中文摘要：

在这份报纸，我们调查动态集体产生在(2+1 ) 在有限温度的维的量 electrodynamics。许多研究在即时交换的近似以内被执行，它几乎忽略波色子增殖者和费米子自我精力功能的零频率的部件。我们由考虑延迟效果扩大这些研究。在这份报纸，我们得到费米子自我精力功能的明确的频率 n 和动量 p 依赖并且在 chiral 限制为不同费米子风味识别批评温度。另外，为自发的对称在理论碎的阶段图在 T _c -N _f 空间。结果证明 chiral 冷凝物只是以前的结果的规模的十分之一，并且 chiral 对称在更小的批评温度被恢复。

英文摘要：

In this paper, we investigate dynamical mass generation in（2＋1）-dimensional quantum electrodynamics at finite temperature. Many studies are carried out within the instantaneous-exchange approximation, which ignores all but the zero-frequency component of the boson propagator and fermion self-energy function. We extend these studies by taking the retardation effects into consideration. In this paper, we get the explicit frequency n and momentum p dependence of the fermion self-energy function and identify the critical temperature for different fermion flavors in the chiral limit. Also, the phase diagram for spontaneous symmetry breaking in the theory is presented in Tc-Nf space. The results show that the chiral condensate is just one-tenth of the scale of previous results, and the chiral symmetry is restored at a smaller critical temperature.