CONDENSATION AND MAGNETIZATION OF THE RELATIVISTIC BOSE-GAS

We show that the relativistic charged scalar boson gas exhibits a genu ine Meissner-Ochsenfeld effect of the Schafroth form at fixed supercri tical density. As in the well-known non-relativistic case, this total expulsion of a magnetic field is caused by the condensation of the Bos e gas at vanishing magnetic held. In the course of these consideration s, we present alternative proofs of the absence of Bose-Einstein conde nsation of a relativistic scalar boson gas, in any finite local magnet ic field in less than five dimensions. The results are discussed in th e context of kaon condensation in neutron stars.