Expanding upon previous work, using the path-integral formalism we derive expressions for the one-particle reduced density matrix and the two-point correlation function for a quadratic system of bosons that interact through a general class of memory kernels. The results are applied to study the density, condensate fraction, and pair correlation function of trapped bosons harmonically coupled to external distinguishable masses.

• Received 1 September 2021
• Accepted 19 November 2021

DOI:https://doi.org/10.1103/PhysRevA.104.062201