Finite Temperature Effects in Quantum Field Theory

Abstract We consider quantum electrodynamics at finite temperatures. By making use of the real time formalism we compute, on the one-loop level, the finite-temperature correction to the mass of the electron and to the anomalous magnetic moment a e th . The gauge-invariant correction to the electron mass is found to be a ten percent effect at a temperature of the order of 2×10 10 K. Some astrophysical implications of this result are briefly discussed. The leading temperature correction to the anomalous magnetic moment of the electron is, at a temperature of 300 K, found to be one order of magnitude smaller than the τ -lepton contribution to a e th .