We report recent progress in computer simulations of quantum systems
described in the path-integral formulation. For the example of the Ï•4
quantum chain we show that the accuracy of the simulation may greatly be
enhanced by a combination of multigrid update techniques with a refined
discretization scheme. This allows us to assess the accuracy of a variational
approximation.Comment: 5 pages, LaTeX + 2 postscript figures. Talk presented by TS at "Path
Integrals from meV to MeV: Dubna '96". See also
http://www.cond-mat.physik.uni-mainz.de/~janke/doc/home_janke.htm