Gauge independence and relativistic dispersion equations in statistical QED

The gauge parameter dependence of the particle spectra in statistical QED i s revisited in a non-perturbative way and it is concluded that the electron spectra is gauge-parameter dependent, the physical spectra being obtained in the Landau gauge. We calculate in the one-loop approximation the gauge p arameter dependent behavior of the electron dispersion equation at finite t emperature and density, and consider the limit of T = 0 and high density af terwards. The curves obtained confirm the predictions of the general result s. (C) 1999 Published by Elsevier Science B.V. All rights reserved.