Predicting Extra Gravity from Baryonic Structure in Galaxy Dynamics, Cluster Masses and Weak Lensing

Can the extra gravity attributed to dark matter be predicted directly from ordinary matter, rather than fitted with a separate dark halo for each system? This work investigates this possibility through an effective geometric-response framework, in which observed baryonic structure determines the additional gravitational field. Unlike conventional halo-fitting approaches, we calibrate its response relations on reference samples, freeze their parameters, and test their predictive power across independent systems and observables—from galaxy rotation curves to cluster dynamics and gravitational lensing. The results include predictions for 46 galaxy clusters with a mean absolute mass error of 19.8%, a 30.3% improvement in galactic residual-profile accuracy, and successful predictive transfers to cluster weak-lensing measurements without recalibrating on the lensing data. Together, these tests establish an empirical case for a geometric route to explaining gravitational phenomena commonly attributed to dark matter. The central question is no longer simply whether extra gravity can be fitted, but whether it can be predicted from the baryonic structure alone.