Neutrino self-energy in a magnetized medium in arbitrary xi-gauge

We calculate the one-loop neutrino self-energy in a magnetized plasma to all orders in the magnetic field. The calculation is done in a general gauge. We obtain the dispersion relation and effective potential for neutrinos in a CP-symmetric plasma under various conditions, and show that, while the self-energy depends on the gauge parameter $\xi$, the dispersion relation and effective potential to leading order are independent of it.