Gravitational Manipulation Theory v1.9: Model-Dependence of Native Screening and Cross-Experiment Constraint Robustness

Abstract

Gravitational Manipulation Theory (GMT) v1.9 tests whether the cross-experiment constraint structure established in GMT v1.7–v1.8 depends on the choice of screening model. GMT v1.7 made the screened-scalar constraint pipeline computationally reproducible, and GMT v1.8 reconstructed the single-body screening factor from first principles. Both versions, however, retained one structural assumption: the pipeline was built on the minimal (Z_2) symmetron with a (\phi^4) self-interaction. GMT v1.9 relaxes that assumption through a controlled model-dependence study. A model-agnostic single-body screening factor, [\kappa_s^{(M)} = Q_{\mathrm{eff}}^{(M)} / Q_{\mathrm{bare}}^{(M)},] is defined using the same solver, normalization, and charge-extraction procedure across models. The minimal symmetron ((k=2)) is used as the baseline and compared with four tested alternatives: a generalized symmetron ((\phi^6,\ k=3)) and inverse-power chameleon thin-shell models with (n=1,2,4). Only the screening potential/mechanism is changed; the master grid, Eöt–Wash and HUST observational bands, calibration, observational mapping, and exclusion criterion remain fixed at their GMT v1.8 values. The individual experimental exclusions are model-sensitive: Eöt–Wash: (155 \rightarrow 175, 158, 158, 157) HUST: (1007 \rightarrow 1028, 1091, 1088, 1085) Nevertheless, the cross-experiment Eöt–Wash ∩ HUST constraint core is retained under every tested alternative: 38 \rightarrow 40, 43, 43, 42,] with (J_{\mathrm{overlap}}\ge 0.884) and zero baseline cells lost in every case. Thus, the minimal-symmetron constraint core is contained in every tested alternative constraint set. Deep-screening asymptotics are evaluated using the same Aitken (\tau)-saturation procedure adopted in GMT v1.8. Numerical-governance checks also identify and correct two deep-band artifacts through physics-consistency tests rather than tuning to a target. The demonstrated robustness is staged across an order deformation, a different screening mechanism, and the chameleon (n)-family. All comparisons are screening-surface swaps at the fixed GMT v1.8 mapping. This release therefore does not claim universal robustness across the screened-scalar class or constitute a chameleon-native ((\beta,\Lambda,n)) constraint reconstruction. No experimentally demonstrated gravitational manipulation or engineering controllability is claimed. The archive includes the compiled manuscript, nine figures, LaTeX paper source, model definitions, numerical outputs, frozen GMT v1.8 inputs, solver and propagation scripts, machine-readable model-dependence matrices, and reproduction scripts.