Power corrections to the HTL effective Lagrangian of QED

Understand

We present compact expressions for the power corrections to the hard thermal loop (HTL) Lagrangian of QED in $d$ space dimensions.

• These are corrections of order $(L/T)^2$, valid for momenta $L \ll T$, where $T$ is the temperature.
• In the limit $d\to 3$ we achieve a consistent regularization of both infrared and ultraviolet divergences, which respects the gauge symmetry of the theory.
• Dimensional regularization also allows us to witness subtle cancellations of infrared divergences.