TY  - JOUR
A1  - Ionescu, Dorin Cezar
A1  - Greiner, Walter
A1  - Müller, Berndt
A1  - Soff, Gerhard
T1  - Collective excitations of the QED vacuum
T2  - Physical review A
N2  - Using relativistic Green’s-function techniques we examined single-electron excitations from the occupied Dirac sea in the presence of strong external fields. The energies of these excited states are determined taking into account the electron-electron interaction. We also evaluate relativistic transition strengths incorporating retardation, which represents a direct measure of correlation effects. The shifts in excitation energies are computed to be lower than 0.5%, while the correlated transition strengths never deviate by more than 10% from their bare values. A major conclusion is that we found no evidence for collectivity in the electron-positron field around heavy and superheavy nuclei.
Y1  - 2006
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/2669
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30-29915
VL  - 47
IS  - 2
SP  - 854
EP  - 867
ER  -