Researchers have developed a new theoretical formulation to describe the behavior of conductors and superconductors in stationary spacetimes, without the limitations of weak fields or low velocities present in previous studies. This work addresses the electrodynamics of superconductors following London's phenomenological approach, extending it to include the effects of gravity in a more general way. The novelty lies in the inclusion of additional terms derived from gravitationally-induced constitutive equations, which were not considered in the weak-field and low-velocity limit.

The study begins by defining the 3-force acting on charged particles in gravitational and electromagnetic fields, and derives its explicit form using a general spacetime decomposition formalism. To highlight the observer's influence, the force equation is applied to free charges in superconductors within stationary spacetimes, employing both 'threading' and 'slicing' decomposition formalisms. This approach allows for a more complete description of how gravity affects electromagnetic phenomena in these materials.

By applying the stationary condition in the superconducting state, the authors have obtained generalized versions of the Schiff-Barnhill and Meissner effects. These effects, fundamental in superconductivity, now incorporate the additional terms arising from the interaction with strong gravitational fields. The consistency of the approach is verified by deriving the generalized Meissner effect also from the second London equation in stationary spacetimes, which reinforces the validity of the new formulation. This advance is crucial for understanding the physics of materials in extreme astrophysical environments or for the development of unified theories of gravity and electromagnetism.