THE ZERO-CURVATURE OPERATOR OF LIGHT

This paper establishes the invariance of the speed of light as a rigorous operator‑geometric identity within Wasserstein geometry. It proves that the electromagnetic and gravitational propagation operators are W2‑isometries with identical canonical curvature K=0, demonstrating their geometric equivalence. The biconditional relation between constant light speed and zero curvature shows that these properties are mathematically identical. Extending this result, a unified operator family classifies all classical fields by curvature regime, providing a precise operator‑geometric foundation for unification.