We investigate the properties of two standard energy estimators used in path-integral Monte Carlo simulations. By disentangling the variance of the estimators and their autocorrelation times we analyse the dependence of the performance on the update algorithm and present a detailed comparison of refined update schemes such as multigrid and staging techniques. We show that a proper combination of the two estimators leads to a further reduction of the statistical error of the estimated energy with respect to the better of the two without extra cost.
@article{arxiv.cond-mat/9710117,
title = {Optimal Energy Estimation in Path-Integral Monte Carlo Simulations},
author = {Wolfhard Janke and Tilman Sauer},
journal= {arXiv preprint arXiv:cond-mat/9710117},
year = {2009}
}