Properties of P-vortex and monopole clusters in lattice SU(2) gauge   theory
  We study the action and geometry of P-vortices, discriminating between the percolating and finite clusters. We also discuss the interrelation of the monopoles and P-vortices. To define P-vortices we use both the direct maximal center projection and indirect maximal center projection. We find, in particular, that the action density of the P-vortices in short clusters is substantially higher than in the percolating cluster. The surface of the percolating cluster appears random at short distances, with action density depending on the shape. 
A. V. Kovalenko, M. I. Polikarpov, S. N. Syritsyn and V. I. Zakharov