Perturbative approach for the dynamics of the quantum Zeno subspaces

We investigate the dynamics of the quantum Zeno subspaces which are the eigenspaces of the interaction Hamiltonian, belonging to different eigenvalues. Using the perturbation theory and the adiabatic approximation, we get a general expression of the jump probability between different Zeno subspaces. We applied this result in an interesting practical example. In this example, as the coupling constant of the interaction increases, the measurement keeps the system remaining in its initial subspace and the quantum Zeno effect takes place.