Renormalization and radiative corrections at finite temperature reexamined

The problem of finite-temperature renormalization and radiative corrections in QED is reexamined. In this connection, we redo the calculation of electron self-energy by including the electron thermal factor $n_F$(E) explicitly and show that this leads to a generalization of certain existing results. Further, the radiative corrections to the decay rate of a scalar H→$e^{+}$ $e^{\mathrm{-}}$, is reexamined. It is shown that, in the present scheme of calculations, one can study this problem in relation to various temperature ranges including among them the temperature of the order of the electron mass.