P-vortices, nexuses and effects of gauge copies
  We perform the careful study of the gauge copies problem for the direct center projection in SU(2) lattice gauge theory. Our results indicate that this gauge is not appropriate for the investigation of the center vortices. We also show that the point-like objects, nexuses, are important for the confinement dynamics. 
V. G. Bornyakov, D. A. Komarov, M. I. Polikarpov and A. I. Veselov