Bimodal Regime Structure in Galactic Rotation Curves: Evidence for Distinct Dynamical States and a Field-Based Interpretation of the Dark Matter Effect

This work analyses 164 galactic rotation curves from the SPARC database and develops a field-based interpretation of the dark matter effect within the framework of the Universal Quantum Foam Hypothesis (UQSH). The empirical excess term C(r) = v^2_obs(r) − v^2_bar(r) reveals, after normalisation, a consistent structure of preferred dynamical regimes. Global fits identify two dominant states: a peak regime with scale parameter q ≈ 0.5–1.0, encompassing mainly low-surface-brightness galaxies and dwarf galaxies, and a diffuse regime with q ≈ 3.0, dominated by more massive spiral galaxies. Individual fits yield a distribution of roughly 62% peak systems, 26% diffuse systems, and 12% in the transition zone. An analysis of the dynamic factor D = g_obs/g_bar as a function of the maximum rotation curve radius reveals a statistically significant negative correlation (r = −0.31, p = 0.0001). Beyond approximately 50–80 kpc, D converges systematically toward 1. This empirical instability boundary marks the spatial range within which coherent field organisation produces measurable amplification. In the UQSH framework, light is interpreted as a spherically propagating tension front that follows the accumulated field geometry. In this picture, the convergence κ does not measure the instantaneous mass density, but the projected field curvature. An updated UQSH model of the Bullet Cluster reproduces the observed offsets between gas centres and κ-peaks of 219 kpc and 228 kpc without requiring an additional non-baryonic matter component. Within this framework, the dark matter effect is not attributed to missing particles, but arises as an intrinsic property of the field medium. Baryonic structures act as stable field configurations that spatially pre-stress the medium. Through continuous radiation, they excite the field and generate overlapping deformations. While individual contributions partially relax, their continuous renewal leads to a dynamically maintained, time-averaged field configuration that appears as a large-scale effective deformation. The nonlinear superposition of these contributions — bound baryonic mass, continuous excitation, and the resulting field organisation — produces a large-scale field tension that appears observationally as the dark matter effect. On galactic scales, the empirical instability boundary at approximately 50–80 kpc sets a natural spatial limit for coherent field organisation. In galaxy clusters, the contributions of many saturated structures superpose into a collective field tension that systematically enhances the lensing signal beyond the baryonic expectation. The universal fits show high internal consistency within each regime, with mean squared errors of MSE ≈ 0.016 in the peak regime and MSE ≈ 0.06–0.13 in the diffuse regime. This universality contrasts with expectations from continuous halo models and supports the interpretation of preferred dynamical states arising from field organisation.