ATMAN v5.0 Paper XII: The Invariable Plane of the Three-Perturber Solar System — An Independent Observational Test with ATMAN v5.0

Paper XII of the ATMAN v5.0 series. The inclination of the total angular momentum vector (invariable plane) of the Solar System is computed with and without the three hypothetical trans-Neptunian perturbers, using ATMAN v5.0 over 10 Myr. The control run (four giant planets only) yields iinv=1.617°±3×10⁻⁸°, in excellent agreement with the observed value of 1.574° (Souami & Souchay 2012), confirming ATMAN v5.0 angular momentum accuracy. The three-perturber run yields 9.995°±5×10⁻⁸°, a displacement of +8.421° from the observed invariable plane, driven by the combined angular momentum of Solution B (i=10°), Erebo (i=30°), and P3 (i=20°). This displacement constitutes a novel independent observational prediction of the three-perturber model, motivating the inclination sweep of Paper XIII. SHA-256: 6a65ebb0d884355962d1ac75ce982ed999c923b15529b3ee90a4b0d826a8c0d1. Paper XII of the ATMAN v5.0 series. Keywords: Kuiper belt, trans-Neptunian objects, N-body simulations, ATMAN v5.0, invariable plane, angular momentum, three-perturber system, outer solar system, observational prediction