Logarithmic-Spiral Tubular Wormholes in Einstein–Cartan–Maxwell Theory: The End of the Exotic Matter Paradigm and the Torsional Shield Theorem

This work presents a complete analytical construction of a traversable wormhole in the Einstein–Cartan–Maxwell framework that requires no exotic matter. By embedding a tubular neighborhood of a three-dimensional logarithmic spiral into a non-Riemannian spacetime, we derive a metric whose throat is sustained entirely by geometric invariants: curvature, torsion, and radial profile. We prove the Rossetti–Geometric Autonomy Theorem, demonstrating that the existence condition for the throat is independent of the axial magnetic potential As(0). The Null Energy Condition is effectively violated by torsional contributions, eliminating the need for unphysical stress-energy sources. Finally, we derive the Radial Master Equation and show that the effective potential exhibits a positive-definite divergence at the throat, establishing the Torsional Shield Theorem: a natural, infinite repulsive barrier that guarantees dynamic stability. This work marks the end of the exotic matter paradigm and introduces Torsiodynamics as a new geometric foundation for traversable wormholes.