Conductivity of a Hot Electron Gas

The dissipative part of the high-frequency wave-number-dependent conductivity tensor of a hot, dilute electron gas near equilibrium is calculated exactly to terms proportional to the plasma parameter $\frac{{k_D}^3}{n}$ (the inverse of the number of particles in a Debye sphere), in the limit of classical statistics. The calculation includes high-frequency collective dynamic screening effects consistently to this order. These collective effects have an important effect on the frequency dependence of the conductivity for frequencies greater than about twice the electron-plasma frequency.