  An efficient Path Integral Monte Carlo procedure is proposed to simulate the
behavior of quantum many-body dissipative systems described within the
framework of the influence functional. Thermodynamic observables are obtained
by Monte Carlo sampling of the partition function after discretization and
Fourier transformation in imaginary time of the dynamical variables. The method
is tested extensively for model systems, using realistic dissipative kernels.
Results are also compared with the predictions of a recently proposed
semiclassical approximation, thus testing the reliability of the latter
approach for weak quantum coupling. Our numerical method opens the possibility
to quantitatively describe real quantum dissipative systems as, e.g., Josephson
junction arrays.
