The use of a fermion Green’s function involving no delta functions is demonstrated. This Green’s function is employed to compute the first order contribution to the vacuum polarization of the hydrogen Lamb shift. No infinities appear so that regularization is unnecessary. The numerical value of this contribution to the vacuum polarization is shown to be identical to the value obtained by regula...

Corrections of order α(Zα)m to the Lamb shift and corrections of order α3(Zα)EF to hyperfine splitting generated by the insertions of the three-loop one-particle reducible diagrams with radiative photons in the electron line are calculated. The calculations are performed in the Yennie gauge.

The two-loop self-energy correction is evaluated to all orders in Zα for the groundstate Lamb shift of H-like ions with Z ≥ 20, where Z is the nuclear charge number and α is the fine structure constant. The results obtained are compared with analytical calculations performed within the Zα-expansion.

Ultrasonic guided wave inspection is much more efficient than traditional point-bypoint examination. Guided waves can propagate over long distances from a single position, and therefore is a good method of evaluating thickness degradation, especially for large-area structures such as pipes and vessels. In this paper, guided wave thickness measurement potential is studied utilizing a peak freque...

The work is devoted to a consideration of the different determinations of the proton charge radius. It is demonstrated that the results from the elastic electron-proton scattering have to be of a higher uncertainty. A review of the hydrogen Lamb shift measurements and the radius determination from them is also presented.

We discuss recent progress in various problems related to bound-state quantum electrodynamics: the bound-electron g factor, two-loop self-energy corrections and the laser-dressed Lamb shift. The progress relies on various advances in the bound-state formalism, including ideas inspired by effective field theories such as Nonrelativistic Quantum Electrodynamics. Radiative corrections in dynamical...