RCD Paper XII: Active Coherence Protection — Isomorphisms Between the RCD C-Field and Established Quantum Protection Mechanisms

We establish formal mathematical isomorphisms between the coherence field C proposed in Radial Coherential Dynamics (RCD) and four established quantum protection mechanisms: continuous quantum Zeno effect, topological energy gaps, continuous dynamical decoupling (CDD), and thermodynamic frustration of decoherence. Our results demonstrate that unprotected quantum entanglement collapses faster than classical schemes under realistic noise, and that only architectures incorporating a dynamic rigidity mechanism — isomorphic to continuous Zeno, topological gaps, or decoherence frustration — can surpass the classical binding limit. Recent experimental validations, including Google Quantum AI's surface code achieving error suppression factor Λ = 2.14 and JILA's Zeno suppression in ultracold KRb molecules, provide empirical grounding for these theoretical correspondences. We demonstrate that the mathematical role played by the RCD C-field is isomorphic to that realized by several established coherence-protection mechanisms, suggesting a common functional role across diverse physical implementations. This is Paper XII in the RCD series, continuing the Quantum Binding track initiated in Paper XI. Keywords: coherence protection, quantum Zeno effect, topological protection, decoherence-free subspaces, quantum error correction, RCD theory, binding problem, isomorphism, Radial Coherential Dynamics