Speaker: Stefan Schaefer (DESY)
Title: Multilevel methods for QCD
Abstract: Lattice QCD computations of two-point functions suffer from a severe deterioration of the signal-to-noise ratio as the distance between the two points is increased. Since this deterioration is typically exponential in the distance, an exponentially growing number of measurements is needed to compensate for it, making calculations exceedingly expensive. Multi-level Monte Carlo techniques can mitigate the problem, but so far have not been amenable to fermionic observables. I give an introduction into the ideas behind multilevel techniques and demonstrate that such methods can also be used in quenched QCD.