Description:
<jats:p>We prove, in great generality, that in a system of bosons, whenever Bose condensation in a nonzero mode occurs then there is also spontaneous breaking of translation symmetry. In particular the proof holds for realistic Bose systems with two-body superstable interaction. This generalizes an old result proving that the occurrence of Bose-Einstein condensation in the zero mode implies spontaneous breaking of gauge invariance.</jats:p>