The thermal gap equation in the massless λ D4 model

Using the Dyson–Schwinger equation, we re-examine the behavior of the massless λ 4 model in a generic D-dimensional Euclidean space at finite temperature. An analysis of the thermal behavior of the renormalized self-energy is done for all temperatures. It is found that the thermal renormalized self-energy is positive and increases monotonically with the temperature.