Emergent MOND from eta(L): Deser-Levin modular length, the sqrt(2) factor, and a parameter-free mu function

EN: A parameter-free MOND law and acceleration scale are derived from eta(L) and shown to reproduce the SPARC radial-acceleration relation. This manuscript is part of a series of 17 papers (A–S). For a compact self-contained guide to the full program, including epistemic levels, falsification roadmap, and all DOIs, see the program summary: https://doi.org/10.5281/zenodo.19218767 Abstract We derive mu(x) = x/(1 + x) from the ansatz eta_eff(L) = eta_bar + (xi/4pi) L / l_*^3 and G_eff = 1/(4 eta_eff), interpreting G_eff(L) as a long-distance effective coupling, not as a variation of the local laboratory G_N. In the static de Sitter patch, the Deser-Levin temperature fixes a modular length L_eff = c^2 / sqrt(a^2 +…