Numerical Tests of Galaxy Rotation Curves in Stiffness Field Cosmology

Building on the stiffness saturation mechanism developed in [16, 17], this companion study presents numerical tests of Stiffness Field Cosmology (SFC) against representative galaxy rotation curve data. We solve the nonlinear flux-limited stiffness field equation under radial symmetry, with baryonic mass distributions fixed by observations. No galaxy-dependent parameters are introduced: the universal acceleration scale a is fixed globally from vacuum transport prop- erties and is not fitted to galactic data. Uncertainties in baryonic distributions are propagated via Monte Carlo sampling, while vacuum parameters remain unchanged. The resulting acceleration profiles reproduce the observed shapes of rotation curves across low-surface-brightness, high-surface-brightness, and dwarf galaxies, and recover the baryonic Tully–Fisher relation within observational scatter. These results demonstrate that stiffness saturation provides a quantitatively viable ex- planation of galactic rotation curves in the weak-field regime, without dark matter, phe- nomenological interpolation functions, or hidden tuning.