VACUUM POLARIZATION AT FINITE TEMPERATURE AND DENSITY IN QED

We calculate to first order in α, finite temperature and density (FTD) corrections to vacuum polarization in the framework of QED. The limiting values of the vacuum polarization tensor when the temperature of the heat bath T is sufficiently high are subject to physical interpretation and compared to the previously existing works. The FTD corrections to the] electric permittivity, the magnetic permeability of the medium, the anomalous magnetic moment of the electron, the charge renormalization constant Z3, and the running coupling constant are also calculated and comparison with the previous work furnished wherever possible. © 1991.