Question

I am currently researching the generation of thermal mass in photons within the framework of quantum field theory at finite temperature. In such as formalism, one can define longitudinal and perpendicular masses, denoted by mL and mT respectively, with these masses being proportional to the projectors PμνL and PμνT

. My question pertains to determining the total photon thermal mass. Is it accurately represented as m2total=m2L+m2T, or is it given by mtotal=mL+mT, or perhaps another combination altogether?

I appreciate your assistance in clarifying this matter.

Thank you.

Answer 1

The total photon thermal mass at finite temperatures should consider the tensorial nature of longitudinal and transverse masses and is not simply an arithmetic or squared sum of mL and mT.

Step-by-step explanation:

When considering the generation of thermal mass in photons within the framework of quantum field theory at finite temperature, we recall that photons are massless particles in vacuum. However, at finite temperatures, due to interactions with other particles, effective masses can be attributed to them, denoted as longitudinal mass (mL) and transverse mass (mT), which are related to the polarization of the photon's electric field.

In this context, the total photon thermal mass is not simply an arithmetic sum of mL and mT, nor is it the sum of their squares. Rather, the longitudinal and transverse components relate to different physical phenomena and their contributions to the total thermal mass should be considered in terms of the relevant projectors PμνL and PμνT.

When discussing these masses, the correct representation of the total photon thermal mass needs to account for the tensorial nature of these quantities and is likely to be a more complex combination than straightforward addition.