Monotonic drift signatures in galaxy rotation-curve residuals and their link to dynamical non-equilibrium

I investigate whether galaxy rotation curves exhibit signatures of non-adiabatic dynamical response beyond purely instantaneous equilibrium descriptions. Using two independent rotation-curve compilations (SPARC and PROBES), I introduce a parameter-light diagnostic that quantifies coherent outer-disk drift in residuals relative to a smooth baseline. I find that the drift amplitude increases monotonically with independent indicators of dynamical non-equilibrium, such as data-quality flags and kinematic asymmetries, while remaining consistent with zero in ultra-quiet control subsets selected by strict geometric and observational criteria. This behavior is replicated across both catalogs and persists under conservative quality cuts and explicit null tests. These results demonstrate that rotation-curve residuals encode systematic, environmentdependent structure inconsistent with purely static equilibrium descriptions. While I do not assume a specific physical mechanism, the observed trends are consistent with a delayed or non-adiabatic response of galactic dynamics to evolving mass distributions. The analysis provides a falsifiable, model-independent observational result and motivates further work aimed at identifying the underlying physical origin and associated timescales.