Finite-domain inverse reconstruction of a Morris--Thorne-type wormhole candidate with a derivative-consistent $f(R)$ curvature sector

Abstract

We present a finite-domain inverse reconstruction of a Morris--Thorne-type wormhole candidate as a methodological benchmark for constrained numerical model building in modified gravity. The throat condition and local flare-out behaviour are embedded analytically in the shape-function parameterization, while the redshift profile is kept finite by construction. Rather than fitting $f(R)$, $f_R(R)$, and $f_{RR}(R)$ as independent numerical arrays, a positive analytic generator is assigned to $f_{RR}(R)$ and integrated to obtain a derivative-consistent reconstructed curvature sector. The frozen reconstruction is evaluated on 10,019 radial nodes over $r\in [1,10^5]$. The corresponding Ricci-scalar trajectory spans $-1.1317\times 10^{-9}\le R\le 1.999999998$ and is weakly non-monotonic, so no inversion $r=r(R)$ is required. On the same finite grid, the reconstructed source variables retain positive pointwise energy-condition margins, the coordinate-radial null-energy integrals are positive both globally and in the near-throat band, and the maximum normalized tidal-curvature ratio is $0.8666<1$. The reconstructed source-side closure diagnostic has a maximum absolute residual of $5.3246\times 10^{-5}$. The source closure is phenomenological rather than derived from a unique microphysical matter Lagrangian or a uniquely specified curvature--matter coupling function. Accordingly, the result is not presented as a full field-equation solution of a specified nonminimally coupled $f(R)$ theory, a stability proof, an exterior-matched global spacetime, or an observer-dependent safe-traversal model. It instead provides a finite-domain computational benchmark for auditable inverse reconstruction of Morris--Thorne-type geometries in modified gravity.

23 pages, 6 figures, 2 tables; supplementary material included as ancillary PDF