Summary:
An exact expression for the average energy exchange in a relativistic two-body collision between isotropic particle distributions is calculated. This is used to find the relaxation time-scale for particles with a Maxwellian distribution function. These time-scales are compared with important energy loss time-scales at temperatures \(kT/m_e c^2 \gtrsim 1\).
full paper : scanned PDF 959K | a much extended version appears as chapters 2-4 of Relativistic Thermal Plasmas
@journal(SS-MNRAS-202, author = "Susan Stepney", title = "Two-body relaxation in relativistic thermal plasmas", journal = "Monthly Notices of the Royal Astronomical Society", volume = 202, pages = "467--481", year = 1983 )