Galactic rotation curves remain flat at radii where Newtonian gravity predictsKeplerian decline. Dark matter halos and MOND have been proposed to resolvethis tension. I introduce Vortex Dynamics, a framework in which spacetime aroundgalaxies possesses a Gabriel’s Horn / Torricelli’s Trumpet-like geometry induced byframe-dragging from the central black hole. This geometry adds a logarithmic termto the gravitational potential: Φ(r) = −GMb/r − v2flat ln(r/Rg). From this singlemodification, Vortex Dynamics derives: 1) flat rotation curves, 2) the BaryonicTully-Fisher Relation v4flat ∝ Mb, and 3) the MOND acceleration scale a0 = G/V ∗2with V ∗ = 0.338 kpc M−1/2⊙ as a universal constant. Comparison with Milky Wayand SPARC galaxy rotation curves shows Vortex reduces χ2 by 5× vs Newton andmatches data to < 3% using only baryonic mass. No free parameters per galaxyare required. Dark matter becomes unnecessary at galactic scales.
Sakhile Nyembe (Tue,) studied this question.