Nonrelativistic quantum electrodynamic approach to polarizabilities of light atoms

We derive polarizabilities for light atoms and their relativistic and radiative corrections by using nonrelativistic quantum electrodynamics (NRQED). We find out that if we use NRQED directly on the polarizabilities, it will lead to gauge-dependent terms which should be cancelled out by summing all the Feynman diagrams. The elimination of these gauge-dependent terms will become very cumbersome in the calculations of relativistic and radiative corrections. By combining the PowerZienau-Woolley transformation with NRQED, we have simplified this process. In addition to this, the combination allows us to obtain not only the electric dipole polarizability but also other kinds of polarizabilities, such as magnetic, Coulomb-transversal and hyperpolarizabilities, in a unified way. In the following article we introduce this combined method and show a systematic procedure to derive the polarizabilities as well as the relativistic, radiative corrections to some of them.