Fractionalized Degrees of Freedom at Infinite Coupling in large Nf QED in 2+1 dimensions

Understand

I consider quantum electrodynamics with many electrons in 2+1 space-time dimensions at finite temperature.

• The relevant dimensionless interaction parameter for this theory is the fine structure constant divided by the temperature.
• The theory is solvable at any value of the coupling, in particular for very weak (high temperature) and infinitely strong coupling (corresponding to the zero temperature limit).
• Concentrating on the photon, each of its physical degrees of freedom at infinite coupling only contributes half of the free-theory value to the entropy.