Cerenkov Radiation in a Lorentz-Violating and Birefringent Vacuum

We calculate the emission spectrum for vacuum Cerenkov radiation in Lorentz-violating extensions of electrodynamics. We develop an approach that works equally well if the presence or the absence of birefringence. In addition to confirming earlier work, we present the first calculation relevant to Cerenkov radiation in the presence of a birefringent photon k_F term, calculating the lower-energy part of the spectrum for that case.