Igor Goidenko

SECOND-ORDER ELECTRON SELF-ENERGY IN HYDROGENLIKE IONS

A calculation of the simplest part of the second-order electron self-energy (loop after loop irreducible contribution) for hydrogen-like ions with nuclear charge numbers

Multiple commutator expansion for the Lamb shift in a strong Coulomb field

3 \leq Z \leq 92

Estimate of the second order electron self energy corrections in highly charged heavy ions

is presented. This serves as a test for the more complicated second-order self-energy parts (loop inside loop and crossed loop contributions) for heavy one-electron ions. Our results are in strong disagreement with recent calculations of Mallampalli and Sapirstein for low

Electron self-energy calculations for tightly bound electrons in atoms

Z

The non-resonant corrections to the process of the radiative electron capture of highly charged heavy ions

values but are compatible with the two known terms of the analytical

Effects of QED and Beyond from the Atomic Binding Energy

Z\alpha

Evaluation of the Two-Photon Self-Energy Correction for Hydrogenlike Ions

-expansion.

QED Effects in Heavy Elements

A new expression for the electron self-energy in a strong Coulomb field is obtained without expansion in powers of ( is the fine structure constant, Z is the charge of the nucleus). This expression contains the multiple commutator expansion, which differs from the expansion and converges rapidly even for very high Z values. The renormalization procedure requires the proof of a new sum rule. This proof is given explicitly for Z = 1 and implicitly for all Z values for the state. The numerical calculation of the Lamb shift for different Z values is performed and comparison with the known results made.

QED Effects in Atoms

An estimate for the last unknown gauge-invariant set of QED corrections of order α2, the second-order self-energy correction, is presented utilizing the so-called sign approximation. This is able to reduce the present uncertainties in Lamb-shift predictions considerably.

CALCULATED SELF-ENERGY CONTRIBUTIONS FOR AN NS VALENCE ELECTRON USING THE MULTIPLE-COMMUTATOR METHOD

A new method for the calculation of the self-energy for tightly bound electrons is presented. The method is based on the multiple commutator expansion and the partial-wave renormalization. The numerical calculations are performed for hydrogen-like multicharged ions with nuclear charge Z from 10 to 100 for states with .