Multigrid method versus staging algorithm

We present a comparison of the performance of two non-local update algorithms for path integral Monte Carlo (PIMC) simulations, the multigrid Monte Carlo method and the staging algorithm. Looking at autocorrelation times for the internal energy we show that both refined algorithms beat the slowing down which is encountered for standard local update schemes in the continuum limit. We investigate the conditions under which the staging algorithm performs optimally and give a brief discussion of the mutual merits of the two algorithms.