ar X iv : h ep - p h / 99 05 36 2 v 1 1 7 M ay 1 99 9 Gauge Independence of Limiting Cases of One - Loop Electron Dispersion Relation in High - Temperature QED

Assuming high temperature and taking subleading temperature dependence into account, gauge dependence of one-loop electron dispersion relation is investigated in massless QED at zero chemical potential. The analysis is carried out using a general covariant gauge. It is proved that the high-momentum limit of the dispersion relation is gauge independent. It is also shown that the effective mass is not influenced by the leading temperature dependence of the gauge dependent part of the self-energy. As a result the effective mass, which is of order eT , does not receive a correction of order e2T from one loop, independent of the gauge parameter. E-mail: [email protected]