Traversable Wormhole Geometry Reconstruction from the Rotation Curve of NGC 3198: A Comparative Study of Dark Matter Halo Profiles

Abstract

We develop an observation-driven framework that reverses the standard wormhole approach: instead of assuming a Morris--Thorne traversable wormhole geometry and deriving the supporting matter, we reconstruct the wormhole metric directly from the observed rotation curve of the spiral galaxy \mbox{NGC\,3198}. Using SPARC data ($D=13.8\,\mathrm{Mpc}$; 43 measurements over $0.32$--$44.08\,\mathrm{kpc}$), we fit four dark-matter halo profiles -- Hernquist, Navarro--Frenk--White (NFW), Burkert, and Einasto -- through $χ^2$ minimisation with the Nelder--Mead algorithm. For each best-fit density profile $ρ(r)$, the redshift function is reconstructed from the circular geodesic relation $f&#39;(r)=v^2(r)/r$, while the shape function follows from the Einstein field equations, $b&#39;(r)=8πGρ(r)r^2/c^2$. We define the dimensionless wormhole indicator $\mathcal{W}(r)=b(r)/r$ and evaluate it across the observed galactic domain. All four profiles satisfy $\mathcal{W}(r)\ll1$, implying that the observed region lies entirely within the traversable exterior of the reconstructed wormhole geometry. The flare-out condition $b&#39;(r)<1$ is satisfied everywhere by several orders of magnitude. The cored Burkert and Einasto profiles exhibit null energy condition (NEC) violation near the galactic centre, indicating effective exotic matter compatible with wormhole support, whereas the cuspy Hernquist and NFW profiles preserve the NEC. Among all models, the Burkert profile provides the best fit ($χ^2_{\rm dof}=2.545$), the largest wormhole indicator ($\mathcal{W}_{\max}=5.62\times10^{-7}$), and the strongest NEC violation, suggesting that the observationally favoured dark-matter distribution can also sustain a traversable wormhole. These results establish galactic rotation curves as a potential observational probe of wormhole physics.