Kaon weak interactions in powers of 1/Nc
  I review a recent analytic method for computing matrix elements of electroweak operators based on the large-Nc expansion. In particular, I give a rather detailed description of the matching of the quark Lagrangian onto the meson chiral Lagrangian governing K0-K0bar mixing. In the DeltaS=1 sector, I explain how to obtain an estimate for both epsilon'/epsilon and the DeltaI=1/2 rule. Finally, I give an example of how the method can also be useful for lattice calculations. 
S. Peris (UAB and Ifae)