  We derive closed analytical formulae for the power emitted by moving charged
particles in a uniaxial wire medium by means of an eigenfunction expansion. Our
analytical expressions demonstrate that in the absence of material dispersion
the stopping power of the uniaxial wire medium is proportional to the charges
velocity, and that there is no velocity threshold for the Cherenkov emission.
It is shown that the eigenfunction expansion formalism can be extended to the
case of dispersive lossless media. Furthermore, in presence of material
dispersion the optimal charge velocity that maximizes the emitted Cherenkov
power may be less than the speed of light in vacuum.
