Computer Simulations of Quantum Chains
  We report recent progress in computer simulations of quantum systems described in the path-integral formulation. For the example of the $\phi^4$ 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. 
Wolfhard Janke, Tilman Sauer (JGU Mainz, FU Berlin)