On Some Features of Color Confinement
  It is argued that a dual symmetry is needed to naturally explain experimental limits on color confinement. Since color is an exact symmetry the only possibility is that this symmetry be a dual symmetry, related to non trivial spatial homotopy. The sphere at infinity of 3-dimensional space being 2-dimensional, the relevant homotopy is $\Pi_2$, the corresponding configurations monopoles, and the mechanism dual superconductivity. The consistency of the order-disorder nature of the deconfining transition is compared with lattice data . It is also shown that the only dual quantum number is magnetic charge and the key quantity is 't Hooft tensor, independent of the gauge group. The general form of the 't Hooft tensor is computed. 
A. Di Giacomo