Center Vortices and Monopoles without lattice Gribov copies
  We construct a smooth gauge for the adjoint field which is free of ambiguities on the lattice. In this Laplacian Center Gauge, center vortices and monopoles appear together as local gauge defects. A numerical study of center vortices in SU(2) and SU(3) supports equality of the $Z_N$ and SU(N) string tensions in the continuum limit, and only then. 
Ph. de Forcrand (ETH and CERN) and M. Pepe (ETH)