In an assembly of non-interacting subatomic particles of integer spin, the fraction of particles in their ground state, which is normally very close to zero, begins to grow significantly as the temperature drops below the critical temperature or T sub not.  
In an assembly of non-interacting subatomic particles of integer spin, the fraction of particles in their ground state, which is normally very close to zero, begins to grow significantly as the temperature drops below the critical temperature or T sub not.  This corresponds to a first-order phase transition in momentum space, since the condensed phase has no volume.  FTP, what is this abrupt transition of an ideal gas of bosons into its ground state, predicted early in the twentieth century but first produced in 1995 via magnetic cooling?
In an assembly of non-interacting subatomic particles of integer spin, the fraction of particles in their ground state, which is normally very close to zero, begins to grow significantly as the temperature drops below the critical temperature or T sub not.  
{Bose-Einstein} condensation or BEC