Condensation and Magnetization of the Relativistic Bose Gas
  We present a simple proof of the absence of Bose--Einstein condensation of a relativistic boson gas, in any finite local magnetic field in less than five dimensions. We show that the relativistic charged boson gas exhibit a genuine Meissner--Ochsenfeld effect of the Schafroth form at fixed supercritical density. As in the well--known non--relativistic case, this total expulsion of a magnetic field is caused by the condensation of the Bose gas at vanishing magnetic field. The result is discussed in the context of kaon condensation in neutron stars. 
P.Elmfors, P.Liljenberg, D.Persson and B.-S.Skagerstam