We obtain a general result for the Lamb shift of excited states of multilevel atoms in inhomogeneous electromagnetic structures and apply it to study atomic hydrogen in inverse-opal photonic crystals. We find that the photonic-crystal environment can lead to very large values of the Lamb shift, as compared to the case of vacuum. We also suggest that the position-dependent Lamb shift should exte...

The Lamb shift in muonic hydrogen continues to be a subject of experimental and theoretical investigation. Here my older work on the subject is updated to provide a complementary calculation of the energies of the 2p-2s transitions in muonic hydrogen. Introduction The energy levels of muonic atoms are very sensitive to effects of quantum electrodynamics (QED), nuclear structure, and recoil, sin...

Corrections to hyperfine splitting and Lamb shift of order α(Zα) induced by the diagrams with radiative photon insertions in the electron line are calculated in the Fried-Yennie gauge. These contributions are as large as −7.725(3)α(Zα)/(πn)(mr/m) m and −0.6711(7)α(Zα)/(πn)EF for the Lamb shift and hyperfine splitting, respectively. Phenomenological implications of these results are discussed wi...

The Lamb shift, an energy shift arising from the presence of electromagnetic vacuum, has been observed in various quantum systems and established as part independent environmental photon number. However, typical studies are based on simplistic bosonic models which may be challenged practical devices. We demonstrate a hybrid bosonic-fermionic environment for linear resonator mode observe that nu...

The proton structure and proton polarizability corrections to the Lamb shift of electronic hydrogen and muonic hydrogen were evaluated on the basis of modern experimental data on deep inelastic structure functions. Numerical value of proton polarizability contribution to (2P-2S) Lamb shift is equal to 4.4 GHz.