We discuss the occurrence of Bose-Einstein condensation in systems of
noninteracting charged particles in three in one dimensions and in presence of
an external magnetic field. In the one dimensional, as well as in the magnetic
field cases, although not a critical temperature, a characteristic temperature
can be found, corresponding to the case in which the ground state density
becomes a macroscopic fraction of the total density. The case of relativistic
charged scalar and vector particles is studied. The results obtainedgive
support to the existence of superconductivity in extremely strong magnetic
fields, and leads to the prediction of superconductive-ferromagnetic behavior
in the vector field case, which might be of interest in condensed matter as
well as in cosmology. Some features of the magnetization in the early universe
are conjectured.Comment: 20 pages, 2 GIF figure