Dark Halos as Geometric Residuals of the Baryonic Transition

Abstract

This work tests whether the outer structure usually attributed to galactic dark halos can be described as a geometric residual of the baryonic circular field. Starting from published rotation-curve mass models, the analysis defines q = g_obs − g_bar and m = q/R, anchors each galaxy at the baryonic transition q ≃ g_bar, and measures the exterior residual slope γ as a proxy for halo width. Across SPARC, the residual width is strongly ordered by baryonic transition and central-depth quantities, reconstructs held-out outer rotation curves, survives robustness and negative-control tests, and reappears in external mass-model samples. The accompanying reproducibility package includes the scripts, bundled inputs, derived tables, and figures needed to rerun the reported tests or apply them to independent catalogs. This record contains the manuscript and reproducibility package for Dark Halos as Geometric Residuals of the Baryonic Transition: Empirical Tests with SPARC and External Mass Models.