标题： 红外发散在有限温度下的消除 显示英文标题

标题： Cancellation of infrared divergences at finite temperature

摘要： 我们考虑在温度为$T$的光子和电子热浴中的典型硬散射过程，在有限温度QED中。 我们证明，当硬散射尺度远大于温度时，截面实部和虚部的红外部分可以分离；这些部分可以指数化，并在微扰理论的所有阶数中相互抵消。 我们使用Grammer和Yennie的技术来给出红外发散部分的提取方法以及有限余项的形式。 对称性论证被用来证明计算中$T \neq 0$部分出现的新项的有限性。 显示英文摘要

摘要： We consider a typical hard scattering process in a heat bath of photons and electrons at temperature, $T$, in finite temperature QED. We show that, when the hard scattering scale is much larger than the temperature, the infrared pieces of both the real and virtual parts of the cross section factorise; these can be exponentiated and cancel between each other to all orders in perturbation theory. We use the technique of Grammer and Yennie to give a prescription for the extraction of the infrared divergent parts, and for the form of the finite remainder. Symmetry arguments are used to show the finiteness of new terms arising in the $T \neq 0$ part of the computation.