Limits of the Quantum Monte Carlo method

We consider the one-dimensional quantum-statistical problem of interacting spin-less particles in an infinite deep potential valley and on a ring. Several limits for the applicability of the Quantum Monte Carlo (QMC) methods were revealed and discussed. We show the inapplicability of the QMC method for ring-like geometries, realize an unphysical frustration for interacting fermions and a minus-sign problem for interacting bosons.