Photons and leptons in external fields at finite temperature and density

Theoretical aspects of the propagation of photons, electrons, and neutrinos in external electromagnetic fields at finite temperature and density are considered. The photon polarization operator and the radiative mass shifts and anomalous magnetic moments of the electron and the massive neutrino are investigated based on the finite-temperature quantum field theory with the use of exact solutions of the relativistic equations of motion for particles in external fields of various configurations. The present approach permits using model results as reference ones for experimental data as well as presenting a wider choice of interpretations for the results obtained.