Note Added to ``Baryon Asymmetry of the Universe in the Standard Model"
  Recent papers by Gavela et al. and Huet et al. claim to have shown that incluion of higher order interactions between quasiparticles dramatically decreases the baryon asymmetry of the universe which can arise in the Minimal Standard Model. These papers employ an inconsistent calculational scheme which, for instance, violates unitarity. We argue that their method cannot be considered as reliable, and thus their conclusions cannot be considered as justified. 
G. R. Farrar and M. E. Shaposhnikov