An Inverse-Square Law from a Future-Phase-Position Acceleration Map and Harmonic Closure in a Closed Two-Body AB Phase System

This preprint reanalyzes a previously published closed two-body AB phase-system experiment in which a nonzero acceleration-like second-difference structure emerged from the unlabeled relation f_AB without introducing an external force law, background spacetime, gravitational equation, or Coulomb equation. The earlier sweep varied the initial positional-phase deviation as an amplitude while keeping the harmonic update period fixed, and therefore produced a proportional native readout rather than an inverse-square dependence. The present work interprets a future phase position on the closed orbit as a relational rotation center and uses the acceleration map alpha=R omega^2. For every nonzero integer harmonic n, the same harmonic closure fixes both the phase-cell width Delta theta_n=2 pi/|n| and the angular speed omega_n=n omega_1, giving |omega_n| Delta theta_n=Omega. Their connection yields alpha_n=R Omega^2/(Delta theta_n)^2. Under the specific conditions of the reported experiment, the inverse-square law is established. No inverse factor, area-dilution term, spherical shell, external force, or gravitational constant is inserted. The existing numerical data also verify the nonzero acceleration-like second difference and exact closure residual for all eight tested conditions. Generalization to arbitrary closed systems, harmonic arrangements, nonharmonic updates, or distance readouts remains untested; the paper does not identify the result with standard gravity.