansion as a Single Process: A Structural Derivation of the Cosmological Acceleration Scale

The Milgrom scale, a₀ ≈ 1.2 × 10⁻¹⁰ m/s², is the empirical acceleration threshold below which galaxy rotation curves depart from Newtonian predictions. Its numerical proximity to c × H₀/(2π) has been noted since 1983 but has never been derived from first principles. This paper derives it from a structural framework developed in prior work (Shchevyev 2026a; 2026b). The central argument is that K-accumulation — the structural process of dissolution — is not merely analogous to cosmic expansion but is the same process operating at different scales. This entails that the cosmic K-accumulation rate (H₀) must set the local K-dominance threshold (a₀), with the proportionality constant c forced by dimensional necessity and the factor 1/(2π) derived from the closed cycle of co-necessary structural operators. The derivation yields a testable prediction concerning the Hubble tension: a₀ should encode the local Hubble rate, not the CMB-inferred value, a consequence that distinguishes SPA from standard MOND and is verifiable by forthcoming Vera Rubin Observatory data.