A Random Point Field related to Bose-Einstein Condensation
  The random point field which describes the position distribution of the system of ideal boson gas in a state of Bose-Einstein condensation is obtained through the thermodynamic limit. The resulting point field is given by convolution of two independent point fields: the so called boson process whose generating functional is represented by inverse of the Fredholm determinant for an operator related to the heat operator and the point field whose generating functional is represented by a resolvent of the operator. The construction of the latter point field in an abstract formulation is also given. 
H. Tamura, and K.R. Ito