The phase transition in nonperturbative quantum electrodynamics at T not = 0

The possibility of a phase transition at T not= 0 in QED4 with the dynamically broken chiral symmetry at T not = 0 is considered. The Schwinger - Dyson equation is used for the electron temperature Green's function in the ladder approximation with the Landau gauge and the possibility of neglecting the effective temperature-dependent photon mass is discussed. As to the structural functions of the temperature self-energy integral, the values at T=0 are taken for them excepting the mass function that is interpreted in spirit of the bifurcation theory and justified by the found value of the critical temperature Tc. It turns out that Tc = Cm(0), where C ∼ 1 and m(0) is the dynamical electron mass at T=0. The connection of this result with one for (2+1) QED and with results of the calculation of a critical temperature in QCD4 within the bootstrap method is discussed. One of possible methods is denoted for obtaining the gauge invariant result for Tc