Collisional Energy Loss of Fast Charged Particles in Relativistic Plasmas

Following an argument by Kirzhnits we rederive an exact expression for theenergy loss of a fast charged particle in a relativistic plasma using thequantum field theoretical language. We compare this result to perturbativecalculations of the collisional energy loss of an energetic electron or muon inan electron-positron plasma and of an energetic parton in the quark-gluonplasma.