A local factorization of the fermion determinant in lattice gauge theories

The numerical computations of many interesting theoretical and phenomenological
quantities, such as the static potential, vacuum polarization,
semileptonic form factors etc., are affected by an exponential degradation of
the signal to noise ratio. Reliable and precise determinations of these quantities
are very difficult if not impractical with standard Monte Carlo
integration schemes.
I will discuss a recent proposal for factorizing the fermion determinant in
lattice QCD with Wilson-type fermions that leads to a bosonic action
which is local in the block fields. The combination of the determinant
and the propagator factorizations paves the way for multilevel Monte Carlo
integration in the presence of fermions, opening new perspectives in lattice QCD.